Source: FOREST PRODUCTS LABORATORY submitted to NRP
NANOSCALE PROCESSING AND PROPERTIES
Sponsoring Institution
Forest Service/USDA
Project Status
COMPLETE
Funding Source
USDA INHOUSE
Reporting Frequency
Annual
Accession No.
0419191
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Oct 1, 2012
Project End Date
Sep 30, 2022
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
FOREST PRODUCTS LABORATORY
ONE GIFFORD PINCHOT DRIVE
MADISON,WI 53726
Performing Department
(N/A)
Non Technical Summary
The concept is that there is some intentional ⿿control⿝ of the nano-feature that is being investigated such that it can be individually and independently varied and characterized, so that processing-structure-property relationships can be formulated. There is insufficient understanding of wood and lignocellulosic materials at the nanoscale dimensions to develop the necessary structure-property relationships needed to systematically solve end-use performance problems.
Animal Health Component
20%
Research Effort Categories
Basic
70%
Applied
20%
Developmental
10%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1230650200033%
1230650201033%
1230650202034%
Knowledge Area
123 - Management and Sustainability of Forest Resources;

Subject Of Investigation
0650 - Wood and wood products;

Field Of Science
2010 - Physics; 2020 - Engineering; 2000 - Chemistry;
Goals / Objectives
Nanotechnology is the study and manipulation of the unique physical, chemical, and biological properties of matter at the dimensions of (1 to 100) x 10-9 meters (nanometers) where these properties are often fundamentally different from that of the bulk. By expanding our understanding, characterization and control of matter at such levels, new avenues in basic research, applied research and product development can be achieved. Nanotechnology research is not an ends to itself, but rather a means to an end to help advance the science and technology needed to support problem areas 1 and 2. Nanotechnology research is considered here to represent studies that entail the intentional manipulation of a specified nano-feature, which can be uniquely characterize by some given technique and relate this to changes at nano, micro (problem area 2), and/or macroscopic properties (problem area 3). The concept is that there must be some intentional ⿿control⿝ of the nano-feature that is being investigated such that it can be individually and independently varied and characterized, so that processing-structure-property relationships can be formulated. Distinction should be made for ⿿chemistry⿝ related activities (such as colloidal science, self-assembly, etc.), which also fundamentally occur at this length scale. These are classified here as tools used in the production or modification of nanostructures (e.g. the arrangement or self-assembly of chemical species on the surface of a nanoparticle) not as a form of nanotechnology as they are ⿿a means⿝ but are not ⿿the end⿝. Stating this more specifically, the end is the nanoscale or nanostructured object of the study and manipulation with the unique properties often observed at this length scale. Therefore, all processes used to create, modify, etc. nanostructure will not necessarily be categorized as a length scale specific activity.
Project Methods
Widely varied.

Progress 10/01/12 to 09/30/22

Outputs
OUTPUTS: TEMPO-oxidized cellulose nanofibril (TOCNF) films has been limited by their brittleness and the inability to produce materials thick enough for self-supported applications. Lamination with epoxies was successful at increasing the toughness and thickness of TOCNF composites, resulting in an increased work of fracture that was associated with fracture retardation by crack digression in three-point bending specimens. Low amounts of epoxy were most successful in retaining the beneficial properties of the TOCNF, while still overcoming their limitations. Extrusion-based processes with a conventional single-screw extrusion was used for continuously processing mechanically fibrillated cellulose nanofibrils (CNFs) into wet sheets. A high shear mixing procedure was used to process highly loaded CNF pastes with up to ⿼25 wt % solids, composed of ⿼91 wt % CNF and ⿤⿼9 wt % of a processing aid like carboxymethyl cellulose (CMC). Tensile testing of the pressed and heated CNF/CMC extrudates revealed equivalent mechanical properties to cast CNF films prepared through conventional solution casting, with faster processing and drying times. Polylactic acid (PLA) has generated interest because it can be synthesized from corn, but PLA is a slow crystallizing polymer and without additives to increase the rate of crystallization, crystallinity in PLA is typically low after processing. Increasing the crystallinity would improve performance. While cellulose nanocrystals and cellulose nanofibrils improved crystallization rates, additional small amounts of polyethylene glycol exhibited a synergistic effect on the crystallization kinetics of PLA to further speed crystallization. This allows PLAs to be used in making consumer products more rapidly and expand their markets. A simple method for self-assembly of nanocellulose and nanochitin was developed to produce high-e﬿ciency and versatile biohybrid hydrogel and aerogel (BHA) for water purification. The self-assembly process was driven by the electrostatic force between one-dimensional negatively charged TEMPO-oxidized cellulose nanofiber and positively charged partly deacetylated chitin nanofiber. The polysaccharide chitin is a primary component of crustacean shells. This versatile BHA produced via a facile preparation strategy is proven to be a promising renewable adsorbent for water purification, o﬿ering simple and green alternatives to the conventional adsorbent from synthetic polymers. PARTICIPANTS: Army Research Laboratory, Adelphi, MD; Grain Processing Corporation, Muscatine, IA; Mississippi State University, Mississippi State, MS; Purdue University, West Lafayette, IN; University of Maine, Orono, ME. TARGET AUDIENCES: The research conducted in this problem area covers both fundamental/basic and applied focus areas. Much of the CN research is applicable to the forest product industry as a supplier and the traditional petrochemical materials markets as a biobased replacement or augment for materials traditionally used in market segments where wood products find no to limited utilization. Therefore, the target audience ranges from fellow researchers to industry product developers and product managers. PROJECT MODIFICATIONS: This problem area is fundamental and will be continued in our Research Work Unit Description. We will be reviewing and revising our Research Work Unit Description in 2021.

Impacts
The study of nanoscale features and materials within and extractable from wood is key to future development of new products that can revitalize the forest products sector within the US. The advantageous properties and uniformity of wood-based nanomaterials allows wood to be used in the large volume and diverse markets traditionally reserved for petrochemical derived materials. Thus, the applied and fundamental research conducted on nanoscale materials is vitally important.

Publications

  • Clarkson, Caitlyn M.; El Awad Azrak, Sami M.; Schueneman, Gregory T.; Snyder, James F.; Youngblood, Jeffrey P. 2020. Crystallization kinetics and morphology of small concentrations of cellulose nanofibrils (CNFs) and cellulose nanocrystals (CNCs) melt-compounded into poly(lactic acid) (PLA) with plasticizer. Polymer. 187: 122101. https://doi.org/10.1016/j.polymer.2019.122101.
  • El Awad Azrak, Sami M.; Costakis, William J.; Moon, Robert J.; Schueneman, Gregory T.; Youngblood, Jeffrey P. 2020. Continuous processing of cellulose nanofibril sheets through conventional single-screw extrusion. ACS Applied Polymer Materials. 2(8): 3365-3377.
  • Forti, Endrina S.; Moon, Robert J.; Schueneman, Gregory T.; Youngblood, Jeffrey P. 2020. Transparent tempo oxidized cellulose nanofibril (TOCNF) composites with increased toughness and thickness by lamination. Cellulose. 27(8): 4389-4405. https://doi.org/10.1007/s10570-020-03107-8.
  • Zhang, Xuefeng; Elsayed, Islam; Navarathna, Chanaka; Schueneman, Gregory T.; Hassan, EI Barbary. 2019. Biohybrid hydrogel and aerogel from self-assembled nanocellulose and nanochitin as a high-efficiency adsorbent for water purification. ACS Applied Materials & Interfaces. 11(50): 46714-46725. https://doi.org/10.1021/acsami.9b15139.


