离子凝胶反应法制备壳聚糖/N,O-羧甲基壳聚糖微球

以一氯乙酸与壳聚糖反应形成N,O-羧甲基壳聚糖两性聚电解质,分光光度法测定其等电点IEP=2．86。以此两性聚电解质与壳聚糖可以在一定条件下形成微球,光学显微镜和电子显微镜测试表明,控制两种聚电解质配比可以制备不同粒径大小的微球,而超声功率对微球粒径的影响较小。红外光谱测试表明微球中N,O-羧甲基壳聚糖羧基以羧酸根形式存在,分光光度与电导法联合测定表明两种聚电解质以离子凝胶作用形成微球,其最佳制备条件为IEP（CM-CHITOSAN）〈pH〈pKa（CS）,在此较宽的pH值范围内微球可稳定存在。     

羧甲基纤维素-壳聚糖水凝胶球的制备及性能

采用物理交联法制备了羧甲基纤维素(CMC)-壳聚糖(CS)共混水凝胶球;研究了共混球的耐酸碱性、溶胀性及对亚甲基蓝的吸附性能.结果表明,水凝胶球在弱酸和弱碱中具有一定的稳定性;随着羧甲基纤维素与壳聚糖质量比的增大,水凝胶的吸水溶胀率增加.在CMC与CS质量比为1∶4时制备的水凝胶呈规则球状.     

新型羧甲基壳聚糖水凝胶的合成与表征

通过1-乙基-(3-二甲基氨基丙基)碳二亚胺盐酸盐(EDC)/N-羟基琥珀酰亚胺(NHS)催化体系使羧甲基壳聚糖(CMCS)交联,制备了新型羧甲基壳聚糖水凝胶.探讨了EDC用量和EDC/NHS质量比对水凝胶特性的影响.CMCS水凝胶具有pH响应特性,在等电位点溶胀率最小.降解实验结果表明,水凝胶浸泡在磷酸盐缓冲溶液中,10 d失重率在15%~45%之间,主要是未交联部分溶解所致.而浸泡在含有0.2 mg/mL溶菌酶的磷酸盐缓冲溶液中,低交联度水凝胶80 h基本降解,高交联度水凝胶不易降解.初步研究了CMCS水凝胶包埋牛血清白蛋白(BSA)的释放行为.     

低碱法制备羧甲基壳聚糖及表征

低碱法制备羧甲基壳聚糖及表征;壳聚糖;羧甲基壳聚糖;取代度;特性粘度;低碱法     

超声波辐射制备羧甲基壳聚糖

应用超声波辐射方法制备水溶性的羧甲基壳聚糖,利用胶体滴定法测定产物中羧基含量,探讨超声波作用下,反应时间、反应温度及反应物投料比对羧甲基化程度的影响。结果表明,在其它反应条件相同时,使用超声波辐射比使用机械搅拌提高羧甲基取代程度,反应时间缩短５ｈ。     

羧甲基壳聚糖离子络合微球的制备及其溶胀性能研究

以羧甲基壳聚糖为主要原料,采用静电脉冲液滴发生器制备了羧甲基壳聚糖离子络合微球。扫描电镜分析结果显示,干球粒径约为100μm。粒径分布均匀。表面呈多孔结构。微球的溶胀行为对溶液pH很敏感,增大pH会促进其溶胀,溶胀速度和最大溶胀度均有提高。pH同时影响载药微球的药物释放性能。微球的溶胀性能受到羧甲基壳聚糖溶液浓度、金属离子种类及其浓度等制备条件的影响。增大羧甲基壳聚糖溶液浓度或金属离子浓度均能提高最大溶胀度,C—Ca微球较C-Al微球更易溶胀。通过改变CaCl2溶液浓度,初步考察了制备条件对药物释放性能时影响。研究对微球进一步应用于药物释放等领域具有重要意义。     

