Progress 09/01/05 to 06/30/10
Outputs
OUTPUTS: In the life of this project, we have 1). made a significant achievement in publications, including 2 book chapters, 16 referred journal articles, 3 proceeding papers and 17 abstracts; 2).trained a significant number of our future work forces, including 4 graduate students, two post-doctoral research associates and 2 visiting scholars; 3). shared our results by giving more than 20 presentations in the national and international conferences; 4). Our research results have been recognized by colleague around the world. Sandeep Sudhakaran Nair, a Ph. D. graduate student has been awarded the first place in the 2010 Student Poster Competition at the 64th International Convention of the Forest Products Society. His poster title was Influence of fiber/matrix nano-interphase on the mechanical properties of natural fiber reinforced polymer composites. Our poster presentation, titled as Evaluation of Interphase Properties in Fiber Reinforced Polymer Composite Using Contact Resonance Force Microscopy, was awarded the second place in the Poster competition at the 2008 Annual Meeting of Society of Wood Science and Technology at Chile. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
This work has developed an improved understanding of interphase in fiber reinforced polymer composite under nano or sub-macro scale. The new knowledge is useful for any type of fibers, such as natural cellulose fiber, glass fiber, carbon fiber, carbon nanofiber et al. The interphase in fiber-reinforced composite materials is very important, and our better understanding of the properties and characteristics of interphase will be helpful to evaluate the overall properties of composite materials. Critical and essential information about interphase, obtained in this project, will be very useful for optimum design of final natural fiber reinforced polymer composites (NFRPC) and for the whole area of composites from renewable resources. This research would help the introduction of natural fibers into new applications in polymer composites.
Publications
- Wang, S., S-H, Lee and Q. Cheng. 2010. Book Chapter 19- Mechanical properties of cellulosic materials at micro- and nanoscale levels. In the book "Cellulose: Structure and Properties, Derivatives and Industrial Uses". Nova Publishers, USA (ISBN: 978-1-60876-388-7). P. 459-500.
- Wang, S. 2009. Book Chapter 12- Evaluation of transgenic wood for wood productivity and quality. In the book "Biosystem Engineering". McGraw Hill Publishers, USA (ISBN: 978-0-07-160628-8). P. 347-366.
- Wu, Y., S. Wang, D. Zhou, C. Xing, Y. Zhang, Z. Cai. 2010. Evaluation of nanomechanical properties of agricultural crops by nanoindentation. Bioresource Technology 101(8):2867-2871.
- Nair, S.S., S. Wang, D. Hurley. 2010. Nanoscale characterization of natural fiber and its composite using contact resonance force microscopy. Composites Part A 41: 624-631.
- Wu, Y., D. Zhou, S. Wang, C. Xing, Y. Zhang. 2010. Nano-mechanical properties of the cell wall of crop straws. Scientia Silvae Sinicae 46(9): 140-143.
- X. Zhang, Q. Zhao, S. Wang, R. Trejo, E. Lara-Curzio, G. Du. 2010. Characterizing strength and fracture of wood cell wall through uniaxial micro-compression test. Composites Part A 41: 632-638.
- Wang S., S.S. Nair, D. Hurley, S-H. Lee. 2010. Characterizing Interphase Properties in Fiber Reinforced Polymer Composite with Advanced AFM Based Tools. Advanced Materials Research 123-125: 403-406.
- Wang, S, S.S. Nair, D. Hurley, S.H. Lee. 2010. Advanced AFM-based techniques for characterizing composite interphases. 2010 International Conference on Nanotechnology for the Forest Products Industry, Espoo, Finland. 27-29 September.
- S.S. Nair, S. Wang, D. Hurley. 2010. Nanoscale Characterization of Interphase and their Impact on the Performance of Natural Fiber Reinforced Polymer Composites. 64th International Convention of Forest Products Society, June 20-22, Madison, Wisconsin. P. 43.
