Electrically conductive aluminosilicate/graphene nanocomposite

Highly electrically conductive ceramic material based on aluminosilicate/graphene nanocomposite has been prepared by high pressure (400 MPa) compaction of montmorillonite intercalated with polyaniline followed with the high temperature (1400 °C) treatment in argon atmosphere. Tablets pressed from polyaniline/montmorillonite intercalate exhibits strong texture due to the disk-shaped montmorillonite particles and, consequently, the high anisotropy in conductivity. The high temperature induced phase transformation of montmorillonite into cristobalite and mullite preserved the aluminosilicate layered structure and created good conditions for formation of graphene sheets from polyaniline layers intercalated in montmorillonite. Therefore, the texture and anisotropy in conductivity remain preserved in resulting aluminosilicate/graphene tablets, while the in-plane conductivity in aluminosilicate/graphene tablets is 23,000× higher than the conductivity of uncalcined polyaniline/montmorillonite tablets. Simple fabrication method of aluminosilicate/graphene tablets is very promising for the manufacturing of the electrically conductive and tough ceramic material, which can be exposed to corrosive environment as well as to high temperatures.     

复合改性蒙脱土在污水处理中的应用研究进展

随着经济社会的发展，污水处理问题已成为人们关注的热点。蒙脱土因孔结构丰富、储量丰富且廉价易得而被广泛用于污水处理领域，目前关于蒙脱土吸附材料的研究多采用酸改性、有机改性等于单一改性手段提升其吸附能力，但单一改性蒙脱土存在功能单一、活性较差等问题。诸多研究者将目光集中于复合改性，文章对复合改性蒙脱土，酸-有机改性、无机-有机改性和有机阴离子-阳离子活性剂改性等的研究进展进行了综述，并对复合改性蒙脱土的制备过程和吸附机理进行了分析。提出今后复合蒙脱土研究的主要方向是合成可利用多种方式实现对所有污染物的无差别处理且易于从溶液中分离再生的蒙脱土，如合成既有吸附性，又有光催化和Fenton氧化能力的复合改性蒙脱土，以期为蒙脱土在实际污水处理中提供一定的理论参考。     

羧甲基纤维素/蒙脱土纳米复合材料对刚果红染料的吸附及解吸性能

用X 射线衍射、透射电镜和扫描电镜对羧甲基纤维素/蒙脱土纳米复合材料的结构进行表征。采用溶液插层复合法制备纳米复合材料,探讨不同羧甲基纤维素与蒙脱土质量比、反应时间和反应温度对纳米复合材料吸附刚果红染料吸附量的影响,并初步研究了纳米复合材料的解吸性能。亚微观观察表明：羧甲基纤维素通过破坏蒙脱土的晶体结构插层进入蒙脱土层间,形成插层-剥离型纳米复合材料;当羧甲基纤维素与蒙脱土质量比为1∶1,反应时间为6 h,反应温度为60℃时,纳米复合材料对刚果红染料的吸附量最大,可达50.42 mg·g-1;当解吸试剂氢氧化钠浓度为0.01 mol·L-1时,超声波解吸50 min的纳米复合材料脱附率可达80.17%。     

蒙脱土负载钴(Ⅱ)-8羟基喹啉的制备及催化性能研究

采用离子交换和配位合成方法,通过配位键将配体引入金属蒙脱土层间,制备了Co(Ⅱ)-8Q/MMT复合催化材料,用IR和XRD分析了催化材料的结构,考察了催化剂催化氧化性能.实验结果表明,层间距增大0.332 nm,表明配体进入金属蒙脱土的片层间;在分子氧的氧化作用下,催化氧化苯乙烯的转化率达到42.3%.     

