壳聚糖/活性炭复配水处理剂制备及应用研究

采用微波法制备了交联壳聚糖,与活性碳复配得到复合吸附剂,并研究其对水中卤化物的吸附效果。结果表明,微波法制备复合交联壳聚糖吸附剂简化了制备工艺,且吸附效果较好。     

微波法羧甲基壳聚糖制备及其对Cu~(2+)吸附性能的研究

在微波辐射下,以壳聚糖为原料,研究了碱用量、氯乙酸用量、反应温度和微波加热时间四个因素对羧甲基壳聚糖制备的影响。并将其用于对废水中Cu2+的吸附,考察了不同pH,羧甲基壳聚糖的用量,振荡时间及溶液中Cu2+初始浓度对吸附性能的影响。结果表明最佳合成羧甲基壳聚糖的工艺条件为1.0g壳聚糖,6.0mL30%氢氧化钠溶液,1.4g氯乙酸,反应θ为50℃,微波加热t为20 min。当溶液pH为5.45,羧甲基壳聚糖投加量为0.03 g,振荡t为1.5 h,Cu2+初始质量浓度为300 mg/L时,在此条件下羧甲基壳聚糖对Cu2+溶液的吸附量为177.83mg/g。     

微波技术提取高脱乙酰度高黏度壳聚糖的实验研究

壳聚糖作为一种具有独特性能的天然高分子生物材料，其应用越来越广泛，并且对壳聚糖品质的要求也越来越高。高脱乙酰度和高黏度是壳聚糖的二个重要质量指标，传统制备工艺中，通过提高反应温度和延长反应时间，能得到高脱乙酰度的壳聚糖产品，但由于过长的反应时间使黏度大大降低。本文采用微波技术和传统工艺相结合，通过正交试验确定了从虾壳中提取高脱乙酰度高黏度壳聚糖的较优工艺条件。     

酶载体壳聚糖制备的研究

本文分别采用电热法、连续微波法和问歇微波法制备了几种性能不同的壳聚糖,并对产品的脱乙酰度和分子量进行了比较.结果表明,间歇微波法制备的壳聚糖具有制备时间短、产品脱乙酰度高和分子量大等特点,能更好地满足酶载体的要求.     

微波辐射下甲醛交联壳聚糖的制备及其吸附性能的研究

报道了微波辐射下甲醛交联改性壳聚糖衍生物的制备及其对铜(Ⅱ)的吸附性能,考察了不同溶剂交联度的影响,并测定了交联壳聚糖和壳聚糖对铜(Ⅱ)的吸附量。结果表明,交联后的壳聚糖对铜(Ⅱ)有较好的吸附,并对微波作用进行了探讨。     

微波间歇法快速制备高粘均分子量和高脱乙酰度的壳聚糖

使用微波间歇法可快速制备高脱乙酰度和高粘均分子量的壳聚糖. 单因素实验确定的工艺条件为微波功率800 W,将45%(w)的氢氧化钠溶液与250~380 mm的20 g甲壳素粉以8:1的体积比混合,在100℃下反应10 min,洗涤、微波干燥后在相同条件下再反应1次,共20 min,可制得脱乙酰度为94.5%、粘均分子量1.48×106的白色壳聚糖粉末. 其他制备条件相同,使用电加热法间歇处理甲壳素粉3次,反应共5 h,可以得到脱乙酰度为96.2%、粘均分子量为3.8×105的褐色壳聚糖粉末. 微波间歇法所制壳聚糖的结晶度高,内部有规整的有序结构,用它制备的膜致密,性能优于用电加热法所制壳聚糖制备的膜.     

羧甲基壳聚糖的制备及其应用研究

研究了在水媒介中,利用微波加热使壳聚糖发生羧甲基改性反应。探讨了碱化时间、微波加热时间、投料比等工艺条件对壳聚糖羧甲基化程度及产物收率的影响,并对产物进行了红外光谱分析、取代度测定、粘度分析。确定最佳工艺条件。壳聚糖：氢氧化钠：氯乙酸=1：15：12,碱化时间=2h,微波加热时间=25min,制得羧甲基壳聚糖取代度和收率分别为0．71和83％。     

微波-过氧化氢协同降黏辅助酶法制备壳寡糖

利用微波-过氧化氢协同处理壳聚糖,通过降低壳聚糖的黏度辅助促进其酶解制备壳寡糖。通过单因素实验与正交实验,确定了影响壳聚糖微波-过氧化氢降黏效果的因素主次顺序是微波时间、H2O2的用量、微波功率。优化后的降黏条件是:H2O2添加量为0.1 mL,微波功率为120 W,微波时间为0.5 min,所得壳聚糖黏度比原料黏度降低了96.9%,且并未发生结构的改变。对其酶解的结果表明,经微波-过氧化氢协同降黏再酶解的壳寡糖得率为80.1%,比未经降黏处理的提高了11.8%,产物壳寡糖数均相对分子质量为2 027,平均聚合度为10,明显低于未经降黏处理而直接酶解所得的壳寡糖。     

羧甲基壳聚糖的合成

以壳聚糖原料，采用氟乙酸途径制备方式，得到制备羧甲基壳聚糖最佳工艺路线，并对产物进行了性能测定．其取代度达到90％以上。     

微波条件下制备壳聚糖的研究

利用微波技术并通过加入乙醇降低碱浓度的方法制备了壳聚糖。同时对碱浓度、反应时间、碱用量等因素进行研究 ,确定了最优化条件 :甲壳素与碱液体积比为 1∶2 0 ,碱浓度为 30 %,微波功率为 480W ,反应时间为30min。用优化条件制备的壳聚糖的脱乙酰度 >76 %。     