羧甲基壳聚糖微球对活性艳红X-3B的吸附行为研究

用交联的壳聚糖微球(CTS)与氯乙酸在碱性条件下反应,合成了羧甲基壳聚糖树脂(CMCT)。其吸附染料活性艳红X-3B的实验结果表明,CMCT和CTS均对偶氮染料活性艳红X-3B有较好的去除能力。实验条件下,最大平衡吸附量分别为611.5mg/g和365.2mg/g,说明羧甲基的引入提高了壳聚糖的吸附能力。等温吸附可以用Langmuir方程较好的描述,表明为单分子层吸附。动力学过程用二级吸附动力学模拟具有很好的线性相关性,通过二级吸附模型计算出的平衡吸附量与实验值相符。流动床实验表明,CMCT和CTS对浓度为100mg/L的X-3B溶液吸附的穿透点分别为6000ml/g和3375ml/g,用0.1mol/L的氢氧化钠溶液洗脱,洗脱峰集中,洗脱率都在90%以上。洗脱再生后的CMCT和CTS树脂均可重复使用。     

磁性羧甲基壳聚糖复合微球的制备及其对锰离子去除研究

现有水体除锰工艺中存在反应条件较苛刻、锰离子的回收较复杂等问题,而羧甲基壳聚糖经span-80表面活化后包裹Fe_3O_4@SiO_2颗粒,与戊二醛发生交联后制得磁性羧甲基壳聚糖复合微球(MCMCMs),可在温和的条件下吸附水中重金属Mn(Ⅱ),且易于回收。该复合微球粒径约508.26μm,比饱和磁化强度为13.42emu·g~(-1),具有良好的磁稳定性,在磁场作用下可快速分离。在室温下,pH=7、MCMCMs投加量为2g·L~(-1)时,其对Mn(Ⅱ)吸附效果最好,吸附在48h达到平衡,吸附率达到90%以上,且吸附过程高度符合Langmuir吸附平衡模型及二级动力学模型,在25℃时对Mn(Ⅱ)饱和吸附容量约为75.74mg·g~(-1)。MCMCMs回收重复利用性能较好,经过多次氨水洗脱,吸附性能仍可达到初始状态的75%以上,且回收性能与投加量呈现正相关关系。     

羧甲基壳聚糖-Cu(Ⅱ)配合物的制备及其表征

制备了不同摩尔比的羧甲基壳聚糖-铜配合物,运用红外光谱、紫外吸收光谱、循环伏安法、差热-热重分析等手段对配合物进行了结构性能表征。结果表明,羧甲基壳聚糖中的羧基和氨基参与了与Cu2+的配位,生成的羧甲基壳聚糖-铜配合物具有电化学活性,其热稳定性较羧甲基壳聚糖降低。     

Preparation and characterization of microwave-treated carboxymethyl chitin and carboxymethyl chitosan films for potential use in wound care application

CM-chitin and CM-chitosan films were successfully crosslinked by microwave treatment. Crosslinking of the microwave-treated CM-chitin films involved mainly the carboxylate and the secondary alcohol groups, while crosslinking of microwave-treated CM-chitosan films involved the carboxylate and the amino groups. In addition, the crystallinity of CM-chitin increased with increasing microwave treatment time, whereas an increase in the crystallinity of the microwave-treated CM-chitosan films was not observed. At a similar percentage of weight loss, the crosslinking of either CM-chitin or CM-chitosan films by microwave treatment required much less stringent condition when compared with the crosslinking by autoclave treatment. Based on both direct and indirect cytotoxicity assays, the cytotoxicity of the microwave-treated CM-chitin films was negative, while that of the microwave-treated CM-chitosan films was positive. Human fibroblasts adhered on the surface of microwave-treated CM-chitosan films much better than on the surface of microwave-treated CM-chitin films.     