- Meng Y., S. Wang, Z. Cai. 2010. Effect of Moisture Content on the Nanomechanical Properties of Wood Cell Wall via Nanoindentation. 64th International Convention of Forest Products Society, June 20-22, Madison, Wisconsin. P. 77.
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Progress 09/01/08 to 08/31/09
Outputs
OUTPUTS: In this report period, we have 1). Directly visualized interfacial zone in regenerated cellulose fiber-reinforced polypropylene composite by phase and thermal conductivity contrast imaging using AFM. It showed that AFM based tools are very useful to characterize the interphase down to 20 nm; 2). Prepared regenerated cellulose fiber-reinforced polypropylene composite by extrution; We will fully investigate the correlation between macro properties of composites and interphase properties; 3). Investigated the mechanical properties of ten hardwood species, which provided basic information about reinforcement potential to use different wood species in polymer composites. Two manuscripts have been submitted into refereed journals for possible publication during this reporting period. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
This work has developed an improved understanding of interphase in fiber reinforced polymer composite under nano or sub-macro scale. The knowledge is useful for any type of fibers, such as natural cellulose fiber, glass fiber, carbon fiber, carbon nanofiber et al.
Publications
- Wu, Y., D. Zhou, S. Wang, Y. Zhang. 2009. Polypropylene composites reinforced with rice straw micro/nano fibrils isolated by high intensity ultrasonication. BioResources, 4(4): 1487-1497.
- Wu, Y., D. Zhou, S. Wang, Y. Zhang. 2009. Relationship between wood microfibril angle, density and modulus. Journal of Nanjing Forestry University 33(4):113-116.
- Wu, Y., S. Wang, D. Zhou, Y. Zhang, C. Xing, S-H Lee, G. Du. 2009. Nano-mechanics and its applications in cellulose materials. Proceedings of the 16th International symposium on Nondestructive Testing and Evaluation of Wood. October 12-14, Beijing, China. Pp. 195-201.
- Wang, S., C. Xing, Y. Wu, X. Zhang, Q. Cheng and Y. Meng. 2009. Nano-mechanics: theory, methodology and application in wood science. COST Action FP0802 Workshop "Experimental and Computational methods in wood micromechanics, May 11-13, Vienna, Austria. P. 91.
- Lee, S., S. Wang, T. Endo, N.H. Kim. 2009. Visualization of interfacial zone in regenerated cellulose fiber-reinforced polypropylene composite by phase and thermal conductivity contrast imaging using AFM. Holzforschung 63: 240-247.
- Wu, Y., S. Wang, D. Zhou, C. Xing, Y. Zhang. 2009. Use of nanoindentation and SilviScan to determine mechanical properties of ten hardwood species. Wood and Fiber Science 41(1): 64-73.
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Progress 09/01/07 to 08/31/08
Outputs
OUTPUTS: In this report period, we have developed another partner from the National Institute of Standard & Technology to conduct this project using some of their new techniques and facility which were not proposed in our proposal. The influence of different treatments on interphase was analyzed by quantitative mapping of mechanical properties using AFAM, AFM phase imaging, and nanoindentation. According to the obtained images, the widths of the interphase modified with maleic anhydride polypropylene (MAPP) were estimated to be around 40-190 nm. There was a gradient of modulus across the interphase region which ranged between 6 to 11 GPa, while the modulus for fiber was around 13 GPa and bulk polymer was 5 GPa. The results from this research have demonstrated a new technique to evaluate the nanoscale mechanical properties within the interphase. Information about interphase obtained from this technique is very useful for optimum design of final FRPC products. The newest research results from this project have been delivered to academic and industry professionals via three journal publications and eight oral/poster presentations in six international professional meetings. Our presentation has won a poster award during the 51th International Convention of Society of Wood Science and Technology in Chile. Two manuscripts have been submitted into refereed journals for possible publication during this reporting period. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
This work has developed an improved understanding of interphase in fiber reinforced polymer composite under nano or sub-macro scale. The present study also ingeniously relates the cell-wall longitudinal hardness and stiffness to the composite processes. The nanoindentation could be used as a routine tool for quality control of raw materials.