有机蒙脱石增强环氧树脂纳米复合材料的研究

介绍以有机蒙脱石作为增强组分的环氧树脂纳米复合材料的制备及其性能表征。结果表明,十六胺处理的蒙脱石层离以1－100nm尺度分散于环氧树脂基体中,复合材料的物性得到提高,当蒙脱石含量比在3％时,马丁耐热提高9℃,冲击强度提高了122％,但进一步增加蒙脱石的含量比,上述两性能不升反降。     

NBR/Zn(MAA)2/蒙脱土纳米复合材料的研究

研究NBR／基丙烯酸锌[Zn(MAA)2]／蒙脱土纳米复合材料的性能。结果表明，Zn(MAA)2可以通过原位聚合反应在与NBR发生接枝交联的同时，实现对蒙脱土的插层，用该方法制备的NBR／Zn(MAA)2／蒙脱土纳米复合材料的物理性能优异，含有有机改性蒙脱土HMMT和USM的复合材料性能更为突出，且具有一定的透明性。     

蒙脱土负载型固体酸催化剂的烷基化性能与结构研究

以酸化后蒙脱土为载体，采用浸渍蒸发法制备了环境友好的蒙脱土负载znCl2型固体酸催化剂。研究了蒙脱土酸化处理、ZnCl2负载量及活化温度对催化剂烷基化活性的影响，并初步考察了催化剂的稳定性，比较了几种不同酸催化剂的烷基化活性。利用XRD、BET、TG—DTA、吡啶吸附FTIR对催化剂的结构进行了表征和测定；结果表明，蒙脱土酸化处理后形成的孔道有利于负载ZnCl2，ZnCl2与蒙脱土的羟基之间存在着化学键合，经活化后转化成Zn(0H)C1。蒙脱土负载ZnCl2后明显地提高蒙脱土表面的总酸量，催化剂活性与其表面总酸量之间有关，催化剂表面L酸与B酸的共存有利于其烷基化活性的提高。实验条件下，蒙脱土负载ZnCl2型催化剂在苯与氯节的烷基化反应中表现出较高的催化活性，二苯甲烷的收率最高可达83．6％。与其它Lewis酸试剂及酸化蒙脱土相比，蒙脱土负载型催化剂催化活性大有提高。     

Effect of hydroxy-aluminium species on the sorption and interlayering of albumin onto montmorillonite

Proteins interact with soluble OH–Al species or Al precipitation products forming organo-mineral complexes with different chemical and physico-chemical properties. We studied the effect of pH, cation saturating the clays, presence of OH–Al species and order of component (OH–Al species, albumin and montmorillonite) addition on the amounts of proteinic molecules adsorbed on montmorillonite and the possible interlayering of OH–Al–protein complexes. Albumin molecules were very well intercalated into the interlayers of Na-montmorillonites, but very poor or no intercalation was observed for Mg-saturated montmorillonite and for an Al(OH)_x-montmorillonite (chlorite-like) complex.We have found that the amount of albumin sorbed on the external and interlamellar spaces of montmorillonite in the presence of OH–Al species was influenced by the sequence of addition of albumin (Alb), OH–Al species (Al) and montmorillonite (Mt). Complexes were prepared by mixing: (i) Al+Mt before Alb; (ii) Al+Alb before Mt; and (iii) Alb+Mt before Al. When albumin was added to montmorillonite before OH–Al species (Alb+Mt before Al complexes) proteinic molecules were able to penetrate more easily into the interlayers of montmorillonite. On the contrary, when OH–Al species were initially added to the clay (Al+Mt before Alb complexes), they were previously interlayered and consequently prevented the intercalation of the proteinic molecules. Finally, when OH–Al species and proteins were added to the clay as a mixture (Al+Alb before Mt complexes), large OH–Al–protein polymers formed, which were only partially intercalated into the interlamellar spaces of the clay. In all the complexes, the amounts of proteinic molecules sorbed usually increased by increasing the pH.     