羧甲基壳聚糖修饰的开管毛细管电色谱柱的制备与表征

以γ-(2,3-环氧丙氧基)丙基三甲氧基硅烷为偶联剂,将羧甲基壳聚糖键合至毛细管内壁上。对毛细管预处理、硅烷化以及羧甲基壳聚糖键合反应参数进行了优化,考察了开管柱内表面结构形貌、电渗流、重现性和电色谱分离性能。扫描电镜图显示羧甲基壳聚糖均匀地键合在毛细管内表面。调节流动相的pH值可产生正向和反向电渗流,电渗流的相对标准偏差(RSD): 日内小于0.8%(n=6)、日间小于3.5%(n=3)、同一批次间小于4.3%(n=3)、不同批次柱间小于6.1%(n=3),重现性较好。4种核苷酸(腺嘌呤核苷酸、鸟嘌呤核苷酸、胞嘧啶核苷酸、尿嘧啶核苷酸)在修饰后的毛细管电色谱柱上得到了较好的分离,柱效达到36000～182000 塔板/m。结果表明,所建立的开管柱制备方法简单有效、稳定性好。     

羧甲基壳聚糖对染料废水的脱色研究

纺织工业是我国重要的经济部门,也是我国工业废水的排放大户,其中印染废水排放量又占纺织工业废水排放量的80%,已成为我国各大水域的重要污染源。印染废水的两大污染指标是色度和COD,污染的特点和处理的难点是色度高,脱色困难[1-2]。作为一种天然生物高分子,壳聚糖(chitosan,简称CTS)以其独有的絮凝、成膜、吸附、螯合等性能在印染废水脱色研究领域得到广泛应用[3-8]。作为絮凝剂处理废水时,壳聚糖由于水溶性差而需先溶于稀酸,应用受到一定限制,故人们纷纷将其改性制成水溶性的羧甲基壳聚糖(carboxy-methyt chitosan,简称NOCC)。张秋华[…     

O-羧甲基黄原酸壳聚糖合成及应用研究

以壳聚糖(CS)为原料,先制备出O-羧甲基壳聚糖(OCMC),再和二硫化碳在碱性条件下合成O-羧甲基黄原酸壳聚糖(CXCS)。通过产物的含硫量对碱浓度、投料比和反应时间等因素进行了优化,采用固体13CNMR和SEM表征其结构。结果表明,合成CXCS的最佳条件为碱浓度10%,投料比1∶1,室温反应3h,产品的含硫量达10.22%。最后研究了CXCS对水溶液镉离子的吸附性能,结果表明CXCS具有优异的吸附性能,其最大吸附量可达288.5 mg/g,是壳聚糖吸附量的2.65倍。红外分析结果表明吸附主要依靠结构中的羧基和黄原酸基团。     

羧甲基壳聚糖与钙离子络合作用的研究

羧甲基壳聚糖(carboxymethyl chitosan,CMCS)是壳聚糖Chitosan经化学改性得到的水溶性衍生物,由于羧基的引入,络合金属离子的能力及反应速度大大提高[1-6],在医药、化工、环保等领域有着广泛的应用前景。本文研究了羧甲基壳聚糖与Ca2 络合的条件,着重探讨了Pb2 在不同条件下对络合反应的影响,以期扩大羧甲基壳聚糖的应用范围。1材料与方法1.1仪器与试剂羧甲基壳聚糖(自制),其它试剂均为国产优级纯。TAS-986G原子吸收分光光度计;SX5-12箱式电阻炉;GL-20B高速冷冻离心机;Ori-on818型pH测试计。1.2实验方法1.2.1羧甲基壳聚糖与Ca2 络合…     

羧甲基壳聚糖制备中的溶剂影响及精制方法研究

研究了有机溶剂中两步法制取羧甲基壳聚糖的反应过程.采用有机溶剂溶胀、氢氧化钠碱化、氯乙酸改性、乙醇溶析等步骤制备了高取代度羧甲基壳聚糖.考察了碱用量、氯乙酸用量和有机溶剂类型三个因素对羧甲基壳聚糖取代度的影响.通过比较二甲基亚砜、异丙醇、丙酮和乙醇四种有机溶剂中壳聚糖羧甲基化取代度变化规律,分析了羧甲基化的机理.实验结...     

