Al13-两性表面活性剂复合插层蒙脱石的合成与结构特征研究

蒙脱石是一种2∶1型层状硅酸盐粘土矿物,具有纳微米级粒径、大比表面积、层间可膨胀性等特点。由于其结构片层中的八面体或四面体中存在类质同象替代,结构层通常带有负电荷,自     

管状埃洛石铝羟基表面的硅烷嫁接及其对布洛芬负载、释放的影响

埃洛石[Al2Si2O5(OH)4.nH2O]是一种1∶1型的层状硅酸盐矿物,其结构单元层由铝氧八面体片和硅氧四面体片组成,结构单元层之间为水分子层。天然埃洛石颗粒多呈管状,其外径通常为30~190 nm,内径10~100 nm,管长0.02~30μm。     

溧阳一带发现一层三斜型叶蜡石

叶蜡石是2:1层状硅酸盐矿物。其基本结构模式为,二个连接成复三方环网状的角顶相对的硅氧四面体片,中间夹一个三水铝石式的铝氧二八面体片,组成一个夹心饼干状的2:1单元结构层,由这种单元结构层重叠堆垛构成叶蜡石晶体。正如同属2:1层状硅酸盐的云母族矿物的多型一样,由于单元结构层迭置重复方式不同,也造成了叶     

高岭石层面羟基的硅烷嫁接改性机理

<正>高岭石[Al2Si2O5(OH)4]是一种1∶1型的层状硅酸盐矿物,其结构单元层由一层[SiO4]四面体片和一层[AlO6]八面体片组成,因此高岭石片层具有两种不同性质的表面:硅氧烷底面和羟基底面。高岭石的羟基底面为硅烷嫁接提供了场所,通过八面体片上的羟基与有机硅烷发生缩合形成Al-O-Si共价键,嫁接后的高岭石材料较之     

云母的命名

定义云母为层状硅酸盐。其结构单元由两个相向排列的四面体片（Ｔｓ）和夹于其间的一个八面体片（Ｏｓ）组成。这些片构成一个单元层,层与层之间被非水化层间阳离子（Ｉ）分开,其顺序是：非水化阳离子层、四面体片、八面体片、四面体片、非水化阳离子层、四面体片、八面...     

高岭石和伊利石的固体酸性受热处理温度的影响及其机理

高岭石([Al4(Si4O10)(OH)8])和伊利石(K0.75(Al1.75R0.252+)[Si3.5Al0.5O10](OH)2)是自然界常见的、具有结构代表性的两种层状硅酸盐矿物。高岭石由硅氧四面体片和铝氧八面体片按1∶1方式组成的结构单元层沿c轴方向排列而成,其片     

甘肃金昌红泉镁基膨润土属型分类

膨润土是一种以蒙脱石为主要成分的粘土类矿物。确定膨润土的属型,实质上是依据蒙脱石晶层间吸附阳离子的种类及其丰度。 (一) 蒙脱石吸附阳离子的主要原因 1.蒙脱石是属于一种2:1层状结构,即由二个硅氧四面体片夹一个铝氧八面体片构成的层状体。蒙脱石因四面体中Al~(3+)置换Si~(4+)和八面体中Mg~(2+)置换Al~(3+),使蒙脱石晶层间产生永久性负电荷,为了保持晶格电荷平衡,因而晶层间具有吸附阳离子和交换性阳离子的性能。     

便携式近红外光谱对层状硅酸盐矿物结构及成因探讨

采用ore XpressTM便携式矿物分析仪获取了高岭石、蛇纹石、滑石、叶腊石、白云母五种层状硅酸盐的近红外光谱谱图,运用矿物学和近红外光谱原理研究发现:二八面体型层状硅酸盐由于八面体空隙的存在,使谱图上1400nm和1900nm附近处的吸收峰强度要强于三八面体型层状硅酸盐的吸收峰强度,并且二八面体型层状硅酸盐的结构单元层是1:1型,因此氢键效应会加剧这种作用;结构单元层类型相同的层状硅酸盐,因八面体片中的阳离子电负性不同,会使金属一羟基叠加峰峰位发生偏移;过渡离子的存在,会使吸收峰的峰强和峰形产生异常;利用不同矿物晶格中分子、离子吸收不同能量的光子后,会在图谱上表现出不同的吸收特征,可反映出样品的矿物类型、结晶度、含水量等信息。     

