共查询到20条相似文献，搜索用时 218 毫秒
1.
《吉林大学学报(地球科学版)》2015,(Z1)
<正>层状双氢氧化物(layered double hydroxides,LDHs)作为一种阴离子型层状材料,由于其层板元素组成及层间阴离子的可调变性,在医药、生物、新能源、催化、环境等领域表现出良好的应用前景。在适宜的条件下,LDHs颗粒能够被剥离成分散状态的纳米片。剥离后的纳米片层带正电,且拥有二维尺度,因此被用作基础研究的模型,并通过自组装来构建新型纳米复合材料。剥离后的LDHs片层带有正电荷,具 相似文献
2.
矿物材料在纳米科技中的应用 总被引：6，自引：1，他引：6
纳米材料由于其独特的性能和广阔的应用前景被称为21世纪的新材料、其制备技术是纳米科技的核心和研究基础。具层状结构和微孔空间的矿物材料可用于制备纳米微粒，为纳米科技提供了新的思路和生长点，也为矿物材料在高新技术领域的应用开辟新的途径。本文综述了蒙脱石、高岭石和文石珍珠层在纳米科技中的应用，粘土／有机物纳米复合材料、无机介孔材料和仿生纳米材料的制备和应用前景。 相似文献
3.
高岭石性质的尺寸效应 总被引：1，自引：0，他引：1
高岭石性质的尺寸效应陈国玺翁克难肖万生（中国科学院广州地球化学研究所，广州５１０６４０）关键词高岭石粒度纳米尺寸性质高岭石的层间距为０．７３ｎｍ。天然高岭石中虽然单颗粒片状晶体的粒径为２μｍ左右，但大部分组成叠片状集合体，几组叠片又可集合在一起组成更... 相似文献
4.
高岭石-聚丙烯酰胺插层原位合成Sialon粉体 总被引：5，自引：1，他引：4
以高岭石聚丙烯酰胺插层复合物为前驱体,采用原位碳热还原、氮化反应技术,在1400（合成了Sialon粉体。并运用XRD,FT-IR,TEM等技术对合成产物的组成、结构及形貌特征进行研究发现：以插层复合物为前驱体的合成反应,β＇-Sialon,O’-Sialon为主晶相,不舍方石英;而以高岭石-碳混合物为原料的合成产物中,相组成复杂,β＇-Sialon含量较低,并有氧化物。高岭石插层复合物原位碳热还原、氮化反应是合成β＇-Sialon的一种新颖而有效的方法．插层复合物有序的纳米级层状结构特征是提高碳热还原、氮化反应效率的主要原因。 相似文献
5.
运用X射线衍射、红外光谱及固体高分辨核磁共振等手段，研究了苏州高岭石560～1600℃热变产物，结果显示：①高岭石．偏高岭石．莫来石的转变系列存在结构上的连续性，其转变经历了脱羟阶段（约400～600℃），偏高岭石阶段（600～800℃），相分离阶段（800～1100℃），莫来石阶段（1100～1600℃）；②莫来石形成过程没有出现AlO3的大量分凝，但存在SiO2分凝；③偏高岭石．莫来石转变过程的中间相为Al-Si尖晶石和准莫来石；④引起1000℃放热反应的主要因素是SiO2的大量分凝，其次是准莫来石等过渡相的形成。 相似文献
6.
通过对醋酸钾/高岭石插层复合物的机械磨剥制备了不同径厚比的高岭石样品,并利用X射线粉晶衍射(XRD)、激光粒度仪、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和傅里叶变换红外光谱(FTIR)表征了4个样品的粒径、结构以及形貌。实验结果表明:随着插层磨剥次数的增加,高岭石的结晶度指数(HI)由原矿的1.29降至0.69,结晶度降低,晶体结构在一定程度上遭到破坏。同时,4个样品的粒径及厚度逐渐减少,径厚比依次增大至11.7。此外,经过3次插层磨剥洗涤后,部分剥离的片层发生卷曲,但很少完全卷曲成纳米卷。 相似文献
7.
煤系高岭石—醋酸钾复合体的热行为 总被引：7，自引：0，他引：7
用煤系高岭石与醋酸钾合成夹层复合体，并利用热分析（TA）、红外光谱（IR）和X射线衍射（XRD）等手段研究其热行为特征。夹层复合体在低于300℃左右的条件下相当稳定，当温度进一步升高，夹在高岭石层间的醋酸钾就会发生熔化，在此阶段脱羟基作用发生。复合体脱羟基所需的温度比纯高岭石发生同样作用所需的温度要低得多。红外光谱研究发现，高岭石复合体中不同性质羟基团的脱羟基作用的发生遵循着一个固定的顺序。 相似文献
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高岭石矿物学研究现状及其发展方向朱如凯（北京大学地质学系，１００８７１）高岭矿物包括高岭石、迪开石、珍珠陶石，为典型的１：１型二八面体矿物。自从本世纪４０年代第一个高岭石结构建立以来（Ｂｒｉｎｄｌｅｙ，１９４６），相继围绕高岭石矿物的工业应用开展了一... 相似文献
11.
