魔芋葡甘聚糖磷酸盐酯化反应的研究（Ⅱ）

研究了魔芋葡甘聚糖（ＫＧ）与三聚磷酸钠，磷酸二氢钠和磷酸氢二钠分别在干法和固液悬浮法条件下的酯化反应，对酯化反应温度、时间、ｐＨ和磷酸盐用量，以及环境的温度和ｐＨ等对酯化产物（ＫＧＭＰ）水溶胶粘度的影响进行考察，用红外光谱、Ｘ射线衍射和扫描电镜分析了ＫＧＭＰ的结构，阐明了其结构和功能间的关系．     

An Acidic Polysaccharide from Tribulus terrestris

An aqueous acidic polysaccharide, named rhamnogalacturonan (designated as TIP-D2) was isolated from Tribulus terrestris L by means of DEAE-cellulose chromatography and gel filtration. The molecular mass of TTP-D2 was estimated to be 26 KDa by gel filtration.TTP-D2 is composed of galacturonic acid, rhamnose, arabinose, galactose,fucose,mannose,xylose and glucose in a ratio of 71.4:13.5:5.6:4.9:3.1:1.9:1.9:1.0. The main chain structure of TTP-D2 was elucidated as an acidic hetero-polysaccaride with the connection of α-(1-4) galacturonic acid with α-（1-3) rhamnose by GC analysis of partially hydrolyzed products and determination of ^1H,^13C-NMR spectra.     

烷基聚葡糖苷C9.6G1.3/n-C4H9OH/n-C6H14/H2O微乳液体系的介电弛豫谱研究

The pseudotertiary phase diagram of the microemulsion system alkyl polyglucoside/n-butanol/n-hexane/water was plotted at （30.0±0.1） ℃. The dielectric measurements, including permittivity, conductivity, relaxation strength, characteristic relaxation time, etc,, were applied to investigate the microstructure of the system. Unique dielectric relaxations were observed over the frequency range of 5-10^7 Hz, taking place possibly through an interracial polarization mechanism. According to the results obtained from dielectric spectroscopy, the structures of the microemulsion O/W, BC and W/O were determined, and some dielectric and phase parameters were calculated.     

SYNTHESIS AND FLUORESCENCE STUDY OF SELF—AGGREGATION PROCESS IN AQUEOUS SOLUTION OF HYDROPHOBILIZED POLYSACCHARIDE

Cholesterol modified dextran(CHD) having self-aggrgation or self-assembly property was synthesized from cholesterol and 1,6-hexyldiisocyanate.The degree of substitution of cholesteryl moiety in dextran main line is 3-5 cholesterols the 100 glucose units.We have prepared water solution of CHD using probe type sonifier and N-Phenyl-a-naphthylamine(PNA) as a fluorescent probe to study CHD self-aggregate process.For each solution of two samples,we found that the maximum emission of PNA in CHD concentration.This change corresponds to the formation of micelle-like clusters self-aggregated by the cholesterol moiety once the CHD concentration.This change corresponds to the formation of micelle-like clusters self-aggregated by the cholesterol moiety once the CHD concentration exceeds 0.01mg/ml.     

溶液中光诱导产生岩藻黄质自由基正离子的动力学机制

对比研究了岩藻黄质(Fuc)在氯仿和甲醇溶液中光诱导生成自由基正离子(Fuc·+)的动力学过程,考察了2种不同溶剂中Fuc·+产生机制的差异.采用光谱电化学方法结合纳秒时间分辨吸收光谱技术,通过比较直接光激发和三重态敏化2种不同方式诱导生成Fuc·+的动力学过程发现,在氯仿溶液中Fuc·+主要源于Fuc的单重激发态(S2),在甲醇溶液中则主要源于Fuc的三重激发态(T1).     

蔗渣木聚糖磷酸酯的合成与表征

以蔗渣木聚糖为主要原料,正磷酸盐(NaH2PO4与Na2 HPO4)为酯化剂,尿素为催化剂,在湿法工艺下合成了蔗渣木聚糖磷酸酯.考察了酯化温度、酯化时间、蔗渣木聚糖与酯化剂和催化剂配比、pH等因素对取代度的影响,采用正交试验设计对合成条件进行优化,运用统计分析方法探讨了各因素影响的主次顺序和显著性,得到较佳的合成条件为...     

Conversion of xylose and xylan into furfural in biorenewable choline chloride–oxalic acid deep eutectic solvent with the addition of metal chloride

An environmentally benign processing approach for furfural production from xylose and xylan under very mild conditions(353–373 K) was developed with the addition of metal chlorides in ChCl–oxalic acid(a deep eutectic solvent(DES)) synthesized from cheap and renewable starting materials). ChCl–oxalic acid acted as both a Br?nsted acid catalyst and a reaction medium in this catalytic route. In addition, a biphasic system with methyl isobutyl ketone as an extracting reagent(DES/MIBK) to further increase furfural yield was also proposed. This processing approach for producing furfural eliminated the large energy consumption for high pressure saturated steam and the generation of acidic effluent, which was very difficult to handle. The whole catalytic system was more environmentally friendly compared with the commercial process for furfural production.     

一种新型交联羧甲基葡甘聚糖微球对Cr(Ⅵ)的吸附性能研究

通过Fe3+交联羧甲基葡甘聚糖制得了一种新型羧甲基葡甘聚糖凝胶球,研究了羧甲基葡甘聚糖铁凝胶球对Cr(Ⅵ)的吸附性能。分别考察了吸附时间、羧甲基葡甘聚糖浓度、FeCl3浓度、pH值、温度、Cr(Ⅵ)浓度和微球粒径对吸附的影响,同时用红外光谱初步表征了羧甲基葡甘聚糖铁凝胶球-Cr(Ⅵ)复合物的结构。结果表明,293K时,微球对Cr(Ⅵ)的吸附反应在12h时达平衡,当羧甲基葡甘聚糖质量分数为1.0%,FeCl3质量分数为1.0%,Cr(Ⅵ)浓度为400mg/L时,吸附量达到0.4385mmol/g。根据不同温度下微球吸附Cr(Ⅵ)的等温线,计算了吸附过程的热力学参数,同时用Freundlich方程对实验数据进行了拟合,发现该方程适用于所研究的吸附体系。该体系为自发放热过程,体系熵减少,降温有利于吸附。