基于TG-FTIR和Py-GC/MS的生物质三组分快速热解机理研究

利用热重红外联用仪(TG-FTIR)和快速热解-气相色谱/质谱联用仪(Py-GC/MS),对生物质三组分(纤维素、半纤维素和木质素)的热解失重规律、动力学和挥发分组分及其含量进行了对比研究。TG/DTG曲线表明,纤维素热解失重区间最窄,峰值处热解失重率最大;半纤维的最易发生降解,存在两个失重区间;而木质素热解过程最缓慢,热解温度范围最广。三维FTIR表明,纤维素热解主要产物为CO_2、醛类、酮类和酸类;半纤维素热解主要产物与纤维素一致,但是CO_2含量比其他几类组分高很多;木质素热解主要产物为CO_2和芳香烃类。Py-GC/MS分析表明,纤维素热解有机组分主要为呋喃类和脱水糖类,呋喃类产物在600℃时达到最大值43.34%,脱水糖类产物在500℃时达到最大值27.78%;半纤维素热解主要产物为酮类和呋喃类,两者含量随着热解温度增加呈逐渐下降趋势;木质素热解主要产物为酚类,总酚含量在热解温度500℃时达到最大值78%,其中愈创木酚型(G-型)酚的含量最高63.43%。     

Lyocell纤丝及其可生物分解的纳米复合材料研究

可生物分解的纳米复合材料是新一代材料,微米和纳米级纤维素纤丝具有环保性和潜在的低密度及高强度,可用来制造能生物分解的纳米复合材料.为了描述用一种新的机械方法从Lyocell纤维中分离出的纤丝的特性,以及探索这种纤丝能否增强生物分解的聚合物,笔者用偏振光显微镜(PLM)和扫描电子显微镜(SEM)研究了纤丝的几何特性,用宽角X光衍射法(WAXD)分析了其结晶度,纤维的纤丝化程度用水分保持值(WRV)进行了评价;纤丝增强的聚乳酸(PLA)纳米生物复合材料由模压法制备,用拉伸试验来检测其力学强度,采用SEM来观察其断面特性.结果表明:纤丝提高了PLA的弹性模量和拉伸强度,但纤丝和聚合物基质之间的结合强度很弱.     

Immobilization of cross-linked In-doped Mo(O,S)2 on cellulose nanofiber for effective organic-compound degradation under visible light illumination

Relatively small amounts of In-doped Mo(O,S)₂(IMS) catalysts(10%, 20%, and 30%) were deposited on cellulose nanofiber(CNF) by cross-linking them with functional groups of siloxane and epoxy to form CNF-IMS hybrid composites. The as-prepared hybrid composites were characterized and tested their performances toward the photo degradations of cationic(MB and Rh B) and anionic(MO) dyes. As indium was doped into Mo(O,S)₂ lattice to form solid-solution, the charge transfer and pho...     

Esterified cellulose nanocrystals for reinforced epoxy nanocomposites

The surface of cellulose nanocrystals (CNCs) was successfully modified with methacryloyl chloride to create esterified CNCs (M/CNCs). The modification was confirmed by Fourier Transfer Infra-Red Spectroscopy, X-ray Photoelectron Spectroscopy and Zeta potential measurement. With increased surface hydrophobicity, this modified CNC material exhibited improved compatibility with organic network. When used as a filler to be incorporated into a model epoxy resin, TEM results indicated that M/CNCs particles dispersed well in the epoxy network. It was observed that the inclusion of the M/CNCs had an impact upon the heat flow for the curing of the epoxy nanocomposite, leading to an improvement in the storage modulus when tested via dynamic mechanical analysis.     

菌肥不同施用方法对烤烟假植苗的影响

通过对假植苗床期烟苗采用菌肥不同施用方法的试验研究,结果表明:假植成活后叶面喷施,假植时蘸根,混拌营养土后假植三种不同施用方法均有利于培育壮苗,促进烟苗的生长发育。其中以蘸根假植的效果较好。