壳聚糖的脱乙酰度、分子量和浓度对微囊制备和特性的影响（英文）

用不同规格的壳聚糖与海藻酸钠和羧甲基维素钠制备了各种微囊．研究了壳聚糖的脱乙酰度、分子量及溶液浓度对微囊形成和特性的影响．确定了微囊制备的最佳参数,并发现壳聚糖的分子量在一定范围内对微囊通透性无影响而脱乙酰度显著地影响微囊通透性．降低壳聚糖的脱乙酰度可明显增加微囊的通透性,而不影响微囊机械强度．这种微囊制备方法简便、通透性可调,在多种生物活性物质的固定化及药物缓释方面具有重要应用前景     

壳聚糖分离乙醇／水溶液的渗透汽化性能

以脱乙酰化度为77．5％的壳聚糖为原料，采用高温浓碱处理的方法得到脱乙酰化度为98．2％的壳聚糖，分别用这两种壳聚糖制膜，用于乙醇／水混合物的分离结果表明，在同样条件下，脱乙酰化度高的壳聚糖膜的分离性能优于脱乙酰化度低的壳聚糖膜。     

壳聚糖的改性及其自由基清除性能

介绍了不同相对分子质量、不同脱乙酰化度和O-改性壳聚糖的制备方法,综述了壳聚糖清除自由基性能的研究进展.总结了相对分子质量、脱乙酰度和O-修饰等因素对壳聚糖及其衍生物清除自由基的影响.     

甲壳糖的制备和絮凝作用

从除钙和脱乙酰基两个方面，通过比较不同制备条件所制得的甲壳糖对造纸废水ＣＯＤ去除率的影响，探索了适用于实际应用需要的制备工艺条件和甲壳糖作为造纸废水处理的絮凝剂的可能性。     

壳聚糖脱乙酰度的计算

提出应由壳聚糖中氨基质量分数或自由氨基质量分数来计算壳聚糖脱乙酰度。y表示壳聚糖脱乙酰度,x表示氨基质量分数或自由氨基质量分数,理论计算公式分别为:y=203.195x/(16.02262+0.42037x)、y=20.2021x/(16.02262+0.041794x),用计算机拟合,得到以上两式的拟合方程式:y=0.01553+12.64534x-0.31447x²+0.00546x³、y=0.01553+1.25722x-0.00311x²+5.36265×10^-6x³,两方程相关系数R均为1,标准偏差均为0.00663。由拟合方程计算出壳聚糖脱乙酰度,能准确地反映出壳聚糖的实际脱乙酰化程度。     

Influence of chitosan characteristics on the properties of biopolymeric chitosan–montmorillonite

Chitosan–montmorillonite is a modified montmorillonite in which the sodium ions in montmorillonite layers are replaced by biopolymeric chitosan. The effects of characteristics of chitosan (i.e. molecular weight and degree of deacetylation) and the chitosan/montmorillonite mass ratio on the properties of chitosan–montmorillonite were investigated. Thermogravimetric analysis, zeta potential and X-ray diffraction results confirmed intercalation of chitosan into montmorillonite layers. An interaction between chitosan and montmorillonite was revealed by FTIR and the zeta potential. The amount of chitosan intercalated into the montmorillonite layers depended on the characteristics of chitosan, with the largest amounts of intercalated chitosan achieved by addition of chitosan with a molecular weight of 71,000 g/mol or a degree of deacetylation of 80% at a fixed chitosan/montmorillonite mass ratio of 2:1. The resulting chitosan–montmorilllonite had good adsorbent properties, especially for adsorption of cationic dyes, and also inhibited E. coli by almost 100%. The chitosan–montmorillonite may be useful as a functional material for dye adsorption and antibacterial applications.     

Application of Chitosan Flocculant to Conditioning Sludge

The dewaterability of activated sludge conditioned by chitosan flocculant was studied. The effects of chitosan characteristics such as molecular weight, degree of deacetylation, and dose on the dewaterability were investigated. The sludge dewaterability is evaluated in terms of specific resistance to filtration, residual turbidity of supernatant, moisture content of cake, and settling rate. Sludge dehydrating behaviors conditioned with CTS, PAM and PAC flocculants were compared. The conditioning was also carried out with dual flocculants in two stages. It is found that the sludge conditioned with CTS has better dewaterability than that with PAC. The optimum conditions with chitosan are: dose 0.8 - 1.2 g per 100 g dry cake, molecular weight 300,000, and degree of deacetylation 70%. The conditioning in two stages with dual flocculants is found to be more effective than that with single flocculant.     

