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Yang R, Dong X, Chen G, Lin F, Huang Z, Manzo M, Mao H. Novel Terahertz Spectroscopy Technology for Crystallinity and Crystal Structure Analysis of Cellulose. Polymers (Basel) 2020; 13:polym13010006. [PMID: 33375052 PMCID: PMC7792770 DOI: 10.3390/polym13010006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 12/14/2020] [Accepted: 12/19/2020] [Indexed: 11/25/2022] Open
Abstract
Crystallinity is an essential indicator for evaluating the quality of fiber materials. Terahertz spectroscopy technology has excellent penetrability, no harmful substances, and commendable detection capability of absorption characteristics. The terahertz spectroscopy technology has great application potential in the field of fiber material research, especially for the characterization of the crystallinity of cellulose. In this work, the absorption peak of wood cellulose, microcrystalline cellulose, wood nano cellulose, and cotton nano cellulose were probed in the terahertz band to calculate the crystallinity, and the result compared with XRD and FT-IR analysis. The vibration model of cellulose molecular motion was obtained by density functional theory. The results showed that the average length of wood cellulose (WC) single fiber was 300 μm. The microcrystalline cellulose (MCC) was bar-like, and the average length was 20 μm. The cotton cellulose nanofiber (C-CNF) was a single fibrous substance with a length of 50 μm, while the wood cellulose nanofiber (W-CNF) was with a length of 250 μm. The crystallinity of cellulose samples in THz was calculated as follows: 73% for WC, 78% for MCC, 85% for W-CNF, and 90% for C-CNF. The crystallinity values were obtained by the three methods which were different to some extent. The absorption peak of the terahertz spectra was most obvious when the samples thickness was 1 mm and mixed mass ratio of the polyethylene and cellulose was 1:1. The degree of crystallinity was proportional to the terahertz absorption coefficients of cellulose, the five-movement models of cellulose molecules corresponded to the five absorption peak positions of cellulose.
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Affiliation(s)
- Rui Yang
- Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China; (R.Y.); (X.D.); (G.C.)
- Dehua Tubaobao New Decoration Material Co., Ltd., Huzhou 313200, China
| | - Xianyin Dong
- Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China; (R.Y.); (X.D.); (G.C.)
| | - Gang Chen
- Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China; (R.Y.); (X.D.); (G.C.)
| | - Feng Lin
- Advanced Analysis and Testing Center, Nanjing Forestry University, Nanjing 210037, China;
| | - Zhenhua Huang
- Department of Mechanical Engineering, University of North Texas, Denton, TX 76207, USA; (Z.H.); (M.M.)
| | - Maurizio Manzo
- Department of Mechanical Engineering, University of North Texas, Denton, TX 76207, USA; (Z.H.); (M.M.)
| | - Haiyan Mao
- Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China; (R.Y.); (X.D.); (G.C.)
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA 94720, USA
- Jiangsu Chenguang Coating Co., Ltd., Changzhou 213164, China
- Correspondence:
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