2-羟丙基三甲基氯化铵壳聚糖的制备及其性能研究

以脱乙酰度为95.37%的壳聚糖(CTS)为原料,异丙醇为溶剂,2,3-环氧丙基三甲基氯化铵为改性剂,于80℃反应12 h合成了水溶性季铵盐2-羟丙基三甲基氯化铵壳聚糖(HACC)。HACC的吸水保水性是CTS的2倍～3倍,加入化妆品中培养2周后菌落总数少于100 CFU.g-1。     

阳离子改性壳聚糖的合成工艺

弱碱性条件下,在壳聚糖（CTS）上引入2-羟丙基三甲基氯化铵（CTA）基团,使其阳离子化。采用正交试验通过测定合成产物的取代度确定其最佳合成条件,再用红外光谱对产物结构进行表征。结果表明：CTS/CTA质量比=1∶5,溶胀时间60 min,碱化温度35℃,反应温度60℃,反应时间9 h为该工艺的优化条件,在此条件下合成...     

CTA季铵化壳聚糖合成条件的优化及其结构表征

以3-氯-2-羟丙基三甲基氯化铵(CTA)为改性剂,在碱性条件下制备了水溶性壳聚糖季铵盐,并以该产物对Cr2O7^2-的絮凝去除率为基准优化了合成条件,用IR和^1H-NMR表征了产物结构。结果表明,优化的合成条件为：反应时间为10．0h,温度为65．0℃,mNaOH／mCTS=1．0,mCTA／mCTS=4．0。在此条件下合成的产物对Cr2O7^2-的最大去除率达94．39％,壳聚糖的季铵化反应主要发生于C2位的氨基上。     

羟丙基三甲基氯化铵壳聚糖的制备及其吸湿、保湿性能

抑菌活性;羟丙基三甲基氯化铵壳聚糖的制备及其吸湿、保湿性能     

干法制备阳离子淀粉（Ⅰ）：反应效率的研究

在碱催化剂BZ-1存在下,以N-（2,3-环氧丙基）三甲基氯化铵（GTA）为阳离子化试剂,干法制备了高取代度季铵型阳离子淀粉。考察了碱催化剂BZ-1、水含量、反应温度和反应时间对取代度和反应效率的影响。当淀粉用量为5.5g,GTA用量为3g时,最佳反应条件为：碱催化剂BZ-10.8g、反应温度60℃、反应时间4h、反应体系含水量24%,取代度可达0.56,反应效率为88%.     

醚化剂GTA的合成及在制备阳离子聚乙烯醇中的应用

以三甲胺(TMA)和环氧氯丙烷(EPIC)为原料,超声条件下合成了醚化剂失水甘油基三甲基氯化铵(GTA),研究了物料配比、反应温度、反应时间对产物收率的影响,确定GTA最优合成工艺条件:n(TMA)∶n(EPIC)=2∶1,反应温度20℃,反应时间4 h,此条件下产物收率72%。用该中间体在碱性条件下对聚乙烯醇进行改性,可制得季铵盐型阳离子聚乙烯醇膜材料,通过正交实验确定季铵盐型阳离子聚乙烯醇最优合成工艺条件:n(GTA)∶n(PVA)=2∶1,反应温度60~70℃,反应时间5 h,p H为10,终产物收率88%。     

季铵化N,O-(2-羧乙基)壳聚糖的制备及其抑菌性能

以缩水甘油基三甲基氯化铵(GTMA)、缩水甘油基三乙基氯化铵(GTEA)、缩水甘油基三丙基氯化铵(GTPA)、缩水甘油基三丁基氯化铵(GTBA)和缩水甘油基二甲基苄基氯化铵(GDMBA)等活性季铵盐为季铵化试剂,对N,O-2-羧乙基壳聚糖(N,O-2-CEC)进行了化学改性,得到了系列季铵化N,O-2-CEC(QCEC...     