锌叶绿泥石矿物学研究

绿泥石类矿物是含水的镁、铁、铝层状硅酸盐,矿物结构由似云母层和似水镁石层交替沿C轴堆砌组成。按八面体空穴填充情况分为三八面体和二八面体两类,根据八面体中的阳离子种类不同可形成多种绿泥石矿物,由于四面体中硅被铝置换程度差异又可分为若干亚种。 1973年我们研究鄂北杨家堡下寒武统黑色页岩中的钒矿床时,发现一种绿色粘土矿物,当时定为镍锌绿泥石,后来发现其结构不同于普通绿泥石。进一步研究做了一些工作,今将结果综合     

四川会理白草碱性伟晶岩中含铌的锰星叶石

星叶石是层状钛硅酸盐矿物。M.弗莱谢尔(Fleischer)认为,本族矿物中除锰星叶石(Kupletskite)外,还包括有四个独立变种矿物,它们是星叶石(Astrophyllite)、铌星叶石(Niobophyllite)、锆星叶石(Zircophyllite)和铯星叶石(Cesium-Kupletskite)。根据前人研究,在层状钛硅酸盐中,Ti起着双重作用。一方面可以加入八面体层起着典型的阳离子作用,配位数为Ⅵ;另一方面在所有层状钛硅酸盐结构中都有钛氧八面体和硅氧四面体组成     

尼日利亚石—塔菲石—黑铝镁铁矿及相关系列矿物的晶体结构构筑原理

从氧原子最紧密堆积以及阳离子充填四面体和八面体空隙原理出发 ,以简单氧化物矿物最紧密堆积结构类型金绿宝石、尖晶石、铁钒矿为基础 ,深入讨论了复杂氧化物矿物最紧密堆积结构类型彭志忠石、尼日利亚石、塔菲石、黑铝镁铁 (钛 )矿等晶体结构构筑原理。以O表示全部为阳离子八面体配位的层 ;以T层表示阳离子八面体配位与阳离子四面体配位的混合层 ,其中T1表示阳离子八面体配位与一种方向阳离子四面体配位的混合层 ,T2 表示阳离子八面体配位与两种方向阳离子四面体配位的混合层。这类矿物晶体结构可用O、T1、T2 堆积方式表征 ,O层与T层交替排列。如 :彭志忠石 ( 6H)的晶体结构表示为…OT2 OT1OT1… ,塔菲石 ( 8H)的晶体结构表示为…OT2 OT1OT2 OT1… ,尼日利亚石 ( 2 4R)的晶体结构表示为…OT1OT2 OT2 OT1…× 3 ,等等 ;它们的晶体结构中既有尖晶石的…OT2 OT2 …晶体结构单位 ,又有铁钒矿的…OT1OT1…晶体结构单位。     

柱撑粘土矿物材料的晶体结构和晶体化学特征

以铝基柱撑粘土矿物和钛基柱撑粘土矿物为例，讨论了柱撑粘土矿物材料的晶体结构和晶体化学特点，Al多核笼状阳离子基团的结构形式为1：12Keggin型离子，Ti多核笼状阳离子基团的结构形式为2：19Dawson型离子，两类笼状阳离子的直径均在1nm左右，前者的高度约为0．9nm，后者的高度约为1．4nm，经与粘土矿物层间阳离子交换后，择位固定在粘土矿物层间，由于多核笼状阳离子与粘土矿物硅氧四面体之间形成了较强的化学键，其具有不可交换性，铝基柱撑粘土和钛基柱撑粘土的层间孔道分别为1．2nm*1.2nm*1.2nm，和0.52nm*0.52nm*1.60nm。柱粘土矿物材料有很好的化学稳定性和耐热性，且又有一定的层间化学活性，可用于催化剂载体，由于它又具有选择性吸附能力，有望制造成新一代环保材料。     

Crystal Chemistry Research of Minerals of Nigerite Group and Its Significance

SinceJacobsonandWebb (194 7)firstlyfoundthenigeriteinNigeria ,mineralogistshavefounditinmanycountriessuchasRussia (EastSiberia ,195 8) ,China(Hunan ,196 3) ,Portugal (196 5 ) ,Australia (1976 )andsoon .Greyetal.(1979)determinedaccuratelythecrystalstructureofnigerite (2 4R) .In 1988,Chenfoundakindofendmembermineralofnigerite ,whichisMg riched .ByapprovingofCommissiononNewMineralsandMineralNames (CNMMN) ,thismineralwasnamedpengzhizhongite .Inthepast ,somemineralogistsdidnotfurtherdis t…     