Pi Zhenbang Liu Zhuoqin Yang Chao Tian Xike Fei Jinbo Zheng Jianhua 《Frontiers of Earth Science》2007,1(1):26-29
A type of exfoliated kaolinite was produced by urea-intercalation and original microwave irradiation assisted method. The
product was investigated by Fourier transformation infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning electronic
microscopy (SEM), Brunauer-Emmett-Teller (BET) and laser particle analysis techniques. FT-IR spectra show that NHCO molecule
exists in the intercalated kaolinite. XRD analyses indicate that the kaolinite sheet-like structure was disordered after microwave
irradiation. The urea decomposition process and explosion effect between the sheet-like structures of kaolinite under microwave
irradiation were discussed. The SEM and BET analyses reveal that the end product is exfoliated kaolinite with thin particles
and increased surface area. Size and zeta potential analyses show that the particle size distribution is between 250 nm and
550 nm with normal distribution and the particle is negatively charged. In comparison with the conventional grind method,
the process adopted appears to be economic and the exfoliated kaolinite end product may display a significantly enhanced performance
in industrial applications. 相似文献
12.
Four outcrops of Lower Cretaceous (Barremian) karst bauxites located in Teruel (NE Spain) were analysed to determine their mineral associations and genesis related to climatic palaeoweathering events and late superimposed kaolinization processes. The materials comprise metric‐sized pisolitic blocks embedded in a clay‐rich red groundmass. Fourteen samples were examined by X‐ray diffraction, optical microscopy, scanning and transmission electron microscopy and the major elements were analysed by inductively‐coupled plasma mass spectroscopy (ICPMS). The samples are composed of kaolinite, gibbsite, goethite, and hematite as the main phases, with diaspore, boehmite, anatase, and rutile as accessory minerals. The results show a complex sequence of mineralogical and geochemical processes that transformed the parent rock into the current bauxite materials. The clay‐rich groundmass constitutes the lateritic parent material of the pisolitic bauxites. In the parent material authigenic kaolinite (e.g. vermicular kaolinite and kaolinite between cleavage sheets of pre‐existing mica) has been observed; Fe oxides formed subsequent to kaolinite. In the pisolitic bauxites, mineralogical and textural evidence indicates that bauxitization took place at the expense of previous kaolinite, with gibbsite post‐dating the other Al hydroxides. The pisolitic bauxites also show a more homogeneous chemical composition and a relative Ti, Al and Zr enrichment. The data are consistent with an intense palaeoweathering event during the Lower Cretaceous (Barremian) under tropical climatic conditions (warm and humid). Several stages probably took place during the bauxitization process, suggesting variations in water saturation conditions. Subsequent karst reactivation stages and related collapses were responsible for the present lithostructure of the deposits and allowed late kaolinization not related to climate to take place. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
13.
本文将微波技术引入到制备高岭石/有机物插层复合物的研究中,以DMSO为前驱体,研究了微波辐射对高岭石的有机插层、取代、原位聚合作用.发现微波能加快插层和置换反应,极大地缩短反应时间.微波辐射下插层时间为30 min时,插层率即可达到75%以上,置换反应50 min,置换率达到77%以上.同时发现微波在反应中对高岭石具有剥片效果.采用X射线衍射、FT-IR光谱、TG、TEM等技术对插层复合物及微波作用机理进行了探讨. 相似文献
14.
C. Fourdrin E. Balan T. Allard C. Boukari G. Calas 《Physics and Chemistry of Minerals》2009,36(5):291-299
Radiation effects on kaolinite were investigated using He+ ions of 1.5 MeV at radiation doses up to 4.3 × 108 Gy, which are comparable to the doses expected for clay barriers in high-level nuclear waste repositories. The concentration
of paramagnetic radiation-induced defects in kaolinite reaches 2 × 1016 spins/mg (400 at. ppm), as determined by electron paramagnetic resonance spectroscopy. The broadening of X-ray diffraction
patterns and transmission infrared (IR) absorption bands is mostly related to the structural strain induced by radiation-induced
point defects. The broadening of IR absorption spectra is analyzed using an autocorrelation approach and is related to a change
in the distribution of vibrational frequencies due to crystal heterogeneities. We theoretically analyze how the effective
dielectric properties of kaolinite samples depend on macroscopic parameters and how irradiation can modify some of them. Irradiation
leads to an increase in the electronic polarizability of kaolinite particles, related to the accumulation of radiation-induced
electronic point defects. 相似文献
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Ahmed Al-Futaisi Ahmad Jamrah Amer Al-Rawas Saif Al-Hanai 《Environmental Geology》2007,51(8):1317-1327
In this paper, Shuwaymiyah palygorskite in the Sultanate of Oman has been characterized mineralogically by X-ray diffraction
(XRD) and electron microscopy, chemically by oxide compositions, structural formulae, and cation exchange capacity (CEC),
and physically by specific surface area and adsorption isotherms. Batch adsorption studies were performed to evaluate the
adsorption performance of methylene blue (MB) basic dye on the local clay mineral. The quantitative XRD analysis indicates
that the purity of some selected samples of palygorskite clay is very high (about 70% of the clay minerals are palygorskite
and 30% kaolinite). The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images clearly support
this conclusion. The adsorption equilibrium revealed that Shuwaymiyah palygorskite clay can uptake up to 51 mg of MB per 1 g
mass of clay. MB adsorption is best fitted by Langmuir isotherm, and a pseudo-second-order kinetic model can be efficiently
used to predict the kinetic of adsorption of MB by the palygorskite. The results obtained from these laboratory-scale adsorption
tests indicate the promising adsorption capability of the Omani palygorskite. 相似文献
17.