O-2'-羟丙基三甲基氯化铵壳聚糖的合成与表征

通过苯甲醛与壳聚糖反应形成Schiff碱 ,对C2 上氨基进行保护 ,经过 2 ,3 环氧丙基三甲基氯化铵与Schiff碱壳聚糖中间体反应后再脱保护 ,合成了O上取代的季铵盐壳聚糖 ,其结构经IR ,1HNMR及13 CNMR分析表征。实验表明O上取代的季铵盐壳聚糖可溶于H2 O及甲醇、乙醇、乙二醇等有机溶剂中。     

阳离子聚丙烯酸酯乳液的制备及其在造纸中的应用

以缩水甘油醚三甲基氯化铵(GTA)和丙烯酸为原料,合成了阳离子丙烯酸酯单体,研究了反应物配比、温度、时间、及催化剂用量对产物酯化率的影响,确定了产物最优合成工艺为:异丙醇作反应溶剂,n(丙烯酸)∶n(GTA)=1.1∶1,反应温度70℃,反应时间6h,此条件下酯化率78%,产物收率86%.产物结构通过红外光谱得以证实.该单体经种子乳液聚合得到阳离子聚丙烯酸酯乳液,与氧化淀粉复配后制备的阳离子表面施胶剂对提高纸张的强度具有明显作用.     

O-季铵化-N-壳聚糖Schiff碱的合成及表征

对壳聚糖氨基和羟基进行化学改性,合成了水溶性双功能化壳聚糖衍生物O-季铵化-N-壳聚糖Schiff碱(O-HTCCS);用红外光谱表征了产物的结构;确定了O-HTCCS的最佳合成条件,并测定了其溶解性能.结果表明,合成O-HTCCS的最佳条件为:壳聚糖Schiff碱/缩水甘油三甲基氯化铵(GTMAc)摩尔比为1∶5;反应时间24 h;反应温度70℃.在最佳条件下合成O-HTCCS的产率为78.5%,季铵化度为89.7%.与此同时,O-HTCCS的水溶性随季铵化度的增大而提高,季铵化度达到70%以上能溶于水;且其在有机溶剂中的溶解性优于壳聚糖.     

新型类肝素物质的研究(I)——磺化羟丙基壳聚糖凝胶的研制

以片状壳聚糖为原料，制成羟丙基壳聚糖凝胶。以氯磺酸－甲酰胺为磺化试剂，在适当条件下进行磺化，成功地获得了磺化羟丙基壳聚糖凝胶，硫含量为９．４２％。红外光谱分析表明，该磺化衍生物具有类肝素结构，是一种的新型类肝素物质，同时也是一种新型聚阴离子吸附剂，可用于选择性净化血液中的低密度脂蛋白。     

New approach to the quaternization of chitosan and its amphiphilic derivatives

Regioselective quaternization of chitosan and its amphiphilic derivatives has been carried out by means of reaction with betaine in the presence of the coupling reagent 2-ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline (EEDQ) in aqueous media at pH 5.5 ± 0.5. This reaction results in preparation of N-/(trimethylammonio)acetyl/chitosan chloride and its amphiphilic derivatives. The degree of quaternization increases with increasing EEDQ/chitosan ratio and is partly accompanied by N-ethoxycarbonylation. That side-product formation can be minimized by increasing betaine/EEDQ ratio.     

水溶性量子点的制备及其与壳聚糖衍生物的自组装

以3-巯基丙酸(HS-CH2CH2COOH)为稳定剂, 制备了水溶性的碲化镉(CdTe)量子点(QDs), 考察了制备条件对QDs荧光性能的影响及CdTe QDs与壳聚糖及叶酸和聚乙二醇改性的壳聚糖的自组装. 研究发现, 壳聚糖及改性壳聚糖与QDs的复合物荧光强度相对纯的CdTe QDs明显增强, 且QDs被包裹在内核, 复合粒子呈明显的核/壳结构. 改性壳聚糖/QDs复合物较小且尺寸分布更为均一.     