Progress 10/01/12 to 09/30/19

Outputs
OUTPUTS: Nanocellulose is a promising nanomaterial for vehicle light weighting as it exhibits a high strength to weight ratio and, as a plant-based biomaterial, can be produced abundantly and renewably. Researchers enhanced the fiber-matrix adhesion in fiberglass composites by incorporating nanocellulose on the glass fiber (GF) surface. Chemical and mechanical characterization shows that nanocellulose does indeed enhance the interface, and this effect can be tuned through adjustment of nanocellulose surface chemistry. Looking further at the addition of cellulose nanocrystal (CNC)s to various fiberglass formulas, the properties of GF/epoxy sheet molding compound composites were enhanced while those of basalt fiber/epoxy sheet-molding compound composites deteriorated. Alternatively, the CNC can be coated onto GF. This study found that the emulsion and aqueous coatings containing functionalized CNCs improved the interfacial shear strength. Mechanically fibrillated CNF sheets of varying thicknesses were fabricated by using a wet stacking lamination technique without the use of solvents. This technique produced laminates with a working area of 117 mm by 117 mm and thickness of up to 0.547 ± 0.03 mm in under 2 h. The ultimate strength increased as the thickness increased and had a specific strength comparable to 2024 aluminum (T3 tempered). Functionalized CNCs were studied as a potential reinforcement for an UPR. Three surface chemistries were explored. With the addition of 1 wt.% CNCs, the flexural and tensile modulus increased by up to 53% and 22%, respectively. Dynamic mechanical analysis indicated that the PhCNC- and MCNC-UPR samples had a 61% and 66% higher glassy modulus than neat UPR, respectively. Despite the lack of nano-scale dispersion. A dual approach was employed to incorporate CNFs into polylactic acid (PLA). Polyethylene glycol acted as a compatibilizating agent to enable the melt spinning of CNF/PLA composite fibers without water/solvent, and CNFs were surface modified to improve compatibility. While no significant difference was observed in strength, the stiffness improved up to 600% in the composite fibers. Dry-spinning was evaluated for the production of CNC and PLA composite fibers from dimethylformamide solutions. A maximum average elastic modulus of 65 GPa and 100 MPa increase in strength at failure are reported for dry-spun composite fibers A new method is described for producing high-lignin-containing and lignin-free cellulose nanocrystals from poplar wood. This was accomplished by first hydrothermally treating the poplar wood fibers at 170 C for 45 min in a Parr reactor. The first comparative exploration on lignin containing CNF films prepared alternatively from willow bark and wood was conducted. The study used a highly recyclable acid hydrotrope, aqueous p-toluene sulfonic acid, as a sustainable means for isolating the CNFs. The CNFs of willow bark were hydrophobic and produced dense films of high strength under hot pressing. PARTICIPANTS: George Woodruff School of Mechanical Engineering, and Department of Materials Science and Engineering, Georgia Institute of Technology, The 3M Company, Maplewood, MN, School of Materials Engineering, Purdue University, West Lafayette, IN, School of Materials Engineering, Purdue University, West Lafayette, IN, Army Research Laboratory, Adelphi, MD, 4709 TARGET AUDIENCES: The research conducted in this problem area covers both fundamental/basic and applied focus areas. Secondly, much of the CN research is applicable to the forest product industry as a supplier and the traditional petrochemical materials markets as a biobased replacement or augment for materials traditionally used in market segments where wood products find no to limited utilization. Therefore, the target audience is ranges from fellow researchers to industry product developers and product managers.

Impacts
The study of nanoscale features and materials within and extractable from wood is key to future development of new products that can revitalize the US forest products sector. The advantageous properties and uniformity of wood based nanomaterials allows wood to be used in the large volume and diverse markets traditionally reserved for petro chemical derived materials. Thus, the applied and fundamental research conducted on nanoscale materials is vitally important.

Publications

  • Agarwal, Umesh P.; Ralph, Sally A.; Reiner, Richard S.; Hunt, Christopher G.; Baez, Carlos; Ibach, Rebecca; Hirth, Kolby C. 2018. Production of high lignin-containing and lignin-free cellulose nanocrystals from wood. Cellulose. 25(10): 5791-5805.
  • Asadi, Amir; Baaij, Ferdinand; Moon, Robert J; Harris, Tequila AL; Kalaitzidou, Kyriaki. 2019. Lightweight alternatives to glass fiber/epoxy sheet molding compound composites: a feasibility study. Journal of Composite Materials. 53(14): 1985-2000.
  • Berman, Arielle; DiLoreto, Edward; Wu, Yong; Ista, Troy; D⿿Souza, Andrew; Moon, Robert; Kalaitzidou, Kyriaki. 2019. Processing of hollow glass sphere/polyester/glass fiber sheet molding composites. Conference Paper 1482. In: Proceedings, SAMPE 2019 Technical Conference & Exhibition. 11 p.
  • Clarkson, Caitlyn M.; El Awad Azrak, Sami M.; Chowdhury, Reaz; Shuvo, Shoumya Nandy; Snyder, James; Schueneman, Gregory; Ortalan, Volkan; Youngblood, Jeffrey P. 2019. Melt spinning of cellulose nanofibril/polylactic acid (CNF/PLA) composite fibers for high stiffness. ACS Applied Polymer Materials. 1(2): 160-168.
  • Clarkson, Caitlyn M; Youngblood, Jeffrey P.; Schueneman, Greg; Snyder, James. 2018. Corrigendum: dry-spinning of cellulose nanocrystal/polylactic acid composite fibers. Green Materials. 6(1): 47-47.
  • DiLoreto, Edward; Haque, Ejaz; Berman, Arielle; Moon, Robert J.; Kalaitzidou, Kyriaki. 2019. Freeze dried cellulose nanocrystal reinforced unsaturated polyester composites: challenges and potential. Cellulose. 26(7): 4391-4403.
  • Dou, Jinze; Bian, Huiyang; Yelle, Daniel J.; Ago, Mariko; Vajanto, Krista; Vuorinen, Tapani; Zhu, Junyong (J.Y.). 2019. Lignin containing cellulose nanofibril production from willow bark at 80⿿°C using a highly recyclable acid hydrotrope. Industrial Crops and Products. 129: 15-23.
  • El Awad Azrak, Sami M.; Clarkson, Caitlyn M.; Moon, Robert J.; Schueneman, Gregory T.; Youngblood, Jeffrey P. 2019. Wet-stacking lamination of multilayer mechanically fibrillated cellulose nanofibril (CNF) sheets with increased mechanical performance for use in high-strength and lightweight structural and packaging applications. ACS Applied Polymer Materials. 1(9): 2525-2534.
  • Goswami, Joyanta; Haque, Ejaz; Fox, Douglas M.; Gilman, Jeffrey W.; Holmes, Gale A.; Moon, Robert J.; Kalaitzidou, Kyriaki. 2019. The effect of cellulose nanocrystal coatings on the glass fiber⿿epoxy interphase. Materials. 12(12). 16 p.
  • Haque, Ejaz; Goswami, Joyanta; Moon, Robert J.; Fox, Douglas M.; Kalaitzidou, Kyriaki. 2019. Fiberglass composite reinforcement with nanocellulose fiber sizing. Conference Paper 1385. In: Proceedings, SAMPE 2019 Technical Conference & Exhibition. 8 p.


