苯甲酰胺分子在高岭石层间的成键和取向

利用X射线粉末衍射和Fourier变换红外光谱实验分析了2种高岭石及其苯甲酰胺插层复合物的结构.结构表征与分析表明:复合物的层间距分别扩张到1.437 nm和1.444 nm,苯甲酰胺分子在高岭石层间均呈单分子竖直排列,但与层间表面的倾斜状况不同.在佛山高岭石/苯甲酰胺插层复合物中,氨基和羰基同时参于与内表面羟基的作用;而在苏州高岭石/苯甲酰胺插层复合物中,只有氨基与内表面羟基成键,且苯甲酰胺分子还部分嵌入高岭石的复三方空穴.     

高岭石/甘氨酸插层复合物的制备与表征

通过取代法成功地将甘氨酸插入到高岭石层间，制备出高岭石／甘氨酸插层复合物，XRD显示插层复合物1．0nm出现衍射峰，红外光谱表明甘氨酸分子中的N、O原子与高岭石片层间离子形成了氢键。     

置换插层制备高岭石--甲醇复合物的机理

分别以高岭石--二甲基亚砜插层复合物和高岭石--尿素插层复合物为前驱体,采用多次逐步置换插层方法制备高岭石--甲醇插层复合物。通过X射线衍射和红外光谱测定不同插层阶段产物的结构,对不同前驱体制备高岭石--甲醇插层复合物的置换插层机理进行了探讨。结果表明:前驱体不同,其置换过程行为不一样。以高岭石--二甲基亚砜插层复合物为前驱体,甲醇分子首先以分子状态进入层间,随着置换次数和时间的增长,逐渐以化学键结合于层间,表现为变化较大的层间距;以高岭石--尿素插层复合物为前驱体,甲醇分子直接以化学键结合于层间,表现为比较稳定的层间距。红外光谱研究表明甲醇分子主要与高岭石晶层中的内表面羟基发生作用,形成新的化学键接枝于高岭石层间。     

高岭石-氨基硅烷插层复合物的制备与表征

以高岭石-甲醇(K-M)复合物为前驱体,利用置换法于常温下制备了3种高岭石-氨基硅烷插层复合物。用X射线衍射、Fourier变换红外光谱仪、透射电子显微镜、热分析仪等对复合物进行了表征。结果表明:3种高岭石-氨基硅烷插层复合物的层间距均扩大至2nm以上,插层率都大于95%。3种氨基硅烷分子均和K-M前驱体的甲氧基共同存在于高岭石层间,均呈两层倾斜排列,倾斜程度不同。氨基硅烷的插入破坏了高岭石层间的氢键,加剧了高岭石自身结构中硅氧四面体片层与铝氧八面体片层之间的错位,使得复合物片层出现不同程度的卷曲变形。3种高岭石-氨基硅烷插层复合物的热分解过程均分三步进行:表面水的蒸发及层间甲氧基的脱嵌分解、插层剂氨基硅烷分子的脱嵌、高岭石脱羟基。     

高岭石--烷基胺插层复合物的制备与纳米卷的形成

以张家口高岭土、用二甲基亚砜、甲醇和不同烷基胺为原料,通过插层和置换反应,制备出了高岭石--不同烷基胺(一异丙胺、正丁胺、正己胺、十二胺)插层复合物,并对其结构和形貌进行了表征。结果表明:烷基胺以甲氧基嫁接的高岭石为前驱体进入高岭石层间,使高岭石层间距由0.71nm扩大至1.24～4.23nm。随烷基胺分子碳链的增长,相应的高岭石插层复合物层间距亦增大,结构稳定性增加。烷基胺的插层可使高岭石片层剥离卷曲形成直径为30～100nm、长度为250～2 000nm的纳米管。纳米管的形貌及产率与烷基胺分子结构有关:烷基胺分子碳链越长,纳米卷产率越大,形貌越完整、直径越均一。烷基胺插层进入高岭石层间,不仅极大地降低了高岭石晶层间氢键,而且为高岭石片层向管状卷曲提供了充分自由空间。     

阳离子对醋酸盐插层高岭石影响的研究

采用研磨法制备了高岭石/醋酸钠和高岭石/醋酸钾钠插层复合物,并用XRD、FI-IR、TG-DSC对插层复合物进行表征,探讨了阳离子不同对插层结果的影响.结果表明: K~+、Na~+的不同对插层结果有很大影响,与醋酸钾插层复合物只有一个1.365 nm衍射峰不同,醋酸钠插层复合物,出现了0.979 nm和0.765 nm两个衍射峰,醋酸盐分子在高岭石层间直立取向,阳离子和甲基可能进入到了复三方孔中.     