壳聚糖及其衍生物水凝胶的研究进展

综述了近年来壳聚糖及其衍生物水凝胶的研究工作进展,介绍了水凝胶的制备方法和应用,尤其是在生物医药方面的广泛应用,并对其未来进行了展望。     

Wastewater treatment containing methylene blue dye as pollutant using adsorption by chitosan lignin membrane: Development of membrane,characterization and kinetics of adsorption

An influential subject of research is the use of lignin for effective removal of hazardous dyes from wastewater effluents utilizing green techniques. Lignin makes up to 10–25% of lignocellulosic biomass. In this study, a solvent evaporation approach was employed to construct a novel chitosan lignin membrane, which was then used to remove the methylene blue (MB) dye from water. The physicochemical, thermal, and morphological attributes were characterized by SEM, XRD, FTIR ATR, and TGA DSC. With higher lignin content in the membrane, its tensile strength was reduced. The dye was removed 95% of the time by the membrane, and the adsorption followed the Langmuir isotherm. The membranes could be recycled up to five times.     

原位沉析法制备壳聚糖棒材的研究

以壳聚糖凝胶膜为模板,将壳聚糖溶液与NaOH凝固液隔离,利用膜渗透原位沉析法制备了高性能的壳聚糖棒材(d=4.5mm),其弯曲强度、弯曲模量和剪切强度分别为92.4MPa,4.1GPa和36.5MPa.扫描电子显微镜(SEM)分析结果表明,原位沉析法制备的壳聚糖棒材具有同心筒状层叠结构,并对其成型机理进行了探讨.     

肝素化壳聚糖季铵盐／壳聚糖复合膜抗凝血性能的研究

以壳聚糖季铵盐，壳聚糖为基本原材料，选用戊二醛为交剂剂及固定剂，制备一种物理机械性能较优的抗凝血材料。探讨了戊二醛及肝素钠两者用量对肝素化程度及血液生的影响。     

Fluoride removal from water by chitosan derivatives and composites: A review

Fluoride is an essential element, indispensable for maintenance of dental health. Nevertheless, fluoride concentrations in drinking water above 1.5 mg L⁻¹ may be detrimental to human health. Many methods have been developed for removing excessive fluoride from drinking water, adsorption seems to be an effective, environmentally friendly and economical one. Since the sorption capacity of fluoride below 2 mg L⁻¹ on most conventional adsorbents is not satisfactory, much effort has been devoted to develop new and cost-effective fluoride adsorbents. This review reports the recent developments in the F⁻ removal in water treatment, using chitosan derivatives and composites in order to provide useful information about the different technologies. When possibly the adsorption capacity of chitosan derivatives and composites under different experimental conditions is reported to help to compare the efficacy of the fluoride removal process. A comparison with the adsorption capacity of other low cost adsorbents is also tabled.     

Environmental effects of chitosan as an immobilization medium for electrochemically active small molecules

Abstract

A number of challenges arise when using ferrocene as a component of electrochemical biosensors, including solubility in aqueous solutions. Therefore, entrapment of the biotin-ferrocene molecules within the chitosan film provides a route for immobilization on an electroactive surface such as an electrode while making the system water compatible. The use of the chitosan-ferrocene bioconjugate thin film on the electrode surface produces a signal that can be monitored in aqueous media. Herein, we discuss a series of modified ferrocene molecules that contain various linkers that provide non-covalent entanglement points to the chitosan medium. The electrochemical analysis and electron microscopy results show marked differences in the ferrocene loaded chitosan polymers when the termini of the ferrocene-linker vary between –SH and –NH₂. The –SH modified systems showed increased reversible and robust electrochemical signals relative to the –NH₂ congeners. Further studies showed that non-covalent impregnation strategy used is robust to degradation and less than 1% of the ferrocene molecules were leached over time. These results indicate that there are specific considerations needed when using chitosan-ferrocene systems as components in sensor arrays in future studies.     

甲壳素的酰基化及其在生物材料上的应用

介绍了甲壳素及其衍生物的酰基化反应、产物的制备方法、酰化产物的性能及其用于生物医用材料上的最新进展。甲壳素及其衍生物的酰基化改性是一种很有价值的化学改性途径，不仅可改善酰化产物在有机溶剂中的溶解性或水溶性，，而且产物作为生物材料具有许多独特的用途。