Progress 10/01/12 to 09/30/17

Outputs
OUTPUTS: Nanoscale Metrology: We discovered a transition in the relative wear resistance of the SiC samples compared to that of Si as a function of contact size. We attribute this to a transition from a wear regime dominated by the materials⿿ resistance to plastic deformation to a regime dominated by resistance to interfacial shear. Nanomaterial Composites: This research reports the influence of raw and sonicated cellulose nanocrystals (CNCs) on the micro-structure of cement paste. A novel centrifugation method is designed to measure the concentrations of the adsorbed CNCs (aCNCs) on the cement surface, and the free CNCs (fCNCs) which are mobile in water. It is found that, the majority of the CNCs (>94%) are aCNCs. More importantly, sonication does not significantly reduce the amount of aCNCs (reduction of less than 2%). Polyacrylonitrile-co-methacrylic acid (PAN-co-MAA) and CNC composite films were produced with up to 40 wt% CNC loading through the solution casting method. The glass transition temperature (Tg) increased from 92 to 118°C, and the composites had higher thermal stability below 350°C compared to both neat PAN-co-MAA and neat CNC. The mechanical properties also increased with higher CNC loadings. In an ancient fungus-cultivating termite system, we reveal unprecedentedly rapid lignin depolymerization and degradation by combining laboratory feeding experiments, lignocellulosic compositional measurements, electron microscopy, 2D-NMR, and thermochemolysis. In a gut transit time of under 3.5 h, in young worker termites, poplar lignin sidechains are extensively cleaved and the polymer is significantly depleted, leaving a residue almost completely devoid of various condensed units. We report the use of spray-dried lignin-coated CNCs (L-CNCs), a biobased filler, to modify the rheological and thermos-mechanical properties of poly(lactic acid) (PLA) composites. The lignin coating on CNCs not only improved the dispersion but also enhanced their interfacial interaction with the PLA matrix, resulting in a significant improvement in rheological and thermos-mechanical properties. The reaction of freeze dried CNCs with IPDI was optimized to yield modified cellulose particles with a high surface coverage of the di-functional monomer. The pendant primary isocyanate group was then used as a route to facilitate covalent bond formation with a polyurethane elastomer, resulting in a significant improvement in the tensile properties at 5 wt.% m-CNC com-pared to the neat matrix. Homogeneous and toughened cellulose-epoxy polymers were made by modifying an anhydride-cured epoxy with two green modifiers, microcrystalline cellulose (MCC) and CNC. Problems with sedimentation were resolved by the addition of (3-glycidyloxypropyl)trimethoxysilane (GPTMS) during the three-roll mill process yielding homogenously dispersed cellulose agglomerate particles. The addition of MCC or CNC decreased the glass transition temperature of the epoxy, but doubled the fracture energy. By comparison, the addition of 10 wt% of nanosilica only gave a 57% increase in fracture energy.

Impacts
The study of nanoscale features and materials within and extractable from wood is key to future development of new products that can revitalize the forest products sector within the US. The advantageous properties and uniformity of wood based nanomaterials allows wood to be used in the large volume and diverse markets traditionally reserved for petro chemical derived materials. Thus, the applied and fundamental research conducted on nanoscale materials is vitally important.

Publications

  • Asadi, Amir; Miller, Mark; Singh, Arjun V.; Moon, Robert J.; Kalaitzidou, Kyriaki. 2017. Lightweight sheet molding compound (SMC) composites containing cellulose nanocrystals. Composite Structures. 160: 211-219.
  • Cao, Yizheng; Tian, Nannan; Bahr, David; Zavattieri, Pablo D.; Youngblood, Jeffrey; Moon, Robert J.; Weiss, Jason. 2016. The influence of cellulose nanocrystals on the microstructure of cement paste. Cement and Concrete Composites. 74: 164-173.
  • Deng, Xinying; Kinloch, Anthony J.; Pimenta, Soraia; Schueneman, Gregory T.; Sprenger, Stephan; Taylor, Ambrose C.; Teo, Wern Sze. 2017. Homogeneous and toughened cellulose epoxy composites. In: Proceedings, 21st international conference on composite materials. 20-25 August 2017. Xi'an, China: 1-12 pp.
  • Girouard, Natalie; Schueneman, Greg; Shofner, Meisha; Meredith, Carson. 2017. Site selective modification of cellulose nanocrystals with isocyanate for adhesion applications. In: Proceedings of the 40th Annual Meeting of the Adhesion Society. St. Petersburg, FL. 3 p.
  • Gupta, Anju; Simmons, William; Schueneman, Gregory T.; Hylton, Donald; Mintz, Eric A. 2017. Rheological and thermo-mechanical properties of poly(lactic acid)/lignin-coated cellulose nanocrystal composites. ACS Sustainable Chemistry and Engineering. 5: 1711⿿1720.
  • Li, Hongjie; Yelle, Daniel J.; Li, Chang; Yang, Mengyi; Ke, Jing; Zhang, Ruijuan; Liu, Yu; Zhu, Na; Liang, Shiyou; Mo, Xiaochang; Ralph, John; Currie, Cameron R.; Mo, Jianchu. 2017. Lignocellulose pretreatment in a fungus-cultivating termite. Proceedings of the National Academy of Sciences. 114(18): 4709-4714.
  • Luo, Jeffrey; Chang, Huibin; Bakhtiary Davijani, Amir A.; Liu, H. Clive; Wang, Po-Hsiang; Moon, Robert J.; Kumar, Satish. 2017. Influence of high loading of cellulose nanocrystals in polyacrylonitrile composite films. Cellulose. 24(4): 1745-1758.
  • Tangpatjaroen, Chaiyapat; Grierson, David; Shannon, Steve; Jakes, Joseph E.; Szlufarska, Izabela. 2017. Size dependence of nanoscale wear of silicon carbide. ACS Applied Materials & Interfaces. 9(2): 1929-1940.


Progress 10/01/15 to 09/30/16

Outputs
OUTPUTS: Nanoscale Metrology: Using contact resonance atomic force microscopy we measured and mapped the transverse elastic modulus of three types of cellulosic nanoparticles. While intra-particle variations in modulus are detected, we did not observe a measureable difference in modulus between the three types of cellulose particles. Nanomaterial Composites: Films ⿿ Two patents were issued with RWU inventors on the formation of flat ⿿ low CTE films from cellulose nanocrystals (CNC) and the production of solar cells from these films. CNCs were incorporated into polyethylene oxide (PEO). The hydrophilic nature and long-range self-organization of CNCs facilitated structural control in the PEO matrix. The attained composite films were iridescent and exhibited a significant reduction in CTE even with low CNC addition (~50% CTE reduction at ~10 wt.% CNC load). With further control over nanoparticle processing, such composites promise potentials for selective optical bandgap materials while tuning the CTE. CNC/polylactic acid (PLA) films were fabricated via melt compounding and melt fiber spinning followed by compression molding. Film crystallinity increased with increasing CNC content indicating CNC act as nucleating agents, promoting crystallization. Furthermore, the addition of CNC increased the film storage modulus and slightly broadened the glass transition region. Composites - The mechanical properties of short glass fiber/epoxy composites containing CNCs made using sheet molding compound (SMC) manufacturing method as well as the rheological and thermomechanical properties of the CNC-epoxy composites were investigated as a function of the CNC content. CNC up to 1.4 wt% were dispersed in the epoxy to produce the resin for SMC production. The addition of CNC in the resin increased its viscosity, modulus and strength. CNC coated glass fiber/epoxy composites were investigated as a function of the CNC content on the surface of glass fibers (GF). Chopped GF rovings were coated with CNC by immersing the GF in CNC (0���5 wt%) aqueous suspensions. Single fiber fragmentation (SFF) tests showed that the interfacial shear strength (IFSS) increased by ~69% in composites produced with CNC coated GF as compared to uncoated GF, suggesting an enhancement of stress transfer across the GF/matrix interface. The unequal reactivity of the two isocyanate groups in an isophorone diisocyante (IPDI) monomer was exploited to yield modified CNCs with both urethane and isocyanate functionality. The modified CNCs showed improvements in the onset of thermal degradation by 35 °C compared to the unmodified CNCs and CNC/polyurethane composites exhibited a 200% strength increase. PLA/L-CNC (lignin coated CNC) nanocomposites were prepared by melt mixing, and the crystallization behavior of PLA was investigated using differential scanning calorimetry. The lignin-coated cellulose nanocrystals acted as a nucleating agent and significantly increased the rate of crystallization and degree of crystallinity of PLA in PLA/ L-CNC nanocomposites.

Impacts
The study of nanoscale features and materials within and extractable from wood is key to future development of new products that can revitalize the forest products sector within the US. The advantageous properties and uniformity of wood based nanomaterials allows wood to be used in the large volume and diverse markets traditionally reserved for petro chemical derived materials. Thus, the applied and fundamental research conducted on nanoscale materials is vitally important.

