作者机构：
[Wu, Yiqiang; Guo, Xin] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.;[Xie, Xinfeng] Michigan Technol Univ, Sch Forest Resources & Environm Sci, Houghton, MI 49931 USA.
通讯机构：
[Wu, Yiqiang] C;Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.
摘要：
Hygroscopic behavior is an inherent characteristic of nanocellulose which strongly affects its applications. In this study, the water vapor sorption behavior of four nanocellulose samples, such as cellulose nanocrystals and nanofibers with cellulose I and II structures (cellulose nanocrystals (CNC) I, CNC II, cellulose nanofibers (CNF) I, and CNF II) were studied by dynamic vapor sorption. The highly reproducible data including the running time, real-time sample mass, target relative humidity (RH), actual RH, and isotherm temperature were recorded during the sorption process. In analyzing these data, significant differences in the total running time, equilibrium moisture content, sorption hysteresis and sorption kinetics between these four nanocellulose samples were confirmed. It was important to note that CNC I, CNC II, CNF I, and CNF II had equilibrium moisture contents of 21.4, 28.6, 33.2, and 38.9%, respectively, at a RH of 95%. Then, the sorption kinetics behavior was accurately described by using the parallel exponential kinetics (PEK) model. Furthermore, the Kelvin-Voigt model was introduced to interpret the PEK behavior and calculate the modulus of these four nanocellulose samples.
作者机构：
[Xiong Feng; Luo Yong-Feng; Liao Chun-Rong] Cent South Univ Forestry & Technol, Coll Sci, Changsha 410018, Peoples R China.;[Xiong Feng; Luo Yong-Feng; Liao Chun-Rong] Fudan Univ, Lab Adv Mat, State Key Lab Mol Engn Polymers, Shanghai 200438, Peoples R China.;[Li Xian-Jun; Wu Yi-Qiang] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410018, Peoples R China.
通讯机构：
[Luo Yong-Feng] C;[Luo Yong-Feng] F;Cent South Univ Forestry & Technol, Coll Sci, Changsha 410018, Peoples R China.;Fudan Univ, Lab Adv Mat, State Key Lab Mol Engn Polymers, Shanghai 200438, Peoples R China.
关键词：
Conductive polymer;Fiber;Supercapacitor;Solar cell;Fibrous energy device
摘要：
Conductive polymers implemented in fibrous energy devices have drawn considerable attention because of their economic importance, good environmental stability, and electrical conductivity. Conductive polymers demonstrate interesting mechanical, electronic, and optical properties, controllable chemical and electrochemical behavior, and facile processability. This review elaborates on the latest research in conductive polymers in fibrous energy devices, such as fibrous supercapacitors, fibrous solar cells, and fibrous integrated energy devices. The performance requirements of these fibrous energy devices, with specific reference to related materials, fabrication techniques, fiber structure, and electronic transport as well as mechanical functionality, are also reviewed in this paper.
作者机构：
[郭鑫; 吴义强; 李贤军] College of Material Science and Engineering, Central South University of Forestry and Technology, Changsha, 410004, China;[郭鑫] College of Sciences, Central South University of Forestry and Technology, Changsha, 410004, China
通讯机构：
College of Material Science and Engineering, Central South University of Forestry and Technology, Changsha, China
关键词：
wood;water distribution;existing states
摘要：
Wood-water relationship has been studied since the beginning of wood research. With the development of new technology,vast modern analytical method are emerging,and the study of wood-water relationship is changing from macro to micro scale and from cell to molecular level. The main objective of this paper was to review the modern analytical techniques which have been applied to study the wood-water relationship. This paper was divided into four parts. Firstly, the extremely heterogeneity of the wood cell wall structure and chemical composition and the highly complex states of water were discussed,and then the distribution and existing states of water in wood was summarized as an active field of the research about wood-water relationship. Secondly,the application of four kinds of analytical techniques,such as magnetic resonance imaging(MRI),computed tomography(CT),neutron imaging(NI) and vibrational spectroscopic imaging,in the study of water distribution were summarized. Meanwhile,the advantages and limitations of these four techniques were provided. Some of the latest research progress was: Vibrational spectroscopic imaging techniques such as micro-FTIR and confocal Raman could offer visual examination and spectral information of chemical functional groups in situ,and owned high spatial resolution on the micrometer length scale. The spatial resolution of micro-FTIR imaging technique was 6.25 μm by the instrumental parameters,and the spectral changes indicated that the adsorbed water concentration was nonuniform at the cell structure level. Meanwhile,the spatial resolution of confocal Raman imaging technique was higher than 1 μm,and the spectral changes indicated that the amount of water in the cell corner(CC) was less than that in the middle layer of secondary wall(S2) throughout the entire range of relative humidity(RH) levels. Thirdly,the recent advances in the application of four kinds of analytical techniques,such as near infrared(NIR) spectroscopy,nuclear magnetic resonance(NMR),fourier transform infrared spectroscopy(FTIR) and Raman spectroscopy,were discussed in the study of existing states of water in wood. The advantages and limitations of these four techniques were also provided. Some of the latest research progress was: The micro-FTIR spectroscopy and a specially designed sample cell were used to examine the molecular association of adsorbed water with wood during adsorption process. It was confirmed that carboxyl CO,C—O groups as well as OH groups were active sites for water adsorption. Meanwhile,strongly,moderately and weakly hydrogen-bonded water molecules were identified and assigned. What's more,according to the variation trend of these hydrogen-bonded water molecules,three sections were divided for adsorption process. Furthermore,the existing states of water in each section was demonstrated as CO…(HOH) …OH or OH…(OH_2) …OH、WATER…HOH… WATER,and tetrahedral structure. Finally,some future research subjects in the research about wood-water relationship were proposed,such as applying new approaches with greater accuracy and higher resolution,developing the convincing component band analysis.
