添加LDH-ZnO的海藻酸钠基抗菌复合材料研究综述

目的 介绍海藻酸钠基抗菌复合材料的抗菌机理、特点以及在食品包装方面的应用。方法 重点阐述海藻酸钠的成膜机理、纳米氧化锌的抗菌机理,以及具有特殊层状结构的无机功能材料水滑石的抑菌性能,利用在不同改性方法下水滑石与氧化锌结合形成的增强抗菌结构,探究以海藻酸钠为基材制成的海藻酸钠/水滑石/纳米氧化锌复合膜体系的力学、阻隔和抗菌等性能。结论 绿色食品包装材料在现实生活中倍受关注,将海藻酸钠(能完全生物降解,具有良好的生物相容性和热稳定性的环境友好型材料)与水滑石-氧化锌抗菌剂结合,以增强抗菌复合材料的综合性能,符合国内外研究和开发新型抗菌材料的趋势。     

水滑石@凹凸棒石的制备及其吸附性能

采用共沉淀法制备镁铝水滑石,探讨化学沉淀法和物理球磨法两种复合方式对水滑石@凹凸棒石复合材料物相、微观结构和吸附性能的影响,利用X射线衍射(XRD)仪、扫描电镜(SEM)、傅里叶红外光谱(FTIR)仪对反应产物进行表征.结果表明,物理球磨法制备的复合材料对盐酸四环素吸附效果较好.当凹凸棒石用量为水滑石质量70％时,凹凸...     

室温超快速制备HKUST-1及其对甲苯的吸附性能

以硝酸铜和均苯三甲酸为原料,通过水滑石法室温10 s快速制备了一种金属有机骨架材料HKUST-1,对其进行了XRD、SEM和N2吸附表征,测定了甲苯在HKUST-1上的吸附等温线、动力学和吸附-脱附循环性能.结果表明,水滑石的添加使HKUST-1可在室温10 s内快速合成,HKUST-1的BET比表面积达到2170.7...     

改性类水滑石的制备及其去除溶液中Eu(Ⅲ)和U(Ⅵ)

通过水热合成法成功地制备了丙三醇改性Ni/Al型水滑石(GMH),并通过批量处理法和静态吸附法考察了在固体投加量、溶液pH、离子强度、腐殖酸、接触时间和温度等因素影响下,溶液中Eu(Ⅲ)和U(Ⅵ)在GMH上的吸附行为。采用扫描电镜(SEM)、红外光谱(FTIR)、X射线衍射(XRD)等表征手段对材料吸附前后进行分析,结合吸附动力学和热力学模型对吸附机理进行探讨。结果表明,溶液pH值对Eu(Ⅲ)和U(Ⅵ)在GMH上的吸附行为影响显著,在pH=7.0左右时吸附率达到最大;准二级动力学模型和Langmuir等温线模型可以很好地描述Eu(Ⅲ)和U(Ⅵ)在GMH上的吸附过程,且此过程是自发的、吸热的过程;实验条件下,GMH对溶液中的Eu(Ⅲ)和U(Ⅵ)的最大理论吸附量分别为511 mg/g和441 mg/g;GMH对溶液中Eu(Ⅲ)的吸附主要是通过静电相互作用、内层表面络合以及离子交换相互作用实现;而对U(Ⅵ)的吸附主要是通过静电相互作用和内层表面络合作用实现的。实验表明,合成材料在含低放废水的有效净化和修复方面具有很大的应用前景。     

High-speed CO2 transport channel containing carboxymethyl chitosan/hydrotalcite membrane for CO2 separation

A comprehensive understanding of carboxymethyl chitosan (CMC)-based mixed matrix membrane (MMM) has been critically investigated. The present work elaborates the compatibility of hydrotalcite (HT) and CMC in terms of CO₂ separation application. Various spectroscopic and microscopic techniques have been utilized to characterize the respective properties of the prepared membrane. The temperature stability and moisture retention behavior of the membrane recognized itself as the flue gas separation membrane. The CO₂/N₂ separation experiment was performed on the MMM at different temperature (60–110 °C) and sweep/feed water flow to the saturator ratio (0.33 to 3). The membrane exhibited the optimum CO₂ permeance of 70 GPU at 90°C pertaining to water flow ratio of 2.33 (sweep/feed). The CO₂/N₂ selectivity observed at that same operating condition was 13. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48715.     