Publications

  • Youngblood, JP; Moon, RJ; Reising, A. 2016. Method of forming a cellulose nanocrystalline film. U.S. Patent No. 9,296,131.
  • Zhou, Y; Hernandez, C; Kippelen, B; Moon, RJ; Youngblood, JP. 2015. Recyclable Organic Solar Cells on Cellulose Nanocrystal Substrates. US. Patent No.: 9,203,030 B2.
  • Asadi, A.; Miller, M.; Moon, R.J.; Kalaitzidou, K. 2016. Improving the interfacial and mechanical properties of short glass fiber/epoxy composites by coating the glass fibers with cellulose nanocrystals. Express Polymer Letters. 10(7): 587-597.
  • Asadi, Amir; Miller, Mark; Sultana, Sanzida; Moon, Robert J.; Kalaitzidou, Kyriaki. 2016. Introducing cellulose nanocrystals in sheet molding compounds (SMC). Composites: Part A. 88: 206-215.
  • Cao, Yizheng; Zavattieri, Pablo; Youngblood, Jeffrey; Moon, Robert; Weiss, Jason. 2016. The relationship between cellulose nanocrystal dispersion and strength. Construction and Building Materials. 119: 71-79.
  • Cross, L.; Marshall, J.; Schueneman, G.; Mintz, E. 2016. Cellulose nanocrystal reinforced epoxy coatings. In: Proceedings of the 2016 Annual Meeting of the Adhesion Society. 21-24 February 2016. San Antonio, TX. 4 pp.
  • Diaz, Jairo A.; Braun, Julia L.; Moon, Robert J.; Youngblood, Jeffrey P. 2015. Iridescent cellulose nanocrystal/polyethylene oxide composite films with low coefficient of thermal expansion. International Journal of Experimental and Computational Biomechanics. 3(3): 189-199.
  • Frihart, Charles R. 2016. Cohesion and Adhesion with Proteins. 39th Annual Meeting The Adhesion Society, February 21-24, the Westin Riverwalk Hotel, San Antonio, Texas;  4 p.
  • Girouard, Natalie M.; Xu, Shanhong; Schueneman, Gregory T.; Shofner, Meisha L.; Meredith, J. Carson. 2016. Site-selective modification of cellulose nanocrystals with isophorone diisocyanate and formation of polyurethane-CNC composites. ACS Applied Materials and Interfaces. 8: 1458⿿1467.
  • Gupta, Anju; Simmons, William; Schueneman, Gregory T.; Mintz, Eric A. 2016. Lignin-coated cellulose nanocrystals as promising nucleating agent for poly(lactic acid). Journal of Thermal Analysis and Calorimetry. 9 p. DOI: 10.1007/s10973-016-5657-6.
  • Li, Mei; Tshabalala, Mandla A.; Buschle-Diller, Gisela 2016. Formulation and characterization of polysaccharide beads for controlled release of plant growth regulators. Journal of Materials Science. 51(9): 4609-4617.
  • Meree, Caitlin E.; Schueneman, Gregory T.; Meredith, J. Carson; Shofner, Meisha L. 2016. Rheological behavior of highly loaded cellulose nanocrystal/poly(vinyl alcohol) composite suspensions. Cellulose. 23(5): 3001-3012.
  • Moon, Robert J.; Schueneman, Gregory T.; Simonsen, John. 2016. Overview of cellulose nanomaterials, their capabilities and applications. The Journal of The Minerals, Metals and Materials Society (TMS). JOM. 68(9): 2383-2394.
  • Peng, Shane X.; Chang, Huibin; Kumar, Satish; Moon, Robert J.; Youngblood, Jeffrey P. 2016. A comparative guide to controlled hydrophobization of cellulose nanocrystals via surface esterification. Cellulose. 23(3): 1825-1846.
  • Sullivan, Erin; Moon, Robert; Kalaitzidou, Kyriaki. 2015. Processing and characterization of cellulose nanocrystals/polylactic acid nanocomposite films. Materials. 8(12): 8106-8116.
  • Wagner, Ryan; Moon, Robert J.; Raman, Arvind. 2016. Mechanical properties of cellulose nanomaterials studied by contact resonance atomic force microscopy. Cellulose. 23(2): 1031-1041.
  • Zelinka, Samuel L.; Ringman, Rebecka; Pilgard, Annica; Thybring, Emil Engelund; Jakes, Joseph E.; Richter, Klaus. 2016. The role of chemical transport in the brown-rot decay resistance of modified wood. International Wood Products Journal. 7(2): 66-70.
  • Zelinka, Samuel L.; Ringman, Rebecka; Pulgard, Annica; Thybring, Emil Engelund; Jakes, Joseph E.; Richter, Klaus. 2015. The role of chemical transport in the decay resistance of modified wood. In: M. Hughes, L. Rautkari, T. Uimonen, H. Militz, B. Junge (Eds.) Proceedings of the Eighth European Conference on Wood Modification. ÿlto University School of Chemical Technology; Helsinki, Finland. pp. 35-43.
  • Zheng, Rongbo; Tshabalala, Mandla A.; Du, Guanben. 2015. A combination coating of rutile TiO2 nano structures and sol-gel films to enhance weathering performance of wood. In: Paper 2 from Proceedings of the 13th Chinacoat Conference, 16-17 Novenber 2015; Shanghai, China. 11 p.
  • Zheng, Rongbo; Tshabalala, Mandla A.; Li, Qingyu; Wang, Hongyan 2016. Photocatalytic degradation of wood coated with a combination of rutile TiO2 nanostructures and low-surface free-energy materials. BioResources. 11(1): 2393-2402.


Progress 10/01/14 to 09/30/15

Outputs
OUTPUTS: Predictive Modeling: Anisotropy and temperature dependence of structural, thermodynamic and elastic properties of crystalline cellulose Iβ were computed with first-principles density functional theory. It was discovered that the thermal conductivity of native cellulose Iβ shows minimal sensitivity to temperature over the 73⿿573 K range considered in this study. Molecular dynamics simulation is commonly used to study the properties of nanocellulose-based materials at the atomic scale. Research discerned the information needed to identify the force field that will yield the most accurate results. Nanoscale Metrology: Thin-film deposition on ultra-thin substrates poses unique challenges because of the potential for a dynamic response to the film stress during deposition. It was observed that the strain in the tethered membranes increases as it is made thinner while the intrinsic steady-state stress in the deposited film is reduced. Research investigated the morphologies and supramolecular structures of CNCs from wood-pulp, cotton, bacteria, tunicate, and cladophora. Among these wood pulp based CNCs had the lowest crystallinity and highest water accessibility. Nanomaterial Composites: Research discovered a room temperature approach for growing rutile TiO2 hierarchical structures on wood surfaces. This resulted in retarded water uptake by wood, a critical property in reducing decay and infestation. The influence of cellulose nanocrystals (CNCs) addition on the performance of cement paste was investigated. Mechanical tests show an increase in the flexural strength of approximately 30% with only 0.2% volume of CNCs with respect to cement. Research on two-part epoxy systems with CNC-enhanced hardeners was conducted with three types of hardeners. Results indicate that CNC additions to pre-formulated hardeners could be an alternative approach for dispersing CNCs within epoxy matrices. Research was conducted with freeze-dried CNCs dispersed in the thermoplastic polyurethane by a solvent casting method. This study found that CNC additions resulted in wider processing temperatures for various biomedical devices while maintaining a similar stiffness, strength, and elongation. Composites of polypropylene and low density polyethylene with unmodified CNC were produced for the first time via a solventless process. The polyolefin/CNC composites had superior dispersion and property enhancements and showed that CNCs are an attractive filler for green polymer biocomposites. CNCs were incorporated into a waterborne epoxy resin following two processing protocols that vary by order of addition. The implication of these mixing method dependent structural changes in polymer network formation results in an extension of the epoxy and cross-linker mixture's pot life by three orders of magnitude. Research achieved a multiscale description of the thermal conductivity of CNCs from single CNCs to their organized nanostructured films. The low interfacial barrier to heat transport found for CNCs, and their versatile alignment capabilities offer unique opportunities in thermal conductivity control. Studies investigated the performance and characterization of top-gate organic field-effect transistors fabricated on recyclable CNC/glycerol substrates. These devices exhibit low operating voltage, low threshold voltage, and operational stability in ambient conditions. Dry spun cellulose acetate fibers were researched using CNCs as reinforcements. It was shown that the CNC alignment directly correlates to the mechanical properties of the composite. Maximum improvements of 137% in tensile strength and 637% in elastic modulus were achieved.