摘要：
Esterified starch/polylactic acid (ES/PLA) blending composite was prepared by melting extrusion with maleic anhydride esterified starch and PLA as the raw materials. The composite was accelerated aging by using UV aging box, and its properties were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), thermo gravimetric analysis (TGA) and mechanical testing machine. FT-IR and SEM results show that the infrared absorption peak intensities of C-O, C-H, and C=O in aged samples decrease gradually with increasing aging time. The damage degree of surface and internal of aged samples increases gradually. XRD analysis results show that after aging treatment, the crystalline diffraction peak of thermoplastic esterified starch at 2θ = 21° disappears and the diffraction peaks of PLA at 2θ = 16.5° appear, indicating that the hydrolysis rate of esterified starch is greater than that of PLA. The crystallinity of PLA in aged sample shows an increasing trend at first followed by a decreasing one along with the increasing time of aging treatment, suggesting that the hydrolysis of amorphous regions of PLA is more preferential than its crystalline regions. Because of the influence of crystal structure and the change of composition structure, the initial decomposition temperature of aging test specimen gradually increases with the extension of aging time. The maximum decomposition rate temperature and residual mass increases at first, and then decrease after the aging time extending to 1 600 h. As the aging time increases, the damage degree of combination interface between esterification starch and PLA is exacerbated, resulting in the tensile strength and bending strength of aged specimen decreasing gradually.
期刊：
材料导报,2017年31(12):96-100 and 104 ISSN：1005-023X
通讯作者：
Wu, Yiqiang(wuyq0506@126.com)
作者机构：
[肖俊华; 王健; 左迎峰; 吴义强] College of Material Science and Engineering, Central South University of Forestry and Technology, Changsha;410004, China;[詹满军] Guangxi Fenglin Wood Industry Group Co. Ltd., Nanning;530031, China;[陈秀兰] Dare Wood-based Panel Group Co. Ltd., Zhenjiang
通讯机构：
[Wu, Y.] C;College of Material Science and Engineering, Central South University of Forestry and Technology, Changsha, China
作者机构：
[左迎峰; 吴义强; 佘佳荣; 郭鑫; 江萍] College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha;410004, China;[顾继友] Key Laboratory of Bio-Based Material Science and Technology of Ministry of Education, Northeast Forestry University, Harbin;150040, China;[左迎峰; 吴义强; 佘佳荣; 郭鑫; 江萍] 410004, China
通讯机构：
[Wu, Y.] C;College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, China
摘要：
The application of superhydrophobic wood is majorly limited by its durability when subjected to natural conditions. Herein, the stability of two representative superhydrophobic woods (i.e., Poplar (Populus tomentosa) and Chinese fir (Cunninghamia lanceolata)), were prepared via a one-step hydrothermal process using tetrabutyltitanate (Ti(OC4H9)(4), TBOT) and vinyltriethoxysilane (CH2CHSi(OC2H5)(3), VTES) as a co-precursor and sequentially tested under different humidity and temperature conditions. The variables including morphology, water contact angle (WCA), color parameter, chemical components of the surface, and moisture absorption property were characterized using a scanning electron microscope (SEM), WCA measurement, a colorimeter, a Fourier transform infrared (FTIR) spectroscopy, and a moisture absorption test, respectively. It was found that initial static WCAs of superhydrophobic wood were larger than 150 degrees. Micron-sized cracks were formed on the coatings after the alternating humidity and temperature aging cycles. This lowered the water repellency, but the WCA was still greater than 140 degrees. There was nearly no chemical change of wood after the aging test; the color change between the same species of untreated and superhydrophobic wood was very small, only with a difference of 0.42 and 4.05 in overall color change DE/values for Chinese fir and poplar, respectively. The superhydrophobic coatings had a trivial influence on wood moisture absorption property, which only lowered 3% in poplar and 2% in Chinese fir, respectively. (C) 2017 Published by Elsevier B. V. This is an open access article under the CC BY-NC-ND license
