作者机构：
[肖俊华; 左迎峰; 吴义强; 刘文杰; 吴志平; 孟陶陶] College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha;410004, China;[肖俊华; 左迎峰; 吴义强; 刘文杰; 吴志平; 孟陶陶] 410004, China
通讯机构：
[Wu, Y.] C;College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha, China
期刊：
International Journal of Biological Macromolecules,2017年103:1257-1264 ISSN：0141-8130
通讯作者：
Wu, Yiqiang
作者机构：
[Xiao, Junhua; Zhu, Ying; Wu, Yiqiang; Zuo, Yingfeng; Liu, Wenjie; Zhao, Xing] Cent South Univ Forestry & Technol, Coll Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.;[Wu, Yiqiang; Zuo, Yingfeng; Zhao, Xing] Cent South Univ Forestry & Technol, Hunan Prov Collaborat Innovat Ctr High Efficiency, 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：
Dialdehyde starch;Corn starch;Acid hydrolysis and oxidation;Sodium periodate;One-step method
摘要：
Dialdehyde starch was prepared by one-step synthesis of acid hydrolysis and oxidation, using corn starch as the raw material, sodium periodate (NaIO4) as the oxidant, and hydrochloric acid (HCl) as the acid solution. The prepared dialdehyde starch was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and gel permeation chromatography (GPC). The results confirmed that oxidation occurred between the starch and NaIO4. The acid hydrolysis reaction reduced the molecular weight of starch and effectively improved the aldehyde group contents (92.7%). Scanning electron microscope (SEM) analysis indicated that the average particle size decreased after acid hydrolysis and oxidation reaction. X-ray diffraction (XRD) and thermal gravimetric analyzer (TGA) analysis demonstrated that the crystallinity of the obtained dialdehyde starch showed a downward trend and a decelerated thermal decomposition rate. The starch after acid hydrolysis and oxidation exhibited lower hot paste viscosity and higher reactivity.
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.
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：
[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.
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
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.