Impacts
This research improved our understanding of the nanostructures obtainable from wood and how these new materials can spawn the next generation for high technology forest products. The research in this problem area contributes to predictions of fundamental properties of cellulose and cellulosic nanomaterials and how this is competently accomplished in silico, how mechanical property measurements can be made at the nano to microscale, the morphological and physical variation of cellulosic nanomaterials from various sources, modification of wood cell walls with nanomaterials for enhance moisture resistance, the next generation of biobased adhesives, and composites with cellulosic nanomaterials that offer clear evidence of viable market opportunities for wood that never existed before.

Publications

  • Agarwal, Umesh P.; Reiner, Richard S.; Hunt, Christopher G.; Catchmark, Jeffery; Foster, E. Johan; Isogai, Akira 2015. Comparison of Cellulose Supramolecular Structures Between Nanocrystals of Different Origins. Proceedings of the 18th ISWFPC (International Symposium on Wood, Fiber, and Pulping Chemistry) held in Vienna (Sept 9 -11, 2015). 2015; pp. 6-9.
  • Cao, Yizheng; Zavaterri, Pablo; Youngblood, Jeff; Moon, Robert; Weiss, Jason 2015. The influence of cellulose nanocrystal additions on the performance of cement paste. CEMENT AND CONCRETE COMPOSITES, Volume 56, 2015; pp. 73-83.
  • Chen, Si; Schueneman, Greg; Pipes, R. Byron; Youngblood, Jeffrey; Moon, Robert J. 2014. Effects of Crystal Orientation on Cellulose Nanocrystals-Cellulose Acetate Nanocomposite Fibers Prepared by Dry Spinning. Biomacromolecules, Volume 15, 2014; pp. 3827-3835.
  • Clausen, Anna M.; Paskiewicz, Deborah M.; Sadeghirad, Alireza; Jakes, Joseph; Savage, Donald E.; Stone, Donald S.; Liu, Feng; Lagally, Max G. 2014. Silicon nanomembranes as a means to evaluate stress evolution in deposited thin films. Extreme Mechanics Letters. 1: 9-16.
  • Diaz, Jairo A.; Ye, Zhijiang; Wu, Xiawa; Moore, Arden L.; Moon, Robert J.; Martini, Ashlie; Boday, Dylan J.; Youngblood, Jeffrey P. 2014. Thermal Conductivity in Nanostructured Films: From Single Cellulose Nanocrystals to Bulk Films. Biomacromolecules, Volume 15, 2014; pp. 4096-4101.
  • Dri, Fernando L.; Wu, Xiawa; Moon, Robert J.; Martini, Ashlie; Zavattieri, Pablo D. 2015. Evaluation of reactive force fields for prediction of the thermo-mechanical properties of cellulose Iâ. Computational Materials Science. 109: 330-340.
  • Dri,; Fernando L.; Shang, ShunLi; Hector Jr., Louis G.; Saxe, Paul; Liu, Zi-Kui; Moon, Robert J.; Zavattieri, Pablo D. 2014. Anisotropy and temperature dependence of structural, thermodynamic, and elastic properties of crystalline cellulose Iβ: a first-principles investigation. Modelling Simul. Mater. Sci. Eng. Volume 22, 2014; 28 p.
  • Frihart, Charles R.; Lorenz, Linda 2013. Protein Modifiers Generally Provide Limited Improvement in Wood Bond Strength of Soy Flour Adhesives. Forest Prod. J. Volume 63, Number 3/4: 2013; pp. 138⿿142.
  • Girouard, Natalie; Schueneman, Gregory T.; Shofner, Meisha L.; Meredith, J. Carson 2015. Exploiting colloidal interfaces to increase dispersion, performance, and pot-life in cellulose nanocrystal/waterborne epoxy composites. Polymer. 68: 111-121.
  • Iyer, Krishnan A.; Schueneman, Gregory T.; Torkelson, John M. 2015. Cellulose nanocrystal/polyolefin biocomposites prepared by solid-state shear pulverization: Superior dispersion leading to synergistic property enhancements. Polymer, Volume 56, 2015; pp. 464-475.
  • Liu, Jen-Chieh; Martin, Darren J.; Moon, Robert J.; Youngblood, Jeffrey P. 2015. Enhanced thermal stability of biomedical thermoplastic polyurethane with the addition of cellulose nanocrystals. Journal of Applied Polymer Science. Volume 132, Number 22, 2015; 8 p.
  • Moon, Robert J.; Pöhler, Tiina; Tammelin, Tekla 2014. Chapter 11: Microscopic Characterization of Nanofibers and Nanocrystals. In: Materials and Energy - Volume 5, Handbook of Green Materials, Chapter 11, 2014; pp. 159-180.
  • Oksman, Kristiina; Moon, Robert J. 2014. Chapter 7: Characterization of Nanocomposites Structure. In: Materials and Energy - Volume 5 ; Handbook of Green Materials Bionanocomposites: Processing, characterization and properties; 2014; pp. 89-105.
  • Peng, Shane X.; Moon, Robert J.; Youngblood, Jeffrey P. 2014. Design and characterization of cellulose nanocrystal-enhanced epoxy hardeners. Green Materials. 2(4): 193-205.
  • Wang, Cheng-Yin; Fuentes-Hernandez, Canek; Liu, Jen-Chieh; Dindar, Amir; Choi, Sangmoo; Youngblood, Jeffrey P.; Moon, Robert J.; Kippelen, Bernard 2015. Stable Low-Voltage Operation Top-Gate Organic Field-Effect Transistors on Cellulose Nanocrystal Substrates. ACS Applied Materials & Interfaces. 7(8): 4804-4808.
  • Xu, Shanhong; Girouard, Natalie; Cross, Lionel; Mintz, Eric; Schueneman, Greg; Shofner, Meisha L.; Meredith, Carson 2013. Chapter 1.4: Mechanical and Thermal Property Enhancement in Cellulose Nanocrystal/Waterborne Epoxy Composites. In: Production and applications of Cellulose nanomaterials, Chapter 1.4, TAPPI Press, 2013; pp. 97-98.
  • Zheng, Rongbo; Tshabalala, Mandla A.; Li, Qingyu; Wang, Hongyan 2015. Construction of hydrophobic wood surfaces by room temperature deposition of rutile (TiO2) nanostructures. Applied Surface Science, Volume 328, 2015; pp. 453-458.