Inhibitory effects of chitosan on superoxide anion radicals and lipid free radicals

With the electron spin resonance (ESR) technique, the inhibitory effects of chitosan on superoxide anion radicals and linoleic acid lipid radicals were found. The inhibitory ratio E for these two kinds of radicals is in proportion to the concentration of chitosan. It was also observed that E for linoleic acid lipid radicals increased with the increase of the degree of deacetylation and decreased with the increase of the molecular weight of chitosan.     

不同脱乙酰度壳聚糖对活性FM黑的吸附性能研究

以壳聚糖为吸附剂,研究了其对活性FM黑染料的吸附性能.探讨了温度、时间、介质pH值、壳聚糖脱乙酰度以及用量对壳聚糖吸附活性FM黑的影响.结果表明,随着壳聚糖脱乙酰度的增大,壳聚糖的吸附能力随之增强;壳聚糖用量增加,吸附能力先增强后减弱;介质的pH在4～7范围内,对活性FM黑染料废水的吸附性能较好,在中性条件下达到最强;温度对吸附性能的影响较小.由此得出在壳聚糖脱乙酰度为97%、用量为0.006 0g、温度为25℃、反应时间为50min、活性FM黑质量浓度为30mg/L、体积为100mL、介质的pH为7的条件下,吸附量达到273.23mg/g.且其吸附行为满足Langmuir等温式.     

木瓜蛋白酶对壳聚糖的降解特性

研究木瓜蛋白酶催化壳聚糖降解过程中，温度、pH值、酶量、底物质量浓度以及脱乙酰度等条件对降解速率的影响，并通过计算机随机模拟试验，求出壳聚糖的脱乙酰度与GlcNAc-G1cN糖苷键相对含量的关系．结果表明，木瓜蛋白酶只选择性地降解GlcNAc-G1cN糖苷键，反应最适pH值和温度分别为4．5和45℃．     

棉织物的抗菌整理

利用壳聚糖对棉织物进行整理来赋予织物抗菌活性.研究不同浓度、分子量和脱乙酰度的壳聚糖对大肠杆菌和枯草杆菌抗菌性能的影响.采用改良的Quinn方法来测定棉织物的抗菌率,为了使壳聚糖牢固地固着在棉织物上,选用戊二醛作交联剂,整理后的棉织物具有优异的抗菌性.     

壳聚糖荧光标记反应研究

 以壳聚糖-海藻酸钙微球在体检测为研究背景,建立壳聚糖的荧光标记方法.以荧光素异硫氰酸酯(FITC)作为标记化合物,采用紫外-分光光度计在447nm下检测标记在壳聚糖上的FITC,通过m(FITC,μg)/m(壳聚糖,g)表征壳聚糖的荧光标记效率.考察壳聚糖溶液pH值、浓度、反应时间以及壳聚糖分子量、脱乙酰度对壳聚糖荧光标记反应的影响.结果表明:选取相对分子质量20万、脱乙酰度95%的壳聚糖配制成0.01g/mL的溶液,在pH₁₀的条件下与荧光素反应5h将制得标记效率为117.4μg/g的荧光壳聚糖.建立了一种稳定有效的壳聚糖荧光标记方法,为荧光标记壳聚糖-海藻酸钙微球提供了技术支持.     

Chitosan-pectin synergistic interaction and gelation

Mixed gels of chitosan-pectin were prepared by varying the ratio of constituents in the presence of NaCl. Mixed gel at 3% of total polysaccharide concentration with addtion of 12% NaCl showed a synergistic maximum when the ratio of chitosan to pectin was 60: 40. The effect of the polysaccharide concentration, the preparation temperature (T _p), the time of incubation, balk salt concentration, the molecular weight and the degree of deacetylation of chitosan on gelation have been studied. Interaction mechanism between molecules of both polysaccharides was investigated by FT-IR spectrometry. Foundation item: Supported by the National Natural Science Foundation of China (No. 29574173) Biography: He Dong-bao (1945-), male, Associate professor, research direction: natural polysaccharides.     

