壳聚糖渗透汽化膜分离醇／水的性能：Ⅱ.壳聚糖复合膜

用聚丙烯腈超滤膜为基膜制成的ＣＳ复合膜，对乙醇／水溶液的分离具有较稳定的透过性，复合膜先后运行于低浓度的乙醇溶液的９５ｗｔ％乙醇溶液，膜的稳定性能优于均质膜。实验还表明用多种交联剂代替硫酸处理超薄复合膜，可有效地提高膜的渗透选择性。     

Blend membranes of chitosan and poly(vinyl alcohol) in pervaporation dehydration of isopropanol and tetrahydrofuran

Blend membranes of a natural polymer, chitosan, with a synthetic polymer, poly(vinyl alcohol) (PVA), were prepared by solution casting and crosslinked with a urea formaldehyde/sulfuric acid (UFS) mixture. Chitosan was used as the base component in the blend system, whereas PVA concentration was varied from 20 to 60 wt %. Blend compatibility was studied by differential scanning calorimetry, and Fourier transform infrared spectroscopy was used to study membrane crosslinking. Membranes were tested for pervaporation dehydration of isopropanol and tetrahydrofuran (THF) at 30°C in close proximity to their azeotropic compositions. Membrane performance was assessed by calculating flux and selectivity. Swelling experiments performed in water + organic mixtures at 30°C were used to explain the pervaporation results. The blend membrane containing 20 wt % PVA when tested for 5 and 10 wt % water–containing THF and isopropanol feeds exhibited selectivity of 4203 and 17,991, respectively. Flux increased with increasing concentration of water in the feed. Selectivity was highest for the 20 wt % PVA‐containing blend membrane. The results of this study are unique in the sense that the crosslinking agent used—the UFS mixture—was novel. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1918–1926, 2007     

新型复合果蔬汁饮料的制作

研究了一种新型复合果蔬汁饮料的制作工艺。以芹菜、番茄和大白菜作为原材料,采用面包酵母驱除蔬菜所带有的异味,以壳聚糖作为新型澄清剂进行复合果蔬汁饮料的澄清,再采用新型抑菌剂羧甲基壳聚糖进行复合果蔬汁饮料的防腐,通过单因素试验和正交试验最终确定复合果蔬汁饮料的最佳配方。结果表明,复合果蔬汁饮料的最佳配方为:番茄汁60%、芹菜汁20%、大白菜汁20%、浓缩苹果汁0.3%、白砂糖2.5%、柠檬酸0.03%。面包酵母驱除蔬菜异味的用量为0.5%、壳聚糖作为澄清剂的用量为0.4 g/L、羧甲基壳聚糖作为防腐剂的用量为0.15%。     

复凝聚法制备农药微胶囊剂的研究

以壳聚糖和木质素磺酸钠为囊材,以三氟氯氰菊酯为囊芯,采用复凝聚法制备了微胶囊。考察了壳芯质量比、温度、搅拌速度、对包药率的影响,确定最佳工艺条件,并对其性能进行了研究。     

交联壳聚糖微球树脂对Cu（Ⅱ）的吸附动力学研究

通过交联壳聚糖微球树脂对Cu（Ⅱ）的静态吸附实验,研究树脂对cu（Ⅱ）的吸附特性．结果表明,pH5—6时,树脂对Cu（Ⅱ）的吸附量较高;Cu（Ⅱ）在交联壳聚糖树脂上的吸附动力学过程符合Lagergren一级动力学吸附方程;吸附速率常数随吸附温度的增加而增大;表观吸附活化能为20．702kJ／mol．     

Equilibrium and kinetics of adsorption of Ca（ II ） ions onto KCTS and HKCTS

The adsorption of Ca(Ⅱ) ions from aqueous solution by chitosan α-ketoglutaric acid(KCTS) and hydroxamated chitosan α-ketoglutaric acid(HKCTS) was studied in a batch adsorption system.The Langmuir and Freundlich adsorption models were applied to describing the equilibrium isotherms,and isotherm constants were determined.The kinetics of the adsorption with respect to the initial Ca(Ⅱ) ions concentration,temperature and pH was investigated.The pseudo-first-order and second-order kinetic models were used to des...     