Synthesis and characterization of novel carboxymethyl chitosan grafted polylactide hydrogels for controlled drug delivery

Novel carboxymethyl chitosan‐polylactide (CMCS‐g‐PLA) hydrogels were prepared by using 1‐(3‐dimethylaminopropyl)‐3‐ethylcarbodiimide hydrochloride/N‐hydroxysuccinimide (EDC/NHS) as crosslinking agent and catalyst at room temperature. Solid‐state ¹³C‐NMR, SEM, and FT‐IR measurements showed that PLA blocks are successfully grafted onto the CMCS main chains. DSC measurements confirmed the effective crosslinking of carboxymethyl chitosan. With increasing the amount of EDC/NHS, the crosslink destiny of CMCS‐g‐PLA copolymers is improved. The swelling ratio of CMCS‐g‐PLA hydrogels is pH dependent, showing a minimum in the pH range of 3 to 5. Rheological studies confirmed the formation of hydrogels. The higher the crosslinking density, the higher the storage modulus of hydrogels. CMCS‐g‐PLA hydrogels only slightly degrade in PBS for 10 days. In the presence of lysozyme, however, hydrogels with low crosslink density are totally degraded in 10 days. Drug release studies show that after 96 h, 95% of thymopentin is released under in vitro conditions. Copyright © 2015 John Wiley & Sons, Ltd.     

壳聚糖共混微球的制备及吸附性能测试

壳聚糖（CS）分子中含有游离态的氨基和羟基,是一种高效的离子吸附剂,而且氨基可质子化形成阳离子,使得壳聚糖对阴离子及两性化合物都具有较强的吸附能力.壳聚糖引入羧甲基后水溶性和反应活性大大增强.实验中以乳化-化学交联法制备壳聚糖/羧甲基壳聚糖（CMC）四种共混微球,通过对比,发现当CS与CMC的质量比为4∶1、2∶3时,成球硬度好,形状明显,大小均匀.随着CMC含量的增加,所成微球对牛血清白蛋白（BSA）的吸附能力逐渐增强.因此,当CS与CMC质量比为2∶3时共混微球自身的物理形态与吸附性能均达到良好状态,是共混高效离子吸附剂的最佳比例选择.     

Preparation,swelling, and stimuli‐responsive characteristics of superabsorbent nanocomposites based on carboxymethyl cellulose and rectorite

Utilization of naturally available raw materials for the fabrication of eco‐friendly functional materials has long been desired. In this work, a series of superabsorbent nanocomposites were prepared by radical solution copolymerization of sodium carboxymethyl cellulose (CMC), partially neutralized acrylic acid (NaA), and rectorite (REC) in the presence of initiator ammonium persulfate (APS) and crosslinker N,N'‐methylene‐bis‐acrylamide (MBA). The optimal reaction variables including the mass ratio of acrylic acid (AA) to CMC, MBA concentration, and REC content were explored. FTIR spectra confirmed that NaA had been grafted onto CMC and REC participated in polymerization. REC was exfoliated and uniformly dispersed in the CMC‐g‐PNaA matrix without agglomeration as shown by XRD, TEM, and SEM analysis. The thermal stability, swelling capabilities, and rate of the nanocomposites were improved after introducing REC, and the gel strength greatly depended on the concentration of crosslinker MBA. The nanocomposite showed excellent responsive properties and reversible On–Off switching characteristics in various saline, pH, and hydrophilic organic solvent/water solutions, which provided great possibility to extend the application domain of the superabsorbent nanocomposites such as drug delivery system. Copyright © 2010 John Wiley & Sons, Ltd.