Physicochemical properties of edible films from chitosan composites obtained by microwave heating

Summary  Chitosan films were prepared by casting, using microwave and dried by air convection. No scientific literature covers the use of microwave heating in the preparation of chitosan films by casting technique. Effects of heating time, molecular weight and plasticizer on structure, thermal behavior, surface, barrier properties and light transmission were investigated. Heating time showed that the microwave heating did not affect the structural composition and thermal decomposition of chitosan films. UV-vis light barrier properties, equilibrium moisture content and water vapor permeability varied significantly with the heating treatment. Surface film analysis revealed no captured differences between different heating treatments.     

微波合成纳米氧化锌及其应用研究进展

介绍了近年来微波技术在制备特殊形态和性能的纳米氧化锌中的方法应用及纳米氧化锌的晶体生长机理,阐述了利用微波技术制备的纳米氧化锌在应用于催化合成有机物和光催化降解有机污染物过程中所表现出的优异性能,并对微波技术在制备纳米氧化锌领域的应用前景进行了展望。     

Colloidal Cu nanoparticles/chitosan composite film obtained by microwave heating for food package applications

In this paper, we describe the preparation and characterization of colloidal Cu nanoparticles/chitosan composite film (composite film) by solution-casting technique with microwave heating. Effects of the incorporation of colloidal Cu nanoparticles on structure, thermal behavior, surface, barrier properties and light transmission of composite film were investigated. The antimicrobial activity of films against Staphylococcus aureus and Salmonella enterica serovar Typhimurium, were also tested. Incorporation of colloidal Cu nanoparticles on chitosan matrix improved the barrier properties of films, decreasing the oxygen permeability as well as water vapor permeability and increasing the protection against UV light. The composite film was effective in alteration of cell wall and reduction of microbial concentration in the liquid culture for both bacteria tested.     

微波交联CTS/GLT共混膜的制备及性能研究

以甲醛为交联剂在微波条件下交联壳聚糖和明胶，成功制备出微波交联CTS／GLT（壳聚糖／明胶）共混膜。研究了膜的力学性能、吸水性和透光率。研究结果表明，最佳制膜条件为微波功率500W，微波辐射时间1．0min，交联剂用量为壳聚糖的0．4％，壳聚糖／明胶质量比为80／20。膜的拉伸强度为56．39MPa，吸水率为1．33％，透光率为92．3％。     

阿司匹林-壳聚糖缓释微球的制备和释药性能研究

采用乳化交联法制备阿司匹林-壳聚糖缓释凝胶微球,通过透析实验检测微球的体外释放特性。应用正交实验设计,考察了壳聚糖浓度,搅拌速度,阿司匹林/壳聚糖质量比,交联时间对微球制备的影响。体外释放实验表明,壳聚糖微球前5个小时的释放符合SRP的释药行为。以5个小时的体外释放总量为指标进行直观分析,交联时间对5小时的体外释放总量影响最大。     

负载型金属催化剂制备新技术研究进展

负载型金属催化剂因为其独特的催化性能在众多领域得到广泛应用。传统的催化剂制备方法有浸渍法,沉淀法,离子交换法和熔融法等。文章综述了溶剂化金属原子浸渍法,超临界技术和微波技术在负载型金属催化剂制备中的应用。     

Novel 3D scaffolds of chitosan-PLLA blends for tissue engineering applications: Preparation and characterization

This work addresses the preparation of 3D porous scaffolds of blends of chitosan and poly(l-lactic acid), CHT and PLLA, using supercritical fluid technology. Supercritical assisted phase-inversion was used to prepare scaffolds for tissue engineering purposes. The physicochemical and biological properties of chitosan make it an excellent material for the preparation of drug delivery systems and for the development of new biomedical applications in many fields from skin to bone or cartilage regeneration. On the other hand, PLLA is a synthetic biodegradable polymer widely used for biomedical applications. Supercritical assisted phase-inversion experiments were carried out in samples with different polymer ratios and different polymer solution concentrations. The effect of CHT:PLLA ratio and polymer concentration and on the morphology and topography of the scaffolds was assessed by SEM and Micro-CT. Infra-red spectroscopic imaging analysis of the scaffolds allowed a better understanding on the distribution of the two polymers within the matrix. This work demonstrates that supercritical fluid technology constitutes a new processing technology, clean and environmentally friendly for the preparation of scaffolds for tissue engineering using these materials.     

降解制备壳寡糖研究进展

壳寡糖因具有多种生物活性,成为国内外研究的热点,其制备技术是壳聚糖产业研究开发的重点领域。壳寡糖的制备方法主要有化学法、酶解法和综合法。本文对壳寡糖的制备方法及其作用机理进行了综述。     

(Zr_(1-x)Sn_x)TiO_4(ZST)微波介质陶瓷制备技术及其应用的研究进展

本文介绍了ZST微波介质陶瓷的性能、微观结构,总结了近年来有关ZST微波介质陶瓷制备技术及其应用的研究进展,主要包括粉末制备、烧结、后处理以及性能预测等方面,指出了ZST介质陶瓷的发展方向。