Publications
- Lee, S., S. Wang and Y. Teramoto. 2008. Isothermal crystallization behaviour of hybrid biocomposite consisting of regenerated cellulose fiber, clay, and poly (lactic acid). Journal of Applied Polymer Science 108: 870-875.
- Zhou, Z., Y. Zhang and S. Wang. 2008. Nanoindentation testing technique of wood and wood-based composite materials based on AFM. China Forest Products Industry 35(2): 23-26.
- Xing, C., S. Wang, G.M. Pharr and L. Groom. 2008. Effect of thermo-mechanical refining pressure on the properties of wood fiber as measured by nanoindentation and atomic force microscopy. Holzforschung 62(2): 230-236.
- Nair, S.S., S. Wang, D. Hurley. 2008. Evaluation of interphase properties in fiber reinforced polymer composite using contact resonance force microscopy. Proceedings of the 51th International Convention of Society of Wood Science and Technology, November 10-12, Concepcion, Chile. Pp. 1-9.
- Zhou, Z., Y. Zhang and S. Wang. 2008. Nano-mechanical properties of the pre-compressed poplar cell wall based on nanoindentation. Proceeding of IPC working Party on Harvesting and Utilization of Poplar and Willow Wood conference, Engineered wood Products Based on Poplar/Willow Wood, Nanjing, China, October 21-24. Pp55-64 (ISBN 9789080656574).
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Progress 09/01/06 to 08/31/07
Outputs
OUTPUTS: In order to understand the interphase between fiber and matrix in natural fiber reinforced polymer composites (NFRPC), we have to characterize both fiber and matrix very well, especially in the nano scale. With nanoindentation and AFM, we have conducted characterization of a wide range of natural fibers that are potential to be used as natural reinforced materials. The regenerated cellulose fibers and wood fibers have been studied. Through using regenerated cellulose fiber as a model material, we have investigated the relationship between nanoindentation based modulus and nano-tensile based modulus. Ten hardwood species have been tested to investigate effect of species on nano mechanical properties of wood cell walls. Effect of refining process on nano-mechanical properties of wood fibers was also been studied. Micro-thermal analysis has been used to characterize interphase between lyocell fiber and polypropylene. The 20 nm wideness of interphase can easily be visualized. Studies of interphase using nano-scratching are starting. We have developed additional partners from the Oak Ridge National Laboratory to conduct this project using some of their new techniques and facility which were not proposed in our proposal. The newest research results from this project have been delivered to academic and industry professionals via four journal publications and nine oral/poster presentations in five international professional meetings. Two manuscripts have been submitted into refereed journals for possible publication during this reporting period. PARTICIPANTS: Individuals were working for a part of the project: Yan Wu, Ph. D. Student, University of Tennessee and Nanjing Forestry University; Cheng Xing, Post-doctoral Research Associate, University of Tennessee; Partner organizations: ORNL (Oak Ridge National Laboratory) Nanjing Forestry University, China
Impacts
This work has developed an improved understanding of cellulose fiber property under nano or sub-macro scale. The present study also ingeniously relates the cell-wall longitudinal hardness and stiffness to the wood resource and processes. The nanoindentation could be used as a routine tool for quality control of raw materials.
Publications
- S. S. Nair and S. Wang. 2007. Characterizing wood cell wall using microthermal analysis and atomic force microscopy. Abstract IN: Biographies and Abstracts. Forest Products Society 61st International Convention, Knoxville, Tennessee, June 10-13. pp. 14.
- Lee, S., S. Wang, G. Pharr and H. Xu. 2007. Evaluation of interphase property in a cellulose fiber-reinforced polypropylene composite by nanoindentation and finite element analysis. Composites Part A_Applied Science and Manufacturing 38(6): 1517-1524.