高岭石有机插层复合材料的研究及应用现状

高岭石是一种层状硅酸盐矿物,有机物可进入其层间形成高岭石有机插层复合物。本文综述了高岭石有机插层复合物的发展及其制备,分析了高岭石插层复合物的插层反应特点和插层影响因素,并概述了该领域目前的研究重点和应用前景。     

高岭石/酒石酸插层复合物的制备与表征

介绍了二甲亚砜(DMSO)取代法制备高岭石/酒石酸(标记为K/T)插层复合物.产物经XRD-6000粉晶衍射和傅立叶变换红外光谱表征.XRD表明:高岭石层间距由0.72 nm扩张到1.09 nm,插层率达50%.红外光谱表明:酒石酸分子的羰基与高岭石的内表面羟基形成了氢键,而羟基与高岭石的硅氧面的氧形成了氢键.酒石酸分子以单分子层平铺于高岭石层间.     

高岭石/苯甲酰胺插层复合物的制备和表征

在60℃下,高岭石与二甲基亚砜反应制备高岭石/二甲基亚砜插层复合物,使用X衍射分析、热分析、红外光谱分析对其进行表征。在140℃下,苯甲酰胺与高岭石/二甲基亚砜插层复合物反应4 d,得到高岭石/苯甲酰胺插层复合物,对其进行表征,然后与高岭石/二甲基亚砜插层复合物进行对比。结果表明：在没有二甲基亚砜作为前驱体的情况下,苯甲酰胺不能与高岭石直接进行反应;高岭石/苯甲酰胺插层复合物结构的稳定性好,是由于苯甲酰胺插层内羰基中的氧原子与高岭石层间表面上的铝硅酸盐形成氢键。     

高岭石-甲醇插层复合物的结构及热分解行为

采用多次置换插层法制得高岭石-甲醇插层复合物,用X射线衍射、傅里叶变换红外光谱、热重和差示扫描量热技术对产物的结构和热分解行为进行了表征.结果表明:甲醇插入到高岭石层间,高岭石层间距由0.71 nm扩大到0.93 nm,插层率为100％.插层复合物中,甲醇分别以与高岭石内表面范德华力结合、氢键键合及嵌入复三方孔穴三种形态存在.在加热过程中,插层复合物分三步分解.第一步分解发生于30～120℃,为层间范德华力结合的甲醇分子的脱嵌过程;第二步发生于120～350℃,是氢键键合的甲醇的脱嵌过程;第三步发生在400～ 600℃,对应于高岭石脱羟基和嵌入高岭石晶格内部的甲醇的脱嵌过程.计算得到复合物体系中高岭石与甲醇的分子摩尔比为1∶0.7,其中以范德华力结合、氢键键合和嵌入复三方孔穴的甲醇的摩尔比为5.2∶11.8∶1.     

Comparison of solution intercalation and melt intercalation of polymer-clay nanocomposites

Polymer-clay nanocomposites of poly(ethylene oxide)/Na-montmorillonite (PEO/MMT) and PEO/organo-modified bentonite (B34) systems prepared via solution intercalation and melt intercalation have been compared by X-ray diffraction and Fourier transform infrared (FTIR) analysis. The gallery size of solution-intercalated hybrids in both PEO/MMT and PEO/B34 systems increases with PEO content up to a plateau level at 15%. However, the gallery size of melt-intercalated PEO/MMT and PEO/B34 hybrid remains the same regardless of the PEO concentration. FTIR analysis shows no difference in spectrum of samples prepared by solution intercalation compared to melt intercalation. The PEO conformation in the PEO/clay intercalated hybrids is concluded to be a distorted helical structure.     

物理插层复合在聚合物/蒙脱土纳米复合材料制备中的应用

描述了物理插层复合的热力学原理,介绍了插层复合中插层剂的种类和聚合物／蒙脱土纳米复合材料的表征方法。综述了近年来国内外应用溶液插层和熔融插层两种物理插层法制备聚合物／蒙脱土纳米复合材料的具体实例。     

聚合物/蒙脱土纳米复合材料的研究进展

综述了聚合物/蒙脱土纳米复合材料的制备、结构类型等,并以尼龙、聚丙烯、聚苯乙烯等聚合物为例,介绍了纳米复合材料的最新研究进展。     

超声波法制备高岭石插层复合物

用超声波法制备了高岭石插层复合物.利用红外光谱、X射线衍射和透射电子显微镜分析了不同产地高岭石结构的差异、插层效果以及它们之间的关系.比较了不同类型插层剂与高岭石的插层产物、插层效果及插层机理.结果表明:相同条件下,多水高岭石(埃洛石)和结构压力大的管状高岭石比普通高岭石更易于插层.在60℃,3 h,超声波条件下,将高岭石/二甲基亚砜(dimethylsulphoxide,DMSO)作为媒介,采用两步插层法快速制备高岭石/乙醇前驱体,但DMSO的插层率优于乙醇的.甲醇钠与苏州高岭石作用后,使部分苏州土片层间剥离.     