Progress 10/01/13 to 09/30/14

Outputs
OUTPUTS: Predictive Modeling: Atomistic simulations yielded predictions of the variations of the elastic properties and fracture properties of crystalline cellulose Iβ with crystallographic direction revealing the extreme anisotropies of these mechanical properties. The results agreed well with experimental values. The reinforcement potential of cellulose nanomaterials (CNs) on idealized 2-dimentional micron sized fiber network structure was investigated where a hierarchical modeling approach was used to account for the contribution of different size scale structures on the macroscopic properties of the network. The extent to which CNC-epoxy coating can stiffen a fiber element was dependent on the CNC volume fraction, CNC-epoxy layer thickness, CNC alignment, CNC aspect ratio, and the original stiffness of the fiber element. Nanoscale Metrology: Nanoindentation methods were developed and implemented to assess the effects of humidity on the mechanics of SiCOH thin films deposited on silicon wafer substrates. It was found that humidity affected the mechanical properties of the films, and the fracture behavior between the thin film and substrate. In FY13 a new artifact free method was developed to measure the coefficient of thermal expansion (CTE) of CNC films. The approach was expanded to test other polymer films using digital image correlation (DIC) in which the speckle marker patterns needed for DIC to track strain, were obtained within the polymer materials via textures highlighted by contrast enhanced optical microscopy modes. Nanomaterial Composites: Although the most abundant source of lignin is from the Kraft pulping process, it is not widely used due the expense of separating it from the other materials. However, a new process, Biochoice⿢ carbon dioxide precipitation of lignin, has been commercialized by Domtar as their LignoBoost⿢ lignin. This material has not been well characterized; therefore, this research evaluated the physical properties and chemical composition of this lignin. 4707 scientists and collaborative researchers demonstrated the efficient polymer solar cells fabricated on optically transparent cellulose nanocrystal (CNC) substrates. In FY13 the solar cells reached a power conversion efficiency of 2.7%. In FY14 a new organic solar cell device structure that was deposited onto cellulose nanocrystal (CNC) films as the base substrate and provided higher efficiencies (4.0%), a new record for solar cells on cellulose based substrates. The reinforcement potential of cellulose nanofibrils (CNF) and CNC films laminated onto wood flakes (WF) was investigated. The influence of CN film lamination, relative humidity, heat treatment, and anisotropic properties of WF on the CN-WF laminate tensile properties (elastic modulus, ultimate tensile strength, and strain to failure). CNC-based composites with a waterborne epoxy resin matrix were prepared and characterized to determine morphology, water content, and thermal and mechanical properties. While some CNC aggregation was observed, significant increases in modulus, tensile strength and Tg were observed. Defect-free electrospun fibers were produced from aqueous dispersions of lignin, poly(vinyl alcohol) (PVA), and CNCs, which were used as reinforcing nanoparticles. After addition of 5 wt % CNCs, both the DMA and nanoindentation elastic modulus remained constant, while after addition of 15 wt % CNCs, both increased substantially. An indentation size effect was observed in the nanoindentation hardness, and the results provided insight into the effect of addition of CNCs on the microphysical processes controlling the yield behavior in the composites.

Impacts
Successful computer simulation of CNC⿿s provides a methodology for predicting properties of composites, films, and fibers made with CNC⿿s. This could save time and resources by informing researches about what systems will provide the most promising performance. The review book provides a comprehensive source of current research on nanocellulose and its applications. Industrial interest and research collaboration is anticipated to be greatly enhanced due to its assembly and publication. Research on zinc ⿿ surfactant films provides a further understanding of the growth and stability of derived nanomembranes, as well as advisory insight for the further development on solution-based synthesis of free-standing, single-crystalline 2D nanostructures. The new method of CTE measurement allows artifact free characterization of a key performance metric for composites. This will greatly aid in the demonstration of the benefits of incorporating CNC⿿s into polymer composites that have detrimentally high CTE values for many applications. Research into the methods used to dry CNC and CNF aqueous solutions provide key guidance that for best redispersion of the particles it will be significantly more successful if supercritical drying was employed and freeze drying was avoided. Studies of doping of CNF films revealed that the Ag-TiO2-CNF film has potential for degradation of organic molecules in natural water sources a valuable and highly sought after attribute for remediation of waste and purification of drinking water. Nanoindentation protocols are now established to assess hygromechanical properties of from small volumes of materials, including CNC-based films and wood cell walls. Composite films and fibers made with CNCs demonstrate that the high modulus observed at the nanoscale transfers to successful reinforcement of polymers at the macroscale. Such findings provide evidence of CNCs commercial viability. By demonstrating how the new artifact free DIC method can be used to determine CTEs for other polymer material systems it expands the impact of this technique to a much broader material base as well as CN-polymer composite systems. These results of composite studies with CNCs and WB epoxy provide evidence that CNCs can improve thermomechanical performance of polymers and that they are promising as reinforcing fillers in structural materials and coatings. Efficient and easily recyclable organic solar cells on CNC substrates are expected to be an attractive technology for sustainable, scalable, and environmentally-friendly energy production.

Publications

  • Ago, Mariko; Jakes, Joseph E.; Rojas, Orlando J. 2013. Thermomechanical Properties of Lignin-Based Electrospun Nanofibers and Films Reinforced with Cellulose Nanocrystals: A Dynamic Mechanical and Nanoindentation Study. ACS Appl. Mater. Interfaces, Volume 5, 2013; pp. 11768-11776.
  • Guo, Xiangyu; Jakes, Joseph E.; Banna, Samer; Nishi, Yoshio; Shohet, J. Leon 2014. Effect of water uptake on the fracture behavior of low-k organosilicate glass. Journal of Vacuum Science & Technology A 32, 2014; pp. 031512 1-8. doi: 10.1116/1.4871680; 2014
  • Liu, Jen-Chieh; Moon, Robert J.; Rudie, Alan; Youngblood, Jeffrey P. 2014. Mechanical performance of cellulose nanofibril film-wood flake laminate. Holzforschung 2014; Volume 68, Number 3, 2014; pp. 283⿿290.
  • Shohet, J.L.; Lin, Q.; King, S.W.; Ren, H.; Banna, S.; Jakes, J.E.; Agasie, R.J.; Naik, M.; Nishi, Y.; Nichols, M.T.; Mavrakakis, K.; Hsu, K.; Guo, X.; Pei, D.; Li, W.; Choudhury, F.; Zheng, H. 2014. Dielectric Damage. ECS Transactions, Volume 60, Number 1, 2014; pp. 733-738.
  • Chen, Yao; Stark, Nicole M.; Cai, Zhiyong; Frihart, Charles R.; Lorenz, Linda F.; Ibach, Rebecca E. 2014. Chemical Modification of Kraft Lignin: Effect on Chemical and Thermal Properties. BioResources, Volume 9, Number 3, 2047; pp. 5488-5500.
  • Diaz, Jairo A.; Moon, Robert J.; Youngblood, Jeffrey P. 2014. Contrast Enhanced Microscopy Digital Image Correlation: A General Method to Contact-Free Coefficient of Thermal Expansion Measurement of Polymer Films. ACS Appl. Mater. Interfaces Volume 6, 2014; pp. 4856-4863.
  • Dri, Fernando L.; Hector, Louis G. Jr.; Moon, Robert J.; Zavattieri, Pablo D. 2013. Anisotropy of the elastic properties of crystalline cellulose Iÿ from first principles density functional theory with Van der Waals interactions. Cellulose, Volume 20, 2013; pp. 2703-2718.
  • Goodsell, Johnathan E.; Moon, Robert J.; Huizar, Alionso; Pipes, R. Byron 2014. A strategy for prediction of the elastic properties of epoxy-cellulose nanocrystal-reinforced fiber networks. Nordic Pulp & Paper Research Journal Volume 29, Number 1, 2014; pp. 85-94.
  • Guo, X.; Jakes, J.E.; Banna, S.; Nishi, Y.; Shohet, J.L. 2014. Effects of plasma and vacuum-ultraviolet exposure on the mechanical properties of low-k porous organosilicate glass. Journal of Applied Physics 116, 2014; pp. 044103; 1-9. doi: 10.1063/1.4891501; 2014
  • Guo, X.; Jakes, J.E.; Nichols, M.T.; Banna, S.; Nishi, Y.; Shohet, J.L. 2013. The effect of water uptake on the mechanical properties of low-k organosilica glass. J. Appl. Phys. Volume 114, 2013; pp. 084103-1 to 084103-11.
  • Wu, Xiawa; Moon, Robert J.; Martini, Ashlie 2013. Atomistic Simulation of Frictional Sliding Between Cellulose Iÿ Nanocrystals. Tribol Lett Volume 52, 2013; pp. 395-405.
  • Wu, Xiawa; Moon, Robert J.; Martini, Ashlie 2014. Tensile strength of Iÿ crystalline cellulose predicted by molecular dynamics simulation. Cellulose Volume 21 2014; pp. 2233-2245.
  • Xu, Shanhong; Girouard, Natalie; Schueneman, Gregory; Shofner, Meisha L.; Meredith, J. Carson 2013. Mechanical and thermal properties of waterborne epoxy composites containing cellulose nanocrystals. Polymer, Volume 54, 2013; pp. 6589-6598.
  • Zhou, Yinhua; Khan, Talha M.; Liu, Jen-Chieh; Fuentes-Hernandez, Canek; Shim, Jae Won; Najafabadi, Ehsan; Youngblood, Jeffrey P.; Moon, Robert J.; Kippelen, Bernard 2014. Efficient recyclable organic solar cells on cellulose nanocrystal substrates with a conducting polymer top electrode deposited by film-transfer lamination. ORGANIC ELECTRONICS, Volume 15, 2014; pp. 661-666.