- Lee, S., S. Wang, G. Pharr, M. Kant and D. Penumadu. 2007. Mechanical properties and creep behaviour of lyocell fibers by nanoindentation and nano-tensile testing. Holzforschung 61(3): 254-260.
- Wu, Y., D. Zhou, S. Wang, and Yang Zhang. 2007. The application of nanoindentation technique in wood science. The International Forest Research 20(3): 51-55 (in Chinese).
- Wang, S., Y. Wu, C. Xing, G. Pharr, d. Zhou and Y. Zhang. 2007. Comparing nano-mechanical properties of the wood cell wall by nanoindentation. Abstract IN: IUFRO All Division 5 Conference Forest Products and Environment: A Productive Symbiosis. Grand Hotel, Taipei, Taiwan. Oct. 29-Nov. 2, 2007. pp. 154.
- Wang, S., G. Pharr, and S.H. Lee. 2007. Characterization of interphase in natural fiber reinforced polymer composites. Abstract IN: Genes to Products: Agricultural Plant, Microbe, and Biobased Products Research. Bethesda Marriott, Maryland, March 12-14. p. 232-233.
- C. Xing, S. Wang, G. Pharr, L. Groom and S.H. Lee. 2007. Effect of refining on nano-mechanical properties of MDF fibers. Abstract IN: Biographies and Abstracts. Forest Products Society 61th International Convention, Knoxville, Tennessee, June 10-13. pp. 15.
- Wang, S., SH Lee, C. Xing, G.M. Pharr. 2007. Nano mechanical properties of cellulosic fibers by nanoindentation. Abstract IN: 2007 International Conference on Nanotechnology for the Forest Products Industry, June 13-15, Knoxville, TN. pp. 27 (invited oral presentation).
- Wang, S., SH. Lee, C. Xing, G.M. Pharr. 2007. Determination of nano mechanical properties of lignocellulosic fibers by nanoindentation and its limitation. Abstract IN: Workshop on in situ methods in nanomechanics. Lawrence Berkeley National Laboratory, Berkeley, California, Aug. 1-3. pp. 37 (Poster presentation).
- Y. Wu, S. Wang, D. Zhou, Y. Zhang. 2007. Nano-mechanical properties of wood cell wall: species influence. Abstract IN: Forest Products Society 61th International Convention, Knoxville, TN, June 10-13. pp. 15.
- Y. Wu, S. Wang, D. Zhou, Y. Zhang. 2007. Cell wall nano-mechanical properties of crop stalks by nanoindentation. Poster presentation at International Conference on Nanotechnology for the Forest Products Industry, June 13-15, Knoxville, TN, USA. Pp. 62.
- Lee, S.H., S. Wang, Y. Teramoto, T. Rials. 2007. Visualization of interphase between lyocell fiber and polypropylene by AFM. Poster presentation at International Conference on Nanotechnology for the Forest Products Industry, June 13-15, 2007, Knoxville, TN, USA. Pp. 87.
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Progress 09/01/05 to 08/31/06
Outputs
This project is focused on characterizing the mechanical and thermal properties at interphase and interfacial adhesion properties in natural fiber reinforced polymer composites (NFRPC) by various nanoindentation techniques and micro-thermal analysis (μ-TA). During this reporting period, the nanoscale mechanical properties of the interphase in a cellulose fiber-reinforced polypropylene composite were investigated using the continuous nanoindentation technique. The interphase was modified by maleic anhydride PP and γ-APS sizing on fiber surface. The continuous nanoindentation with different indentation depth and spacing was conducted to measure nano-scale hardness and elastic modulus. To evaluate the interphase, a line of indents was produced from the fiber to the matrix. A gradient profile in the hardness and modulus across the interphase region was observed. The distinct properties of the transition zone were revealed by 1-4 indents, depending on
nanoindentation depth and spacing. Before we can understand interphase properties, we should need to understand nano-mechanical properties of both fiber and matrix. We have measured time-dependent nano-mechanical properties of regenerated cellulose fiber and wood cell wall by continuous nanoindentation technique. We also investigated biodegradable cellulose diacetate-grafted-poly(L-lactide)s copolymers by nanoindentation. The newest research results from this project have been delivered to academic and industry professionals via journal publication and professional meetings. Three manuscripts have been submitted into refereed journals for possible publication (two of them have been accepted) and two manuscripts have been submitted for publication in proceedings. We have presented four oral presentations and three poster presentations at six national and international conferences. Following is a list of presentations without publishing an abstract or proceeding paper. We have recruited
a graduate student to work on this project.
