壳聚糖-多巴胺/蒙脱土复合膜的制备和抗水性能研究

采用京尼平（genipin）作为交联剂制备得到壳聚糖-多巴胺/蒙脱土复合膜。结果表明,京尼平交联的多巴胺添加到壳聚糖/蒙脱土中制备得到的壳聚糖-多巴胺/蒙脱土复合膜的抗水性能显著增强。同时,对不同pH值（2、4.5、9和11）水溶液的抗水性能也明显增强。复合膜的强度性能随多巴胺用量增加而增大。XRD结果表明,京尼平的加入使壳聚糖和蒙脱土分子重新排列。抗水性能的增强与京尼平交联后形成的聚多巴胺密切相关。这对开发壳聚糖生物基膜材料提供了有价值的理论基础和实践意义。     

无机交联蒙脱土在催化反应中的应用

对近年来Al、Ti、Fe、Zr-交联蒙脱土用于烷烃芳构化、酯化、选择还原NOx、光催化氧化分解有机污染物、Friedel-Crafts反应和醇胺化等反应的研究结果进行了综述。为进一步提高蒙脱土的热稳定性和催化性能，在单一交联蒙脱土研究的基础上，制备多元交联蒙脱土将成为今后的研究重点。     

环氧树脂/蒙脱土纳米复合材料性能的研究

用一种新型的热稳定性较好的改性剂2，2’-二[4-(4-氨基苯氧基)苯基]-丙烷(BAPP)改性钠基蒙脱土，再与环氧树脂进行纳米复合制备了环氧树脂／蒙脱土纳米复合材料。讨论了蒙脱土用量对环氧树脂／蒙脱土纳米复合材料性能的影响，并对其结构和性能进行了表征和测试。结果表明：改性使蒙脱土层间距变大，制备出的环氧树脂／蒙脱土纳米复合材料剥离结构较好，环氧树脂／蒙脱土纳米复合材料的玻璃化转变温度和动态储能模量随改性蒙脱土用量的增加呈现较好的递增趋势。     

交联聚乙烯/丙烯酸/蒙脱土纳米复合材料的制备与表征

在制备交联聚乙烯／蒙脱土纳米复合材料的过程中,利用交联聚乙烯的特征,通过在与蒙脱土熔融复合的过程中加入单体丙烯酸作为相容剂,制得交联聚乙烯／蒙脱土纳米复合材料。用XRD、TEM进行表征,并对材料的力学性能进行测试。结果显示：复合材料的拉伸强度与原基材相比有所上升,而冲击强度有所下降。     

交联蒙脱土催化剂底面间距的测定

通过X射线衍射测定了一系列羟基混合金属柱交联蒙脱土的底面间距,并考察了制备条件、焙烧温度等对交联蒙脱土底面间距的影响。结果发现蒙脱土经交联之后底面间距有较大的增加;采用共混法、焙烧温度在500℃时制得的催化剂具有较大的底面间距;另外,羟基混合金属柱中各种金属离子的比例对交联蒙脱土的底面间距有较大的影响。     

表面活性剂改性的铝交联蒙脱土的表征及催化性能

以聚乙烯醇为支撑前体,合成了一类新型的表面活剂改性的铝交联蒙脱土。通过ＸＲＤ,低温Ｎ２脱吸附分析,骨架振动红外光谱等手段的表征及对催化转化柴油为汽油的测试,表明热稳定性与催化活性传统的铝交联蒙脱土都有显著提高。     

聚乙烯醇/改性纳米蒙脱土复合材料的制备与性能

纳米蒙脱土(MMT)用十六烷基三甲基溴化铵进行改性制得有机改性的MMT(OMMT),用其作为聚乙烯醇(PVAL)的改性材料,采用溶液共混、流涎成膜制得PLA/OMMT复合材料,考察了OMMT的用量对PVAL复合材料性能的影响。用傅立叶变换红外光谱(FTIR)仪、差示扫描量热仪、扫描电子显微镜、X射线衍射仪、万能力学试验机等对复合材料性能及结构进行表征和分析。结果表明,FTIR显示十六烷基三甲基溴化铵成功进入MMT结构中,OMMT成功制得;随着OMMT添加量的增加,复合材料热稳定性提高,断裂伸长率降低,拉伸强度呈现先增加后降低趋势,当其含量为9%时达到最大;SEM显示OMMT含量9%时,OMMT与PVAL相容性最好,表面光滑,含量再增加,出现团聚现象,力学性能受到影响。     

环氧树脂/蒙脱土纳米复合材料的制备及性能

实验采用长链烷基胺对原始蒙脱土进行有机化处理，再利用环氧树脂对有机蒙脱土插层，制得环氧树脂，蒙脱土纳米复合材料。实验表明，改性环氧树脂的冲击强度有所提高。     

聚丙烯／蒙脱土复合材料热稳性能的研究

文章通过熔融共混法制备了聚丙烯／蒙脱土复合材料,对蒙脱土的分散状态进行了表征,并对复合材料的热稳性进行了研究,结果表孵,蒙脱土可以防止氧气的渗入,同时蒙脱土片层的阻隔作用也可以阻挡一些低分子降解产物从体系中逸出,廷缓热氧化降解的进行,但是在制备有机蒙脱土中常用的蒙脱土有机改性剂（烷基季铵盐）会对聚丙烯的热稳性产生不利影响。     