壳聚糖处理羊毛织物用 M型活性染料染色工艺探讨

文章探讨了pH值、温度对羊毛织物用M型活性染料染色的影响及壳聚糖脱乙酰度、浓度及分子量等对经壳聚糖处理后的羊毛织物染色性能的影响.结果表明,经壳聚糖处理后的羊毛织物用M型活性染料染色,能获得较高的固色率和K/S值.提高处理液中壳聚糖的脱乙酰度或浓度都能提高活性染料对羊毛织物的固色率和K/S值,而且对染色样的湿处理牢度和摩擦牢度影响不大.壳聚糖的分子量对织物的染色性能无明显影响.     

用壳聚糖对织物进行改性的探讨

用不同浓度，不同脱乙酰度的壳聚糖溶液对不同织行进行浸轧处理，并测定了织物的各种性能，实验结果表明，各种织物经过壳聚糖溶液处理后，其上染率，折皱回复角，硬挺度和拒水性都有所提高，纤维素纤维织物的强度有所下降，蛋白质维生素织物的强度则有所上升，壳聚糖的脱乙酰度对织物的性能有一定影响。     

不溶性壳聚糖的再生对苹果汁色值及透光度影响的研究

对不溶性壳聚糖的再生和装柱吸附法进行了研究,探讨不溶性壳聚糖装柱吸附脱色及澄清效果的动态连续操作实验,测定了不溶性壳聚糖再生后对苹果汁的色值和透光度的影响,考察了不溶性壳聚糖吸附性能再生后的衰减情况.结果表明:室温(约20℃)下上吸附柱连续处理苹果汁,10 g不溶性壳聚糖可以连续处理达到国际贸易标准要求的苹果汁2.9 L.与新的不溶性壳聚糖相比,经过再生后的不溶性壳聚糖处理量有所下降,再生10次不溶性壳聚糖的脱乙酰度增加,灰分含量和含氮量均有降低.     

Solid-phase preparation and characterization of Chitosan

0　IntroductionChitosanhasbeenwidelyusedinpharmaceu tical,agriculturalandindustrialfieldbe causeofitsintriguing properties[1 ] .Chemicalmethodstopreparechitosanfromchitinhavebeenbroadlystudiedincludingsolutionmethod ,meltedalkalinemethod,microwavesemi drymethod ,improvedLinelbergmethod ,dissolution precipita tionmethodandsoon ,inwhichalkalinewasallusedasthecatalyst[2 ] .Biologicalmethodwasapromisingwayinthatitproducedlittleenviron mentalpollutionanditsreactionconditionsweremild .However,thism…     

甲壳素的脱乙酰化反应

研究了甲壳素的脱乙酰化反应时,碱溶液浓度、反应时间和反应温度等各种因素对反应产物的脱乙酰度、粘度和红外吸收光谱的影响。结果表明,随溶液中氢氧化钠浓度、反应温度和反应时间增加,甲壳素的脱乙酰化作用增加。甲壳素经一次反应的脱乙酰化度不超过90％。在较低温度和较短时间得到的壳聚糖在稀酸溶液中的粘度较高。     

壳聚糖阻垢效果研究

研究了不同脱乙酰度的壳聚糖对ＣａＣＯ３水样的阻垢效果,以及壳聚糖的浓度,水样Ｃａ＾２＋浓度,溶液温度,ＰＨ恒温时间等对阻垢率的影响,并探讨了壳聚糖与丙烯酸共聚的阻垢效果。     

甲壳糖对Au^3＋氧化还原吸附性能研究

研究了不同脱乙酰度甲壳糖对Ａｕ＾３＋的吸附性能，广角Ｘ－射线衍射实验有甲壳糖能把Ａｕ＾３＋还原成Ａｕ，静态吸附实验结果表明，甲壳糖对Ａｕ＾３＋的吸附量随脱惭酰度的增大而升高脱乙酰时间为４ｈ的甲壳糖对Ａｕ＾３＋的吸附量随溶液ＰＨ值的同而增加；在ＰＨ值等于５．０时吸附量达１１７３ｍｇ／ｇ；另外，随溶液离子强度或高甲壳糖对Ａｕ＾３＋的吸附量减少，吸附动力学实验结果表明，甲壳糖对Ａｕ＾３＋吸附量在１２０ｍ