蒙脱土/水基聚氨酯纳米复合材料的动态力学分析Ⅰ:离子含量和热处理的影响

以接枝磺酸钠聚己二酸1,4-丁二醇酯二醇、Na基蒙脱土等为原料制备了蒙脱土／水基聚氨酯纳米复合物,并通过研究离子含量和热处理条件对其膜动态力学性能的影响,分析了它们的相态结构与组成及后处理条件间的内在联系。结果表明,蒙脱土的存在妨碍了聚氨酯分子链离子间物理交联的形成,减弱了离子含量变化和热处理对其聚集态结构的影响。另外,还通过Haplin-Tai-Nielsen公式研究了不同离子含量和热处理条件下纳米复合物中蒙脱土的分散状况。     

Cyanate ester polymerization catalysis by layered-silicates

This work examines the effect of Na montmorillonite (Na MMT) and cation exchanged layered montmorillonite on the polymerization of a cyanate ester monomer (1,1-bis(4-cyanatophenyl)ethane). The cyanate ester polymerization reaction is examined using a traditional catalyst and several montmorillonites. Thermal properties of the liquid monomer mixtures and final polymers were investigated, along with the montmorillonite structural changes that occur during the various stages of polymerization. It was found that Na montmorillonite catalyzed the polymerization reaction and that the catalytic activity increased upon sodium cation exchange in the montmorillonite gallery. Montmorillonite catalyzed systems were found to have superior properties (cross-link homogeneity and extent of polymerization) compared to traditionally catalyzed cyanate ester-montmorillonite polymers. Evidence suggests that the montmorillonite structure is a mixture of exfoliated layers and intercalated tactoids. The intercalated montmorillonite was found to undergo a two-step layer expansion process beginning with monomer permeation into the gallery, followed by expansion possibly caused by monomer/polymer reorientation within the gallery.     

碱对蒙脱土与分子筛复合的影响

考察了蒙脱土与沸石分子筛复合过程中碱的影响。在蒙脱土与Y型分子筛的复合过程中,由于体系中氢氧化钠的浓度较大（1%～1.5%）,蒙脱土在氢氧化钠、水玻璃和铝酸钠的共同作用下发生了溶蚀作用,使得蒙脱土结构中的部分硅、铝进入到凝胶溶液当中,改变了凝胶溶液的硅铝比,这一硅铝比超出了生成Y型分子筛所需的相区,形成了新的晶体结构。在蒙脱土与β分子筛进行复合时,体系的碱浓度较小（约0.16%）,且采用白炭黑替代水玻璃用作硅源。通过用XRD对产物进行表征发现,产物中同时拥有β分子筛与蒙脱土的特征衍射峰。     

掺杂/改性蒙脱土的研究进展及应用

作为矿物材料之一的蒙脱土以其优越的物理、化学特性而倍受研究者的青睐。本文介绍了蒙脱土的结构和性质,对蒙脱土的有机改性、无机改性、有机-无机复合改性及掺杂方法作了论述,并对掺杂/改性蒙脱土在废水处理、电化学、纳米复合材料、催化材料方面上的应用作了概括介绍。     

Preparation and characterization of PVA/OMMT composites

In this study, polyvinyl alcohol/organically modified montmorillonite (HDA/MMT; organoclay) composite was prepared for the intercalation processes. Firstly, the rheological behavior of aqueous montmorillonite dispersions was investigated as a function of solid content. Hexadecylamine (HDA) was added to the montmorillonite dispersion (2%, w/w) in different concentrations in the range of 5 × 10^?4 – 9 × 10^?3 mmol/L. The basal spacing of the organoclay (OMMT) was studied by X‐ray diffraction. The FTIR spectra are obtained from the modified montmorillonite products, which revealed the characteristic absorbencies after treatment with HDA. HDA/MMT/PVA composite, which was produced by the reaction of 1 wt % PVA solution with organoclay complex, is characterized by the rheology, electrokinetic, XRD, FTIR, and SEM techniques. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:2315–2323, 2006     

无机-有机柱撑蒙脱石在工业废水处理中的应用研究

蒙脱石( Montmorillonite)因其具有较大的比表面积、丰富的孔结构及低廉的成本,在众多领域广泛应用。尤其在工业废水处理领域,与传统的吸附剂相比,蒙脱石因其特殊的结构,可以通过无机改性来改善其孔结构、提高其比表面积,从而提高其吸附容量;通过有机改性来改善其表面疏水性,增加对有机分子间的亲和力,为拓展蒙脱石在工业废水处理领域中的应用提供了新思路。本文阐述了蒙脱石的结构、性质以及改性方法,在此基础上,着重归纳了无机-有机柱撑蒙脱石在工业废水处理中的应用研究状况,并对研究前景进行了展望。     

有机化蒙脱土改性PET研究

用长链季铵盐和聚乙二醇(PEG)对蒙脱土进行交换反应,使季铵盐嵌入到蒙脱土的晶层间,使蒙脱土由亲水性变为亲油性;有机化改性后的蒙脱土与聚对苯二甲酸乙二醇酯(PET)熔融插层后可以较大地提高原树脂的耐热性和阻隔性能.     