铝交联蒙脱土结构影响因素的研究

利用电镜、比表面仪和X射线衍射分析方法表征了制备的铝交联蒙脱土。结果表明,OH^-与Al^3+物质的量比、焙烧温度和酸化浓度对交联蒙脱土结构有一定影响,交联剂陈化时间对酸化交联蒙脱土的收率也有影响,最佳条件:n(OH^-)∶n(Al³⁺)=2.2,焙烧温度65 ℃,酸化浓度5%～20%,交联剂陈化时间1.5天。     

壳聚糖基聚电解质复合膜的制备及性能

为了克服壳聚糖薄膜力学强度差和在体液内降解太快的缺陷, 首先用"一步法"合成了—COOH含量及疏水性可控的苹果酸与乳酸共聚物(PML), 再将共聚物与壳聚糖(CS)复合, 通过溶液浇铸-挥发的方法制备改性复合薄膜。通过红外(FT-IR)、热重分析(TGA)、力学性能测试、降解实验及体外细胞毒性实验等方法对复合膜进行分析, 研究L-苹果酸(MA)与D,L-乳酸(LA)的投料比(n_MA:n_LA)对复合膜性能的影响。结果显示:当n_MA:n_LA为1:1.5时, 该共聚物与CS的复合膜拉伸强度达到54.8MPa, 断裂伸长率为10.7%, 质量损失50%所需时间为28天, 细胞相对增殖率为98.7%。研究表明:通过共聚物与壳聚糖之间的聚电解质相互作用, 有效形成了结构均匀、性能改善的薄膜, 复合膜的柔韧性提高, 降解时间适当延长, 性能可由共聚物的投料比来调节。复合膜无细胞毒性, 生物相容性好, 作为手术后防组织粘连材料具有光明的应用前景。     

壳聚糖/淀粉共混膜的制备及掺杂螺吡喃膜的光致变色性能

以壳聚糖和土豆淀粉为原料,采用溶液共混与流延成膜工艺,制备了壳聚糖/淀粉共混薄膜,探讨了共混薄膜的最佳制备条件,并研究了掺杂螺吡喃的壳聚糖/淀粉共混薄膜的光学性能。结果表明:当壳聚糖与淀粉质量比为1∶1,乙二醛用量为2.0 g,甘油用量为2.0 mL,温度为65℃时,制备的壳聚糖/淀粉共混薄膜性能最佳;添加螺吡喃的壳聚糖/淀粉共混薄膜具有光致变色现象,且随着紫外光照射时间的延长,颜色加深。     

Preparation and adsorption properties of metal ions of crosslinked chitosan azacrown ethers

The novel azacrown ether chitosan derivatives (CCAE‐I, CCAE‐II) were prepared by reaction between crosslinked chitosan with epoxy‐activated azacrown ethers. Their structures were confirmed by elemental FTIR spectra analysis and X‐ray diffraction analysis. The adsorption and selectivity properties of the crosslinked chitosan azacrown ethers for Pb²⁺, Cu²⁺, Cr³⁺, Cd²⁺, and Hg²⁺ were also investigated. The experimental results showed that they have high adsorption capacity for Cu²⁺, Cd²⁺, and Hg²⁺. The adsorption capacity of CCAE‐II is higher than CCAE‐I for Cd²⁺ and Hg²⁺. The selectivity properties of CCAE are better than chitosan and crosslinked chitosan. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 3053–3058, 1999     

Preparation and characterization of chitosan films,crosslinked with symmetric aromatic dianhydrides to achieve enhanced thermal properties

This study has developed a new generation of crosslinked chitosan‐based films using symmetric aromatic dianhydrides as crosslinking agents. The formation of the dianhydride‐crosslinked chitosan hydrogel films was confirmed using Fourier transform infrared and solid‐state ¹³C NMR spectral analyses. The films obtained from these derivatives were characterized by their thermal, swelling and hydrophilic properties. The results showed that introducing a cyclic imide moiety into the chitosan matrices played a significant role in enhancing the thermal properties of these chitosan films. It was found that even at high levels of substitution, thermal stability of the studied chitosan derivatives was improved, in spite of a reduction in crystallinity. Heterocyclic imide linkages produced networks that were insoluble in both acidic and alkaline media but allowed swelling in aqueous media. An increase in the hydrophobicity of the chitosan film surfaces was observed after introduction of the cyclic imide moiety. These engineered films produced noteworthy results concerning their thermal and swelling properties. There is a need to further investigate these films for drug delivery and biomaterials applications. © 2014 Society of Chemical Industry     

蒙脱石/TiO2复合材料制备及其光催化性能研究

以蒙脱土和钛酸丁酯为原料,采用溶胶凝胶法制备出蒙脱石/TiO2复合材料,利用XRD、SEM、光催化亚甲基蓝溶液对其物相组成、晶体结构、微观结构和光催化性能进行了研究.结果表明:TiO2以锐钛矿相分布于蒙脱石的层间域和表面,并使蒙脱石d001有不同程度的增大.蒙脱石/TiO2复合材料的加入量和Ti/蒙脱石比值、亚甲基蓝溶液的初始质量浓度对蒙脱石/TiO2复合材料的吸附和光催化效率均有影响.     