Effects of KF Loading on Mg–Al Mixed Oxides for the Selective Synthesis of Trimethylolpropane Triesters

A series of Mg–Al hydrotalcites (HTCs) calcined at different temperatures were evaluated for their suitability as solid base catalysts for the selective synthesis of trimethylolpropane triesters (TMPTEs) via transesterification of trimethylolpropane (TMP) with a mixture of C₈–C₁₀ fatty acid methyl esters (FAMEs). The effect of potassium fluoride (KF) loading of the calcined HTCs on the physicochemical and catalytic properties of the materials attained was ascertained. Using a 5?wt% catalyst loading and a FAME:TMP molar ratio of 3.5:1 at 170°C for 8?h, the Mg–Al mixed oxide obtained by calcining HTC at 500°C (HTC-500) gave the highest TMPTE selectivity and FAME conversion. Impregnating HTC-500 with 10?wt% KF (KF/HTC-500) generated strongly basic KMgF₃, KOH, K₂O, and coordinatively unsaturated F^? sites. The FAME conversion and TMPTE yield obtained over different HTC and KF/HTC-500 catalysts depended on their total basicity, where a basic strength of 15?H_{_}?3, a common homogeneous base for the polyol ester production.     

层状双金属氢氧化物的合成与应用

层状双金属氢氧化物（LDHs）是近来受到广泛关注的一类新型固体催化材料，具有碱性、氧化还原性和层间阴离子可交换性。本文综述了近年来层状双金属氢氧化物合成与应用方面的研究进展。主要包括LDHs及柱撑LDHs的合成方法，LDHs及其焙烧产物在碱催化、氧化还原催化和催化剂载体、功能材料、医药等领域的应用。     

Structural Reversibility of a Ternary CuO-ZnO-Al2O3 ex Hydrotalcite-Containing Material During Wet Pd Impregnation

A Cu-Zn-Al precursor was synthesized by coprecipitation of the corresponding cations with sodium carbonate at constant pH and temperature. CuO-ZnO-Al₂O₃ composite oxide support was obtained by calcination (673 K) of the Cu-Zn-Al precursor. Two palladium-modified CuO-ZnO-Al₂O₃ samples were prepared by impregnation of the mixed-oxide support and further calcination (673 K). The presence of remaining CO₃ ^2- anions in the CuO-ZnO-Al₂O₃ mixed oxide, as a result of incomplete Cu-Zn hydrotalcite phase decomposition, and the hydrothermal-like treatment during the Pd impregnation step, allow the partial reconstruction of the Cu-Zn hydrotalcite-type structure (memory effect). In addition, an enhancement in the CuO crystallinity was obtained for the Pd-modified oxides. A detailed characterization revealed that the hydrotalcite restoration enhances the crystallinity of the copper oxide as a consequence of a crystalline rearrangement of this oxidic phase.     

水滑石/红磷/磷酸三甲苯酯复配体系在丁苯橡胶阻燃中的应用

通过对比不同品种的无机阻燃剂对丁苯橡胶阻燃性能和力学性能的影响,在相同条件下得出水滑石的阻燃效果较好.为提高水滑石对丁苯橡胶的阻燃性能,采用以水滑石、微胶囊红磷、磷酸三甲苯酯的复配体系为阻燃体系.研究复配体系中各阻燃剂的用量对丁苯橡胶机械性能和阻燃性能的影响.结果表明：添加80份水滑石,10份微囊红磷和10份磷酸三甲苯酯时丁苯橡胶的力学性能和阻燃性能都较好,氧指数达35%.     

水滑石类材料碱性催化性能的应用研究

以绿色化学为基础,综述了类水滑石及其以类水滑石为前驱体衍生的复合氧化物作为一类优异的固体碱催化剂应用于醇醛缩合、克诺文诺盖尔(Knoevenagel)缩合、麦克尔(M ichael)加成以及酯交换等反应的最新研究进展。预测了水滑石类材料由于具有特殊的结构和性质必将在环境友好的催化工业体系中扮演越来越重要的角色。