载铜蒙脱石的制备与表征

以蒙脱石和硫酸铜为主要原料,制备载铜蒙脱石。比较载铜前后蒙脱石的晶体结构和表面特性。结果表明：铜主要是以水合阳离子的形式,以离子交换的方式进入蒙脱石品格层间,还有少量铜以化学吸附的形式进入Si-O四面体和Al-O八面体的微孔中。与蒙脱石相比,载铜后的蒙脱石总比表面积、微孔比表面积、微孔体积减少,而离子交换容量、外比表面积、孔体积和孔径增大。另外,载铜蒙脱石的总电荷、层间电荷、端面电荷和zeta电位的绝对值均低于蒙脱石,表明所载铜降低了粘土矿物质的负电荷。     

聚碳酸酯生产中三乙回收胺的研究

采用盐酸洗涤聚碳酸酯的二氯甲烷溶液,有机相中的三乙胺转化为盐酸盐溶于水中。盐酸洗液套用后,蒙脱土吸附处理套用后盐酸洗液中富集的三乙胺盐酸盐,再对该蒙脱土进行碱化、精馏回收三乙胺。该工艺增加了盐酸洗液的套用次数,减少了酸洗液总废水量。三乙胺回收率达70%。     

高模量聚丙烯专用料的开发

通过在聚丙烯中添加纳米蒙脱土的改性方法,开发了高模量聚丙烯专用料。着重研究了蒙脱土活化处理及加工条件等对专用料性能的影响。结果表明,在采用蒙脱石质量分数为75%的普通蒙脱土时,专用料弯曲模量提高60%以上,冲击强度提高一倍,回缩率降低35%,并且加工性能良好。     

Clay-activated transformation of humic acid at high pressure and temperature

The hydrothermal transformation of humic acid in the presence of montmorillonite has been investigated. At a pressure of 100 MPa and a temperature of 300°C, humic acid was transformed into a coal-like macromolecule after 10 days. Besides being enriched in hydrogen and aromatic rings, the product showed regions of long-range structural order. Hydrothermal treatment in the absence of clay led to extensive decomposition of the humic acid.     

Preparation and Characterization of Polyvinylpyrrolidone/L-leucine Amino Acid–Modified Montmorillonite/Chiral Diacid–Functionalized Mg-Substituted Fluorapatite Nanocomposites by Ultrasonic-Assisted Rapid Process

In this work, the surface of synthetic nanosized Mg-substituted fluorapatite particles was modified with biodegradable diacid N-trimellitylimido-L-leucine as a coupling agent in methanol. Furthermore, different contents of N-trimellitylimido-L-leucine-modified Mg-substituted fluorapatite were doped into polyvinylpyrrolidone/L-leucine-modified montmorillonite material to prepare novel ternary polyvinylpyrrolidone/modified montmorillonite/N-trimellitylimido-L-leucine-Mg-substituted fluorapatite nanocomposites by an efficient sonication process. Nanocomposite containing 5?wt% modified montmorillonite and 3, 5, and 7?wt% N-trimellitylimido-L-leucine-modified Mg-substituted fluorapatite contents were prepared and labeled as polyvinylpyrrolidone/modified montmorillonite/N-trimellitylimido-L-leucine-Mg-substituted fluorapatite 3, polyvinylpyrrolidone/modified montmorillonite/N-trimellitylimido-L-leucine-Mg-substituted fluorapatite 5, and polyvinylpyrrolidone/modified montmorillonite/N-trimellitylimido-L-leucine-Mg-substituted fluorapatite 7, respectively. The structure and morphology of the aforesaid products were characterized by different analytical apparatuses.