硅层柱蒙脱土的制备

以钠基蒙脱土为原料,制备了硅层柱蒙脱土,并采用XRD、N₂吸附-脱附分析和吡啶吸附红外光谱进行表征,研究硅层柱蒙脱土的水热稳定性及表面酸性。结果表明,硅层柱蒙脱土以中强酸位和强酸位为主,弱酸位较少。硅层柱蒙脱土在800 ℃焙烧仍保留片层结构不坍塌,600 ℃经过100%水蒸汽水热处理2 h后片层结构坍塌。     

磺化交联壳聚糖树脂固体酸催化剂的制备及表征

引言壳聚糖是自然界的第二大天然有机物甲壳素的脱乙酰产物,具有来源丰富、环境友好的优点。壳聚糖分子同时含有活泼的氨基和羟基,可通过烷基化、酯化、希夫碱等反应进行化学修饰生成具有各种不同新型结构和功能的衍生物[1]。近年来壳聚糖在催化领域的应用受到了越来越多的关注,功能化     

Synthesis and adsorption properties for metal ions of crosslinked chitosan acetate crown ethers

Two novel chitosan derivatives—crosslinked chitosan dibenzo‐16‐c‐5 acetate crown ether (CCTS‐1) and crosslinked chitosan 3,5‐di‐tert‐butyl dibenzo‐14‐c‐4 diacetate crown ether (CCTS‐2)—were synthesized by the reaction of crosslinked chitosan with dibenzo‐16‐c‐5 chloracetate crown ether and 3,5‐di‐tert‐butyl dibenzo‐14‐c‐4 dichloracetate crown ether with the intent of forming polymers that could be used in hazardous waste remediation as toxic metal‐binding agents in aqueous environments. Their structures were confirmed with elemental analysis, infrared spectral analysis, and X‐ray diffraction analysis. In the infrared spectra of CCTS‐1 and CCTS‐2, the characteristic peaks of aromatic backbone vibration appeared at 1595 cm⁻¹ and 1500 cm⁻¹; the intensity of the N H and O H stretching vibration in the region of 3150–3200 cm⁻¹ decreased greatly. The X‐ray diffraction analysis showed that the peak at 2θ = 20° decreased greatly in CCTS‐1 and CCTS‐2. The adsorption and selectivity properties of CCTS‐1 and CCTS‐2 for Pb²⁺, Cu²⁺, Cr³⁺, and Ni²⁺ were studied. Experimental results showed that the two crosslinked chitosan derivatives had not only good adsorption capacities for Pb²⁺, Cu²⁺, but also high selectivity for Pb²⁺, Cu²⁺ in the coexistence of Ni²⁺. For aqueous systems containing Pb²⁺, Ni²⁺, or Cu²⁺, Ni²⁺, CCTS‐1 only adsorbed Pb²⁺ or Cu²⁺. For aqueous systems containing Pb²⁺, Cr²⁺ and Ni²⁺, CCTS‐2 had high adsorption and selectivity properties for Pb²⁺. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 2069–2074, 1999     

凝聚共沉法制备的蒙脱土／天然橡胶纳米复合材料及其性能研究

以新鲜胶乳为主体材料,有机改性蒙脱土为填料,用凝聚共沉法制备了蒙脱土／天然橡胶复合材料,研究了复合材料的物理性能、动态力学性能及其热稳定性。结果表明,在天然橡胶中加入少量（3％-5％）的纳米蒙脱土,可以使橡胶的定伸应力、拉伸强度等性能大幅度提高,动态力学性能和耐热稳定性得到明显改善。     

Preparation and adsorption behavior for metal of chitosan crosslinked by dihydroxy azacrown ether

A new type of crosslinked chitosan was prepared using Dihydroxy azacrown ether as the crosslinking agent. Its structure was confirmed by elemental analysis, Fourier transform infrared (FTIR) spectra analysis, solid‐state ¹³C nuclear magnetic resonance (NMR) analysis, and X‐ray diffraction analysis. Its static adsorption properties for Ag⁺, Cd²⁺, Hg²⁺, and Co²⁺ were studied. The experimental results showed that the Dihydroxy azacrown ether crosslinked chitosan has good adsorption capacities and high selectivity for adsorption of Ag⁺ with the coexistence of Hg²⁺ and Co²⁺. The selectivity coefficients of crosslinked chitosan are k/ = 5.47, k/ = 4.64, respectively. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 530–535, 2002