Progress 10/01/12 to 09/30/13

Outputs
OUTPUTS: A book was published, co-edited by 4707 scientist, comprising of a summary of current research in the areas of nanocellulose fundamental science to applications. Chapters published in this book by 4707 authors included the topics of general review, cement, wood flake, and epoxy composites, surface functionalization with metal, metal oxide and semiconducting particles and possible applications thereof, thermal properties, AFM characterization, and drying of aqueous suspensions. Predictive Modeling: Atomistic simulations yielded predictions of the elastic modulus of Cellulose I in the axial and transverse directions based on a nanoscale indentation. The simulation used a reactive force field to explicitly describe hydrogen bonds, coulombic and van der Walls interactions. This allowed the inter- and intra- molecular forces to be analyzed. The results agreed well with experimental values. Targeted Surface Functionalization: Research into the methods used to dry CNC and CNF aqueous solutions were undertaken with air-drying, freeze-drying, spray-drying, and supercritical-drying. The surface energies of the resultant particles were determined via reverse phase gas chromatography. Supercritical drying resulted in the highest surface energy by almost 100% over the other methods. Freeze drying, the most commonly employed method, resulted in the lowest. The research indicates that for redispersion of the particles it will be significantly more successful if supercritical drying was employed and freeze drying was avoided. Nanoscale Metrology: Nanoindentation revealed that a free standing film composed of 2D zinc dodecylsulfate nanostructures have similar mechanical properties as a structural polymer. A new method was developed to measure the coefficient of thermal expansion (CTE) of CNC films as cast and with shear alignment. The new method is non-contact allowing artifact free measurements. The as cast (isotropic) films had a uniform CTE of 25 ppm regardless of sampling direction. With alignment the CTE in the shear direction approached 9 ppm and the out of shear plane direction had a CTE of 158 ppm. Computer modeling agreed with these results and allowed the identification of inter and intracrystal responses to heating. Nanomaterial Composites: 4707 scientists and collaborative researchers demonstrated the first efficient polymer solar cells fabricated on optically transparent cellulose nanocrystal (CNC) substrates. The solar cells reached a power conversion efficiency of 2.7% a new record for flexible solar cells. It was also demonstrated that these solar cells can be easily separated and recycled into their major components using low-energy processes at room temperature, opening the door for a truly recyclable solar cell technology. Efficient and easily recyclable organic solar cells on CNC substrates are expected to be an attractive technology for sustainable, scalable, and environmentally-friendly energy production. Defect-free electrospun fiber mats and spin coated films obtained from aqueous dispersions of lignin, polyvinyl alcohol (PVA), and CNC. Using nanoscale thermal analyses, the continuous phase was determined to be lignin-rich and the discontinuous phase had a lignin/PVA dispersion until. Importantly, the size of the phase separated domains was reduced by the addition of CNCs and the mats became super hydrophilic.

Impacts
TiO2-CNF composite films populated with gold and silver nanoclusters were fabricated and evaluated for photocatalytic activity under UV light and their potential to remove organic compounds from water. TiO2 ⿿CNF films were shown to be strongly photocatalytic in UV light and those films additionally treated with gold and silver demonstrated enhanced activity in visible light while increasing robustness of the film. The Ag-TiO2-CNF film was shown to have potential for degradation of organic molecules in natural water sources. CNC ⿿ epoxy composites were fabricated via addition to waterborne and solventborne resin systems. CNC⿿s were dispersed in the waterborne system with low shear mixing resulting in continuous and phase separated domains of CNC's. The mechanical reinforcement was significant yet much lower than previously reported for a fully dispersed system. Here as CNC⿿s loading increased the Tg of the composite increased. This is contrary to the prior work on fully dispersed systems. The solventborne epoxy-CNC nanocomposite exhibited full dispersion and significant increases in stiffness. Coatings comprising of waterborne epoxy reinforced with up to 10% CNC's were applied to steel substrates, cured and then subject to atmospheric pressure discharge plasma treatment. Post treatment the water wettability and peel strength of the surfaces were greatly improved. Synchrotron based FTIR chemical imaging was used to map out the spatial distribution of the phases making up a poly(acrylic acid), poly(vinyl alcohol) and CNC composite. PAA was found to have migrated out of the PVOH matrix and concentrated in CNC rich domains thereby preventing the desired cross-linking reaction between PAA and PVOH. Successful computer simulation of CNC's provides a methodology for predicting properties of composites, films, and fibers made with CNC's. This could save time and resources by informing researches about what systems will provide the most promising performance. The review book provides a comprehensive source of current research on nanocellulose and its applications. Industrial interest and research collaboration is anticipated to be greatly enhanced due to its assembly and publication. Research on zinc ⿿ surfactant films provides a further understanding of the growth and stability of derived nanomembranes, as well as advisory insight for the further development on solution-based synthesis of free-standing, single-crystalline 2D nanostructures. The new method of CTE measurement allows artifact free characterization of a key performance metric for composites. This will greatly aid in the demonstration of the benefits of incorporating CNC's into polymer composites that have detrimentally high CTE values for many applications. Research into the methods used to dry CNC and CNF aqueous solutions provide key guidance that for best redispersion of the particles it will be significantly more successful if supercritical drying was employed and freeze drying was avoided. Studies of doping of CNF films revealed that the Ag-TiO2-CNF film has potential for degradation of organic molecules in natural water sources a valuable and highly sought after attribute for remediation of waste and purification of drinking water.