Graphite intercalation compound with iodine as the major intercalate

Halogenated graphite CBr_xI_y (1 < y/x < 10) was made by exposing graphite materials to either pure Br₂ or an I₂/Br₂/HBr mixture to initiate the reaction, and then to iodine vapor containing a small amount of Br₂/HBr/IBr to complete the intercalation reaction. Wetting of the graphite materials by the I₂/Br₂/HBr mixture is needed to start the reaction, and a small amount of Br₂/HBr/IBr is needed to complete the charge transfer between iodine and carbon. The interplanar spacings for the graphite materials need to be in the 3.35 to 3.41 Å range. The X-ray diffraction data obtained from the halogenated HOPG indicate that the distance between the two carbon layers containing intercalate is 7.25 Å. Electrical resistivity of the fiber product is from 3 to 6.5 times the pristine value. The presence of a small amount of isoprene rubber in the reaction significantly increased the iodine-to-bromine ratio in the product. In this reaction, rubber is known to generate HBr and to slowly remove bromine from the vapor. The halogenation generally caused a 22% to 25% weight increase. The halogens were found uniformly distributed in the product interior. However, although the surface contains very little iodine, it has high concentrations of bromine and oxygen. It is believed that the high concentrations of bromine and oxygen in this surface cause the halogenated fiber to be more resistant to structural damage during subsequent fluorination to fabricate graphite fluoride fibers.     

插层技术在纳米复合材料中的应用与进展

介绍了插层技术的机理与插层方法，对插层热力学与动力学进行分析，并对插层技术在纳米复合材料中的应用作一综述。     

聚丙烯/蒙脱土纳米复合材料研究进展

聚合物/蒙脱土纳米复合材料具备特殊的结构和形态。显示出优异的物理化学性能，因此具有重要的科学意义，本文详细介绍聚丙烯/蒙脱土纳米复合材料的制备，制备过程热力学与动力学及其结构和性能，并对其应用前景进行了展望。     

Intercalation Assembly Method and Intercalation Process Control of Layered Intercalated Functional Materials

Layered intercalated functional materials of layered double hydroxide type are an important class of functional materials developed in recent years. Based on long term studies on these materials in the State Key Laboratory of Chemical Resource Engineering in Beiiing University of Chemical Technology, the orinciole for the design of controlled intercalation processes in the light of tuture production processing requirements has been developed. Intercalation assembly methods and technologies have been invented to control the intercalation process for preparing layered intercalated materials with various structures and functions.     

HCIO4型GIC质量变化分析

以HCIO4为主要原料,采用化学氧化法制备HCIO4型GIC,研究了HCIO4-GIC在制备、储存及高温膨胀过程中的质量变化,并对其膨胀体积（VEG）和插层机理做了进一步探讨。结果表明：GIC在制备过程中质量增加,增重率分别为25．3％（30目）、24．3％（50目）、18．5％（80目）;储存过程中GIC质量随时间不断减少,且不同环境的质量损失量（△m）不同,但最后质量趋于稳定,失重率分别为0．668％（25℃密封）、0．842％（25℃暴露）、1．225％（60℃暴露）;由GIC到EG的高温膨胀过程中质量减少,热失重为26．6%,（50目）;相同膨胀温度下FHCIO4-GIC的VEG明显高于H2SO4／HNO3-GIC;插层过程中插层剂以中性分子或阴离子形式插入石墨碳层。     

Effect of intercalated hydrotalcite on swelling and mechanical behavior for poly(acrylic acid‐co‐N‐isopropylacrylamide)/hydrotalcite nanocomposite hydrogels

A series of nanocomposite hydrogels were prepared from acrylic acid (AA), N‐isopropylacrylamide (NIPAAm), and intercalated hydrotalcite (IHT) by photopolymerization. The influence of the intercalating content of 2‐acrylamido‐2‐methyl propane sulfonic acid (AMPS) in HT on the swelling and mechanical properties for poly(AA‐co‐NIPAAm)/IHT nanocomposite hydrogels was investigated. The results showed that the higher the content of the AMPS‐HT was, the higher the swelling ratio of the gels and the higher the content of the intercalating agent was, the lower swelling ratio. It was also demonstrated that the swelling ratio of the gel was not affected by the counterion in HT. The gel strength and crosslinking density were not enhanced by adding AMPS‐HT into the gel composition, but the maximum effective crosslink density and shear modulus of the nanocomposite hydrogels were increased with an increase of the content of the intercalating agent in HT. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1572–1580, 2005