Impacts
This project addresses the fundamentally important issue of polymer/biofiber interfacial properties by using relatively new nanoindentation and nano-scratching techniques. The interphase in fiber-reinforced composite materials is very important, and a better understanding of the properties and characteristics of interphase will be helpful to evaluate the overall properties of composite materials. Critical and essential information about interphase that will be obtained will be very useful for optimum design of final natural fiber reinforced polymer composites (NFRPC) and for the whole area of composites from renewable resources. This research would help the introduction of natural fibers into new applications in polymer composites.
Publications
- Lee, S.H, Wang, S., and G. Pharr. 2005. Characterization of interfacial properties between cellulose fiber and thermoplastic by AFM and nanoindentation. Poster presentation at the 230th ACS National Meeting, SCI-MIX session, Washington, DC, Aug 28-Sept 1, 2005.
- Wang, S., S.H. Lee, W.T.Y. Tze, T. Rials, G.M. Pharr. 2006. Nanoindentation as a tool for understanding nano-mechanical properties of cell wall and biocomposites. International Conference on Nanotechnology for the Forest Products Industry, Marriott Marquis, Atlanta, GA, April 26-28. 7pp.
- Lee, S., Y. Teramoto, S. Wang, G. Pharr and T.M. Rials. 2006. Nanoindentation of biodegradable cellulose diacetate-grafted-poly(L-lactide)s copolymers-Effect of molecular composition and thermal ageing on mechanical property. Journal of Polymer Science B (in print).
- Lee, S., S. Wang, and G. Pharr. 2006. Nano-mechanical properties and creep behaviour of lyocell fiber by nanoindentation. Holzforschung (in print).
- Lee, S.H., S. Wang and G. M. Pharr. 2006. Time-dependent nano-mechanical properties of regenerated cellulose fiber and wood cell wall by continuous nanoindentation technique. Abstract IN: The 231st ACS National Meeting, Division of Cellulose and Renewable Materials, Atlanta, GA, March 26-30, 2006.
- Lee, S.H, Wang, S., and G. Pharr. 2006. Effect of coupling agent on interphase between natural fiber and thermoplastic by AFM and nanoindentation. Abstract IN: Biographies and Abstracts. Forest Products Society 60th International Convention, Newport Beach, California, June 25-28. pp. 16.
- Wang, S., S.H. Lee, and G. Pharr. 2006. Characterization of interfacial properties between cellulose fiber and thermoplastic by AFM and nanoindentation. Poster presentation at the 1st International Conference on Energy Conversion and Efficient Utilization of Woody Biomass (CECUWB), May 14-16, 2006, Beijing, China.
- Lee, S.H., S. Wang, and G. Pharr. 2006. Nano-mechanical properties of regenerated cellulose fiber by nanoindentation. Poster presentation at the 15th Annual TANDEC Nonwovens Conference, UT Conference Center, Knoxville, Tennessee, April 18-20, 2006.
- S.H. Lee, S. Wang and G.M. Pharr. 2005. Characterization of interfacial properties between cellulose fiber and thermoplastic by AFM and nanoindentation. Abstract IN: 230th ACS National Meeting, Washington, DC.
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