Publications

  • Ago, Mariko; Jakes, Joseph E.; Johansson, Leena-Sisko; Park, Sunkyu; Rojas, Orlando J. 2012. Interfacial properties of lignin-based electrospun nanofibers and films reinforced with cellulose nanocrystals. ACS Applied Materials and Interfaces. 4: 6849-6856.
  • Cao, Yizheng; Weiss, W. Jason; Youngblood, Jeffrey; Moon, Robert; Zavattieri, Pablo. 2013. Performance-enhanced cementitious materials by cellulose nanocrystal additions. In: Postek, Michael T.; Moon, Robert J.; Rudie, Alan W.; Bilodeau, Michael A., eds. Production and Applications of Cellulose Nanomaterials. Peachtree Corners, GA: TAPPI Press. pp. 135-136, Chapter 1.4. ISBN: 978-1-59510-224-9.
  • Clemons, Craig; Sedlmair, Julia; Illman, Barbara; Ibach, Rebecca; Hirschmugl, Carol. 2013. Chemically imaging the effects of the addition of nanofibrillated cellulose on the distribution of poly(acrylic acid) in poly(vinyl alcohol). Polymer. 54(8): 2058-2061.
  • Committee on Assessing the Importance and Impact of Glycomics and Glycosciences. 2012. Transforming glycoscience: A roadmap for the future. National Academy of Sciences. Online publication. 209 p.
  • Cross, L.; Schueneman, G.; Mintz, E.; Xu, Shanhong; Girouard, Natalie; Shofner, Meisha; Meredith, Carson. 2013. Nanocellulose reinforced epoxy elastomer. Published online in: Proceedings of the 36th annual meeting of The Adhesion Society. 2013 March 3-6; Daytona Beach, FL. Blacksburg, VA: The Adhesion Society. 3 p.
  • Diaz, Jairo A.; Wu, Xiawa; Martini, Ashlie; Youngblood, Jeffrey P.; Moon, Robert J. 2013. Thermal expansion of self-organized and shear-oriented cellulose nanocrystal films. Biomacromolecules. 14: 2900-2908.
  • Diaz, Jairo A.; Youngblood, Jeffrey P.; Moon, Robert J. 2013. Effect of cellulose nanocrystal alignment on thermo-mechanical response. In: Postek, Michael T.; Moon, Robert J.; Rudie, Alan W.; Bilodeau, Michael A., eds. Production and Applications of Cellulose Nanomaterials. Peachtree Corners, GA: TAPPI Press. pp. 69-70, Chapter 1.3. ISBN: 978-1-59510-224-9.
  • Dri, Fernando L.; Moon, Robert J.; Zavattieri, Pablo D. 2013. Multiscale modeling of the hierarchical structure of cellulose nanocrystals. In: Postek, Michael T.; Moon, Robert J.; Rudie, Alan W.; Bilodeau, Michael A., eds. Production and Applications of Cellulose Nanomaterials. Peachtree Corners, GA: TAPPI Press. pp. 139-141, Chapter 1.5. ISBN: 978-1-59510-224-9.
  • Liu, Jen-Chieh; Moon, Robert J.; Youngblood, Jeffrey P. 2013. Mechanical properties of cellulose nanofibril-wood flake laminate. In: Postek, Michael T.; Moon, Robert J.; Rudie, Alan W.; Bilodeau, Michael A., eds. Production and Applications of Cellulose Nanomaterials. Peachtree Corners, GA: TAPPI Press. pp. 287-288, Chapter 1.3. ISBN: 978-1-59510-224-9.
  • Moon, Robert; Beck, Stephanie; Rudie, Alan. 2013. Cellulose nanocrystals - A material with unique properties and many potential applications. In: Postek, Michael T.; Moon, Robert J.; Rudie, Alan W.; Bilodeau, Michael A., eds. Production and Applications of Cellulose Nanomaterials. Peachtree Corners, GA: TAPPI Press. pp. 9-12, Chapter 1. ISBN: 978-1-59510-224-9.
  • Padalkar, Sonal; Moon, Robert; Stanciu, Lia. 2013. Cellulose nanocrystals: Novel templates for synthesis of nanostructures. In: Postek, Michael T.; Moon, Robert J.; Rudie, Alan W.; Bilodeau, Michael A., eds. Production and Applications of Cellulose Nanomaterials. Peachtree Corners, GA: TAPPI Press. pp. 159-160, Chapter 1.6. ISBN: 978-1-59510-224-9.
  • Peng, Yucheng; Gardner, Douglas J.; Han, Yousoo; Cai, Zhiyong; Tshabalala, Mandla A. 2013. Influence of drying method on the surface energy of cellulose nanofibrils determined by inverse gas chromatography. Journal of Colloid and Interface Science. 405: 85-95.
  • Peng, Yucheng; Gardner, Douglas J.; Han, Yousoo; Kiziltas, Alper; Cai, Zhiyong; Tshabalala, Mandla A. 2013. Influence of drying method on the material properties of nanocellulose I: thermostability and crystallinity. Cellulose. 20(5): 2379-2392.
  • Reising, Alexander B.; Moon, Robert J.; Youngblood, Jeffrey P. 2012. Effect of particle alignment on mechanical properties of neat cellulose nanocrystal films. Journal of Science and Technology for Forest Products and Processes. 2(6): 32-41.
  • Peng, Yucheng; Gardner, Douglas J.; Han, Yousoo; Cai, Zhiyong; Tshabalala, Mandla A. 2013. Drying cellulose nanocrystal suspensions. In: Postek, Michael T.; Moon, Robert J.; Rudie, Alan W.; Bilodeau, Michael A., eds. Production and Applications of Cellulose Nanomaterials. Peachtree Corners, GA: TAPPI Press. pp. 31-33, Chapter 1.1. ISBN: 978-1-59510-224-9.
  • Peng, Yucheng; Gardner, Douglas J.; Han, Yousoo; Cai, Zhiyong; Tshabalala, Mandla A. 2013. Drying cellulose nanofibril suspensions. In: Postek, Michael T.; Moon, Robert J.; Rudie, Alan W.; Bilodeau, Michael A., eds. Production and Applications of Cellulose Nanomaterials. Peachtree Corners, GA: TAPPI Press. pp. 215-217, Chapter 2.1. ISBN: 978-1-59510-224-9.
  • Snyder, Alexandra; Bo, Zhenyu; Moon, Robert J.; Stanciu, Lia. 2013. Surface functionalization of TiO2-CNF films with Au and Ag nanoclusters for visible light photocatalysis. In: Postek, Michael T.; Moon, Robert J.; Rudie, Alan W.; Bilodeau, Michael A., eds. Production and Applications of Cellulose Nanomaterials. Peachtree Corners, GA: TAPPI Press. pp. 265-266, Chapter 2.3. ISBN: 978-1-59510-224-9.
  • Snyder, Alexandra; Bo, Zhenyu; Moon, Robert; Rochet, Jean-Christophe; Stanciu, Lia. 2013. Reusable photocatalytic titanium dioxide-cellulose nanofiber films. Journal of Colloid and Interface Science. 399: 92-98.
  • Wagner, Ryan; Raman, Arvind; Moon, Robert. 2013. Atomic force microscope characterization of cellulose nanocrystal transverse properties. In: Postek, Michael T.; Moon, Robert J.; Rudie, Alan W.; Bilodeau, Michael A., eds. Production and Applications of Cellulose Nanomaterials. Peachtree Corners, GA: TAPPI Press. pp. 39-40, Chapter 1.1. ISBN: 978-1-59510-224-9.
  • Wang, Fei; Jakes, Joseph E.; Geng, Dalong; Wang, Xudong. 2013. Spontaneous phase transformation and exfoliation of rectangular single-crystal zinc hydroxy dodecylsulfate nanomembranes. ACSNANO. 7(7): 6007-6016.
  • Wolf, Rory A.; Girouard, Natalie; Xu, Shanhong; Meredith, J. Carson; Shofner, Meisha L.; Cross, Lionel; Mintz, Eric; Schueneman, Gregory T. 2013. Adhesion improvements of nanocellulose composite interfaces. Plastics Engineering Magazine. pp. 32-37.
  • Wu, Xiawa; Moon, Robert J.; Martini, Ashlie. 2013. Atomistic simulation of nanoscale indentation on cellulose nanocrystals. In: Postek, Michael T.; Moon, Robert J.; Rudie, Alan W.; Bilodeau, Michael A., eds. Production and Applications of Cellulose Nanomaterials. Peachtree Corners, GA: TAPPI Press. pp. 143-144, Chapter 1.5. ISBN: 978-1-59510-224-9.
  • Wu, Xiawa; Moon, Robert J.; Martini, Ashlie. 2013. Crystalline cellulose elastic modulus predicted by atomistic models of uniform deformation and nanoscale indentation. Cellulose. 20: 43-55.
  • Xu, Shanhong; Girouard, Natalie; Cross, Lionel; Mintz, Eric; Schueneman, Greg; Shofner, Meisha; Meredith, Carson. 2013. Mechanical and thermal property enhancement in cellulose canocrystal/waterborne epoxy composites. Published online in: Proceedings of the 36th annual meeting of The Adhesion Society. 2013 March 3-6; Daytona Beach, FL. Blacksburg, VA: The Adhesion Society. 3 p.
  • Zhou, Yinhua; Fuentes-Hernandez, Canek; Khan, Talha M.; Liu, Jen-Chieh; Hsu, James; Shim, Jae Won; Dindar, Amir; Youngblood, Jeffrey P.; Moon, Robert J.; Kippelen, Bernard. 2013. Cellulose nanocrystal substrates for recyclable printed electronics. In: Postek, Michael T.; Moon, Robert J.; Rudie, Alan W.; Bilodeau, Michael A., eds. Production and Applications of Cellulose Nanomaterials. Peachtree Corners, GA: TAPPI Press. pp. 167-168, Chapter 1.6. ISBN: 978-1-59510-224-9.
  • Zhou, Yinhua; Fuentes-Hernandez, Canek; Khan, Talha M.; Liu, Jen-Chieh; Hsu, James; Shim, Jae Won; Dindar, Amir; Youngblood, Jeffrey P.; Moon, Robert J.; Kippelen, Bernard. 2013. Recyclable organic solar cells on cellulose nanocrystal substrates. Scientific Reports. 3(1536): 5 p.