Evaluation of PLGA/chitosan/HA conduits for nerve tissue reconstruction

A micro-envioment for nerve cells and tissue growth were designed and constructed via surface modification of poly(L-lactide-co-glycolide)(PLGA) with chitosan and hydroxyapatite(HA). The poly(L-lactide-co-glycolide)/chitosan/hydroxyapatite (PLGA/chitosan/HA) conduits were manufactured by a combined solvent casting and particulate leaching technique. The conduits were highly porous with an interconnected pore structure and 76.5% porosity. Micropores with 50–100 micrometer diameter were formed in the conduits. In vivo application of PLGA/chitosan/HA conduits for reconstruction of 10 mm sciatic nerve defect was assessed by the walking track analysis, the quantifying of the wet weight of tibialis anterior muscle and the histological assessment. The conduits in host rats in vivo can not only be an effective in promoting regenerating of nerves but can also lead to favorable nerve functional recovery. Funded by the National Natural Science Foundation of China(No.50774096)     

壳聚糖/羧甲基壳聚糖止血膜的制备与表征

针对壳聚糖止血膜柔韧性差的问题,以丙三醇和酚磺乙胺作为改性剂,采用溶液浇膜的方法制备了不同组成配比的壳聚糖(CS)/羧甲基壳聚糖(CMCS)止血膜,并评价了CS/CMCS止血膜拉伸性能和止血效果.丙三醇的引入可使CS/CMCS止血膜的断裂伸长率提高4~7倍,尽管其拉伸强度也降低了70%.丙三醇改性的CS/CMCS=8/2载药止血膜具有较好的拉伸强度(10.4±0.9 MPa)和断裂伸长率(50.4±4.5%);与未加入酚磺乙胺的CS/CMCS止血膜相比,酚磺乙胺的离子交联作用使CS/CMCS载药止血膜的拉伸强度提高55%,而断裂伸长率仅降低24%.止血评价结果表明经丙三醇改性的CS/CMCS=8/2止血膜均能使血液发生分离的时间明显缩短,并具有促使血液凝结形成黑色血块的能力.     

食用色素对壳聚糖改性纤维染色性能的研究

为了研制符合食品包装要求的彩色防水纸浆模塑制品,选用食用色素对壳聚糖处理后的纸浆纤维进行染色,并在染色纸浆中加入防水剂H,讨论了防水剂质量分数对纸浆纤维防水效果和染色效果的影响。结果表明,染色温度为60℃,染料用量为0.6%(对绝干浆质量),染浴pH=3.5的条件下染色效果较好。结合生产实际,可进行常温染色,上染率达71.43%,褪色率为7.12%。防水剂的加入除能明显提高纸模制品的湿环压强度外还能改善其染色效果,添加量为5%(对绝干浆质量)时,纸模可达到较好的湿环压强度,上染率可提高到79.30%,褪色率降低为0.31%。     

Novel fluorescence sensor based on covalent immobilization of 3-amino-9-ethylcarbazole via electrostatically assembled gold nanoparticle layer

A novel technique of immobilizing indicator dyes by electrostatic adsorption and covalent bonding to fabricate optical sensors was developed. 3-Amino-9-ethylcarbazole (AEC) was attached to the outmost surface of quartz glass slide via aminosilanizing the slide, crosslinking chitosan, adsorbing Au nanoparticle, self-assembling HS(CH₂)₁₁OH, and coupling AEC. Thus, an AEC-immobilized optical sensor was obtained. The sensor exhibits a wide linear response range from 7.0×10⁻⁷ to 1.0×10⁻⁴ mol/L and a correlation coefficient of 0.995 9 for the detection of 2-nitrophenol. The detection limit and response time of the sensor are 1.0×10⁻⁷ mol/L and less than 10 s, respectively. The fluorescence intensity of the used sensor can be restored to the blank value by simply rinsing with blank buffer. A very effective matrix for immobilizing indicator dye is provided by the proposed technique, which is adaptable to other indicator dyes with amino groups besides AEC. Foundation item: Project(20775010) supported by the National Natural Science Foundation of China; Project(208095) supported by the Key Project of Ministry of Education, China; Project(07A006) supported by the Scientific Research Fund of Hunan Provincial Education Department, China; Project(07JJ3020) supported by Hunan Provincial Natural Science Foundation of China