摘要：
For lignocellulosic materials, water adsorption is extremely important for its product performance. For gaining a deeper understanding of moisture adsorption mechanisms, the molecular interactions between adsorbed water and a typical lignocellulosic material (i.e., wood) were studied using in-situ microscopic Fourier transform infrared (micro-FTIR) spectroscopy and a specially designed sample cell. The spectral shifts of 1733 cm(-1), 1604cm(-1) and 1236 cm(-1) and different spectra between the moist and dry spectra indicated that carbonyl C=O and C-O groups preferred to combine with water molecules to form hydrogen bonds. From component band analysis of the spectral range of 2900-3700 cm(-1), three peaks at 3178 cm(-1), 3514cm(-1) and 3602 cm(-1) were identified and assigned to strongly, moderately and weakly hydrogen-bonded water molecules, respectively. According to the variation trend of these hydrogen-bonded water molecules, three sections were divided for the adsorption process. Furthermore, the molecular structure of water absorbed by hydrophilic groups of wood in each section was demonstrated. (C) 2015 Elsevier B.V. All rights reserved.
作者：
Jiang, Ping;Jia, Shan Shan;Wang, Shuang;Xiao, Jun Hua;Liu, Wenjie;...
期刊：
JOURNAL OF BIOBASED MATERIALS AND BIOENERGY,2016年10(4):284-289 ISSN：1556-6560
通讯作者：
Wu, Yiqiang
作者机构：
[Wu, Yiqiang; Xiao, Jun Hua; Jia, Shan Shan; Wang, Shuang; Jiang, Ping; Liu, Wenjie] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Wu, Yiqiang] C;Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.
关键词：
Chitosan-Graft-Poly(2-(dimethylamino) ethyl methacrylate);pH- and Temperature Responsive;Chitosan;Fresh-Keeping;Grape
摘要：
The pH- and temperature-responsive chitosan-graft-poly(2-(dimethylamino) ethyl methacrylate) (CS-g-PDMAEMA) were synthesized via atom transfer radical polymerization (ATRP) and evidenced by FTIR spectroscopy. Chitosan macroinitiator (CS-Br) was prepared by phthaloylation of amino groups of chitosan and acylation of hydroxyl groups of chitosan with 2-bromoisobutyryl bromide. The pH and temperature responses of the copolymer micelles were characterized by particle diameter and particle size analyzers. The film prepared from CS-g-PDMAEMA was used as a coating film on the surface of the grape. And the film prepared from 1 wt% CS-g-PDMAEMA solution was able to slow the loss of water in grape. The results revealed that the CS-g-PDMAEMA had potential application as active coating materials in the storage of fresh grape.
作者机构：
College of Material Science and Engineering,Central South University of Forestry and Technology,Changsha 410004,China
会议名称：
第三届中国林业学术大会
会议时间：
201309
会议地点：
福州
会议论文集名称：
第三届中国林业学术大会论文集
摘要：
A novel type of hierarchically biomorphic carbons (HBCs) with macro-/ microporous and ordered mesostructure has been successfully prepared by using wood as a mimetic template to reproduce the wood cellular structures,and resol as a precursor,triblock copolymer surfactant as a soft-template to construct the mesostructure on the cell wall.Meanwhile,a formation mechanism for the HBCs with ordered mesostructure through evaporation-induced coating and self-assembly method was proposed in detail.X-ray diffraction,scanning electron microscope,transmission electron microscopy and N2 adsorption results indicate that the obtained HBCs have wood cellular structures,ordered mesostructure (P6mm) and high surface areas (~463m2/g).The results show that the mass ratios of PF/poplar shaving showed a greater effect on the pore texture and properties of the HBCs.With a rise in the mass ratios of PF/wood,the mesostructure of HBCs is gradually changed from disordered to ordered 2D hexagonal structure,and the surface areas,pore volumes are increasing accordingly.In addition,the HBCs exhibit good adsorption properties toward organic vapors,demonstrating that this kind of HBCs could be used as a promising material for adsorbents,separation systems.