粘土矿物碱耗协同效应研究 总被引：4，自引：0，他引：4
选择蒙脱石,高岭石,伊利石等三种在储层中最党风的储层粘土矿物,两两分别按２Ｌ：０,１：１,０：２质量配比组成复配物系列;在３０℃、５０℃温度下按１：５,１：８,１：１０（ｇ／ｍｌ）固／液比分别与１．６％的Ｎａ２ＣＯ３深液反应８ｈ,３６０ｈ;监测反应前后碱液浓度的变化;计算了各条件下各自的绝对碱耗量。结果表明三种粘土矿物中蒙脱石耗碱最大,高蛉石的耗碱量与伊利石的接近;随着固／液比减小和温度升高,矿物 相似文献
18.
由于重金属镉离子的吸附性能较差、毒性大,因此,寻找镉离子的高效吸附材料具有重要现实意义。本文开展巯基硅烷对高岭石的嫁接改性研究,经红外光谱测试证实,成功将巯基引入到高岭石表面。同时,硅烷改性对高岭石晶体结构没有产生影响。通过批量实验考察了高岭石和巯基硅烷改性高岭石(K-SH)对Cd(Ⅱ)的吸附特征,主要探讨了p H值、时间对吸附效率的影响。矿物对Cd2+的吸附动力学符合准二级动力学模型,吸附等温方程更符合Langmuir模型,并估算的K-SH的最大吸附量是4.375 mg/g,比高岭石的大近20倍。改性高岭石表面嫁接了巯基后,可为高岭石吸附Cd(Ⅱ)提供大量的新吸附位点,通过配位复合作用显著提高对镉离子的吸附固定能力。因此,巯基硅烷改性高岭石是一种有应用前景的土壤修复材料。 相似文献
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对江西赣南6个地区风化淋滤型稀土矿中全风化层的粘土矿物进行了研究,为进一步了解粘土矿物对该类型稀土矿中稀土元素分异的影响奠定了基础。X射线衍射自然定向片、甲酰胺片、饱和乙二醇片和加热片、红外光谱及扫描电镜观察结果表明该区粘土矿物以片状高岭石和针管状7埃洛石为主,其中坳背塘、长坑屋、上堡、杨村样品主体为高岭石,足洞样品中发育大量埃洛石,而石排样品中高岭石与埃洛石比例相当。电感耦合等离子体质谱分析表明稀土元素在粘土矿物中大量富集,其稀土元素配分不仅受到原岩的影响,而且受到粘土矿物本身性质的影响。Ce元素在足洞和石排样品的粘土矿物中表现出正异常,而在其他样品粘土矿物中表现为负异常,可能与其中发育的埃洛石密切相关。Ce元素可能以方铈矿胶膜的形式包裹在针状埃洛石中,和/或以离子形式被选择性吸附于埃洛石表面。 相似文献
20.
Qi Fu Peng Lu Hiromi Konishi Robert Dilmore Huifang Xu W.E. Seyfried Chen Zhu 《Chemical Geology》2009,258(3-4):125-135
Batch reactor experiments were conducted to assess perthitic alkali-feldspar dissolution and secondary mineral formation in an initially acidic fluid (pH = 3.1) at 200 °C and 300 bars. Temporal evolution of fluid chemistry was monitored by major element analysis of in situ fluid samples. Solid reaction products were retrieved from two identical experiments terminated after 5 and 78 days. Scanning electron microscopy revealed dissolution features and significant secondary mineral coverage on feldspar surfaces. Boehmite and kaolinite were identified as secondary minerals by X-ray diffraction and transmission electron microscopy. X-ray photoelectron spectroscopy analysis of alkali-feldspar surfaces before and after reaction showed a trend of increasing Al/Si ratios and decreasing K/Al ratios with reaction progress, consistent with the formation of boehmite and kaolinite.Saturation indices of feldspars and secondary minerals suggest that albite dissolution occurred throughout the experiments, while K-feldspar exceeded saturation after 216 h of reaction. Reactions proceeded slowly and full equilibrium was not achieved, the relatively high temperature of the experiments notwithstanding. Thus, time series observations indicate continuous supersaturation with respect to boehmite and kaolinite, although the extent of this decreased with reaction progress as the driving force for albite dissolution decreased. The first experimental evidence of metastable co-existence of boehmite, kaolinite and alkali feldspar in the feldspar hydrolysis system is consistent with theoretical models of mineral dissolution/precipitation kinetics where the ratio of the secondary mineral precipitation rate constant to the rate constant of feldspar dissolution is well below unity. This has important implications for modeling the time-dependent evolution of feldspar dissolution and secondary mineral formation in natural systems. 相似文献