金云母—蛭石间层矿物分晶层晶体化学式的计算及意义

金云母－蛭石间层矿物由金云母晶层与蛭石晶层交叠排列而成，采用一般计算方法得出的晶体化学式不能充分揭示结构中金云母晶层与蛭石晶层各自的晶体化学特征。本文以化学成分分析与阳离子容量为基础，假定可交换性阳离子均为蛭石晶层层间阳离子，非交换性阳离子为金云母晶层层间阳离子，金云母晶层与蛭石晶层具有相同的八面体层等，计算出了结构中两种晶层的分晶层晶体化学式，确定了结构中两种晶层的比例和蛭石晶层的电荷数。并在此基础上讨论了新疆尉犁蛭石矿金云母－蛭石间层矿物的晶体化学特征。结果表明该方法设计合理，符合晶体化学原理，所计算的数据可靠。利用该方法计算出的两种晶层的比例为金云母－蛭石1：1规则间层矿物的确定提供了必要的依据。也为其它类似间层矿物的研究提供了一种计算分晶层晶体化学式的可行方法。     

间层矿物的结构参数与分类探讨

从间层的概念出发，对四个间层结构参数的定义和意义进行总结，并根据间层矿物的结构和组成对其进行了分类探讨。首先根据晶层种类将间层矿物分为同类结构基元间层矿物和异类结构基元间层矿物两大类，然后根据变差系数划分出规则间层矿物和不规则间层矿物，最后根据间层比、连接概率等特征划分出有序间层、无序间层和带状间层。     

墨铜矿的穆斯堡尔谱特征

墨铜矿是典型的异类矿物结构基元层间层矿物．在其结构中，Ｆｅ可占据硫化物层中四次配位和氢氧化物层中六次配位两种位置。本文通过穆斯堡尔谱研究，确定了墨铜矿的穆斯堡尔谱谱型，并认为高自旋的Ｆｅ２＋占据四次配位位置，与Ｃｕ离子一起可能呈无序占位，配位环境的对称性较低，谱参数为：ＩＳ＝０．４２－０．４８ｍｍ／ｓ、ＱＳ＝０．８１－１．２８ｍｍ／ｓ及Ｈｉ约为２４０ＫＯｅ；低自旋的Ｆｅ３＋占据六配位位置，ＩＳ值为０．３２－０．３６ｍｍ／ｓ、ＱＳ值为０．４４－０．５９ｍｍ／ｓ。     

DFT study of the cation arrangements in the octahedral and tetrahedral sheets of dioctahedral 2:1 phyllosilicates

Quantum mechanical calculations based on the density functional theory (DFT) are used to study the crystal structures of dioctahedral 2:1 phyllosilicates. The isomorphous cation substitution is investigated by exploring different substitutions of octahedral Al³⁺ by Mg²⁺ or Fe³⁺, tetrahedral substitution of Si⁴⁺ by Al³⁺, and different interlayer cations (IC) (Na⁺, K⁺, Ca²⁺, and Mg²⁺). Samples with different kinds of layer charges are studied: only tetrahedrally charged, only octahedrally charged, or mixed octahedral/tetrahedral charged. The effect of the relative arrangements of these substitutions on the lattice parameters and total energy is studied. The experimental observation of segregation tendency of Fe³⁺ and dispersion tendency of Mg²⁺ in the octahedral sheet is reproduced and explained with reference to the relative energies of the octahedral cation arrangements. These energies are higher than those due to the IC/tetrahedral and IC/octahedral relative arrangements. The tetrahedral and octahedral substitutions that generate charged layers also tend to be dispersed. The octahedral cation exchange potentials change with the IC-charge/ionic radius value.     

The A and B mica layers and the crystal structure of sheet silicates

A discussion of the transition from the ideal hexagonal mica structure to the ideal ditrigonal one, leads to the conclusion that the single mica layer may have two different structures (labelled A and B). The recent literature data show that both the A and B structures have been detected in some triocahedral layer lattice silicates found in nature. An examination of the structural stability of the A and B structures suggests that the last one may not be realized by dioctahedral layer lattice silicates. The concept of two structurally different mica layers, which however have the same lattice constants, greatly improves the understanding of polymorphism and twin laws in layer lattice silicates.The structural features of the tetrahedral sheet, octahedral sheet and interlayer region are carefully examined. Thus we can reach the following conclusions: the tetrahedal sheet is not entirely free to reduce its lateral dimensions by the mechanism of tetrahedal rotation owing to the repulsion among O_bas atoms; the octahedral sheet in layer lattice silicates, may increase or reduce its lateral dimensions as compared to the lateral dimensions it has in the hydroxide minerals; the interlayer region is characterized by a regular octahedral coordination of the O_bas around the interlayer cation. On the ground of these conclusions, new structural models for some selected layer lattice silicates are proposed.Notations O_bas basal oxygen atoms of the (Al, Si)O₄ tetrahedra - O_ap apical oxygen atoms of the (Al, Si)O₄ tetrahedra - b _tetr b dimension which the tetrahedral sheet would assume if unconstrained - b _oct b dimension which the octahedral sheet has in the hydroxide minerals - b _obs observed value of b - c _oct ^* thickness of the octahedral sheet - d _o distance between an octahedral cation and an O_ap atom - d _int distance between an interlayer cation and an O_bas atom - average tetrahedral rotation from ideal hexagonal symmetry     

Microstructures and compositional variation in the intravolcanic bole clays from the eastern Deccan volcanic province: Palaeoenvironmental implications and duration of volcanism

Clay minerals associated with intra-volcanic bole horizons of varied colours and thicknesses contain montmorillonite, halloysite and kaolinite, show distinct microstructures and microaggregates. In kaolinite, Fe³⁺ ions substitute for Al³⁺ at octahedral sites. Most of these clays are dioctahedral type, show balance between net layer and interlayer charges. The interstratified illite — smectite (I/S) mixed layers containing variable proportions of montmorillonite. Illite contains sheet-like, well oriented microaggregates. The parallel stacks of chlorite sheets show chlorite/smectite (C/S) mixed layers. Progressive enrichment of Fe and depletion of Al ions with the advancement of kaolinization process is observed. High order of structural and compositional maturity observed in these bole clays, indicate long hiatus between the two volcanic episodes.     

Polysomatism,polytypism, defect microstructures,and reaction mechanisms in regularly and randomly interstratified serpentine and chlorite

High-resolution (HRTEM) and analytical electron (AEM) microscopic evidence for a polysomatic series based on regular interstratifications of serpentine (amesite) and chlorite (clinochlore) are reported from an altered skarn in Irian Jaya. The assemblage includes regular interstratifications of one clinochlore and two (2:1; three structural variants), three (3:1), and four (4:1) amesite composition 1:1 layers as well as randomly interstratified serpentine and chlorite. The order of abundance of regularly interstratified minerals is 1:1>2:1>4:1>3:1. Atomic-resolution images, image simulations, and comparison between calculated and observed diffracted intensities verify the proposed 1:1 and 2:1 structures and reveal details of their defect microstructures. AEM data show that compositions are linear combinations of the associated amesite and clinochlore. The 1:1, 2:1, 3:1, and 4:1 minerals occur both as discrete sub-micron crystals and as domains within serpentine or chlorite. Some crystals of the 2:1 phase were sufficiently large for study by X-ray precession and powder methods. Crystals of the regularly interstratified 2:1, 3:1, and 4:1 phases are usually bent. High-resolution images reveal that, within polygonal segments, the layers commonly exhibit a few degrees of curvature with segments separated by antigorite-type offsets. Deformed chlorite crystals are probably replaced by interstratified minerals during an aluminum metasomatic event. Al may have been deposited from sulfuric acid-rich solutions when they interacted with calcite and dolomite to form the anhydrite-rich corona around the phyllosilicate-rich region of the core. The interstratified chlorite (clinochlore composition) suggests aluminum addition by selective conversion of a sub-set of the chlorite layers to amesite. Defect microstructures suggest that crystals of regularly interstratified material grew by direct structural modification of preexisting chlorite. Regular interstratifications may form in response to thermally controlled limits on Al solubility in chlorite and heterogeneities in the distribution of Al-rich solutions during metasomatism. Regularly interstratified minerals coexist with randomly interstratified serpentine/chlorite, chrysotile, antigorite, lizardite, and several amesite and chlorite polytypes. Tentative chlorite and amesite identifications include one-layer (b=97°, probably IIbb), one-layer (b=90, possibly Ibb), two-, and three-layer chlorites, and 2H₁ (but possibly 1M or 1T), rhombohedral (3R or 6R), and twelve-layer (Tc; non standard) serpentine polytypes. The complex phyllosilicates attest to rampant chemical and structural disequilibrium.