共查询到20条相似文献，搜索用时 187 毫秒
1.
以溴化十六烷基三甲铵为改性剂，对天然钙基膨润土进行有机化改性，系统地研究了改性剂用量以及钠化，热活化和酸活化对有机膨润土吸附苯酚、苯胺、苯、甲苯和二甲苯的影响，并初步探讨了有机膨润土与有机物间的作用机理。实验结果表明，改进剂用量是影响有机膨润土对有机物吸附性能的主要因素；改性剂用量相同时，钠化土的吸附效果明显好于直接改性的6.0%土，而热活化和酸活化对于有机膨润土吸附不同的有机物时影响程度也不同。应用有机膨润土建造垃圾填埋场防渗衬层具有一定的可行性。 相似文献
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通过对天然钙基膨润土钠化改性过程以及有机改性过程中混炼挤压的实验,分析了混炼挤压对膨润土分散的影响。实验结果表明,混炼挤压作用可以有效地提高钙基膨润土的钠化度以及膨润土颗粒的分散度和ξ电位。 相似文献
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有机膨润土的合成与特性研究 总被引：3，自引：1，他引：3
利用二甲基羟乙基十八烷基季铵盐[(CH)2(HOC2H4)(C15H37)NCl]与钠基蒙脱石进行离子交换反应，合成了有机膨胀土，采用化学，X－射线射，差热，红外吸收光谱和凝胶试验应运地其物化性能进行了研究，膨润土的d001由原来的1.250nm变至4.016nm，它在硝基苯，二甲苯－甲醇，紫油－水中具有良好的分散性和流变性，廉政明湖北某矿的膨润土制备有机土有较好的开发利用价值，本文提出了有机覆盖剂用量的计算公式，并对有机膨润土的覆盖和溶剂化机理进行了探讨，指在有机蒙脱石中，有机阳离子按定向排列或吸附于上下层面上，均为双层吸附，有机蒙脱石的层产距是有机阳离子的有效长度L及其层夹角θ的函数，d001＝L.sinθ 0.96，有机土的溶剂化和凝胶化性能主要取决于蒙脱石的有机化程度和溶剂的性质。 相似文献
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以过硫酸钾为引发剂,通过水溶液聚合法制得了丙烯酸和丙烯酰胺的聚合物A。用聚合物A作为有机改性剂,采用混炼挤压法制备得到样品。用X射线衍射(XRD)、红外光谱(FT-IR)、扫描电子显微镜(SEM)等方法对其结构形貌进行研究。结果表明,其晶面间距由原来的1.269 nm增大到1.322 nm,有机基团进入层间,并且仍保持层状结构,成功制备出了有机改性膨润土。用有机改性膨润土配制钻井液,当其质量分数为4%时,浆液的粘度为5.5 mPa.s,滤失量为13 mL,润滑系数为0.13。与普通钠基膨润土钻井液相比,有机改性膨润土钻井液的滤失量和润滑系数均有较大幅度降低,并且改善了钻井液的流变性。 相似文献
6.
叶玲 《矿物岩石地球化学通报》2005,24(2):121-124
为利用膨润土的层间活性有效提高其吸附性能，用各种方法合成金属钛的聚合体，并引入膨润土层间进行改性，研究了合成方法、条件等对膨润土结构、性能的影响，并以红色染料模拟有机废水探讨其吸附性。结果表明，聚合体的合成方法、浓度及介质的pH等条件对改性膨润土的结构和性能均有影响。用Ti在层间水解生成聚合体的合成方法能够有效地改性膨润土、增大层间距、提高其吸附性。 相似文献
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膨润土的热稳定性及其热处理过程中微结构和性能的变化直接影响着膨润土在矿物材料领域的应用,因此研究热处理过程中膨润土成分结构的演化以及表面性质的变化具有重要意义。目前对膨润土的研究多集中在钠化改型、有机化改性以及改型改性后的结构和性能方面,而对膨润土热处理过程中的微观结构和物化性能变化研究有待加强。本文以新疆柯尔碱膨润土为研究对象,在不同温度下进行热处理,利用X射线荧光光谱法分析原土的化学成分,通过同步热分析、X射线衍射、红外光谱以及扫描电镜等技术对热处理产物进行了物相分析和结构表征,并研究了比表面积、吸蓝量及胶质价在升温过程中的变化特征。结果表明:随着热处理温度的升高,柯尔碱膨润土的比表面积逐渐减少,物相组成和结构都发生了很大变化。加热到600℃后,膨润土的吸蓝量和胶质价急剧下降,其主要成分蒙脱石八面体片中的羟基开始脱出,层状结构发生破坏;800℃后蒙脱石相已经消失;1000℃时产生新的矿相——堇青石,粉末颗粒出现熔融现象;1200℃后转变为方石英相,颗粒基本完全熔融,重结晶现象明显。研究认为,600℃时柯尔碱膨润土的膨胀性和分散性基本丧失,矿物物化性能失效。 相似文献
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通过改进滤失试验研究典型钠化改性钙基和天然钠基膨润土在重金属铅-镉以及铬作用下渗透系数的变化规律。研究发现,膨润土试样渗透系数在重金属铅-镉浓度小于6mmol/L时增幅较小,为2~3倍;当浓度超过10mmol/L时呈急剧增大的趋势。铬酸钾溶液作用下,钠化改性钙基膨润土的渗透系数低于未污染试样;天然钠基膨润土的渗透系数则增大2~8倍。两者差异归因于土-液相互作用下铬在不同pH-Eh环境中化学形态的不同。研究中钠化改性钙基膨润土浆液中铬以阴离子络合的六价铬形态存在,使得膨润土颗粒表面负电荷密度趋于增加,因而保持和促进膨润土的分散状态。天然钠基膨润土浆液中铬则出现以阳离子形态存在的三价铬,显著挤压膨润土颗粒双电层,导致膨润土颗粒团聚。综合国内外研究总结无机盐溶液作用下膨润土化学相容性随污染程度变化规律,发现渗透系数比与离子强度关系存在一临界值,当离子强度达到该临界值则渗透系数将呈数量级增大。 相似文献
10.
蒙脱石层电荷与有机改性蒙脱石凝胶性能关系研究 总被引：2，自引：2，他引：2
利用自然沉降法提取了山东两不同产地膨润土中的钙基蒙脱石矿物M1和M2,利用结构式推算法计算了两提纯蒙脱石的层电荷:M1单位半晶胞的层电荷为0.38,M2单位半晶胞的层电荷为0.59;利用十八烷基三甲基氯化铵对蒙脱石进行有机改性,并对有机蒙脱石凝胶性能和层电荷的相关关系进行研究。研究发现:蒙脱石单位半晶胞的层电荷越低,在水中的分散性越好,越有利于十八烷基三甲基铵阳离子的插层,相应有机改性蒙脱石在二甲苯和乙醇体系中的凝胶性能越好(如M1);蒙脱石单位半晶胞的层电荷越高,在水中的分散性越差,越不利于十八烷基三甲基铵阳离子的插层,相应有机改性蒙脱石产品的凝胶性能较差(如M2)。 相似文献
11.
《矿物学报》2013,(Z1)
Montmorillonites (MMT) was modified with nonionic surfactant Trion X-100 (OP-10) and anionic surfactants sodium stearate (SSTA) and sodium dodecyl benzene sulfonate (SDBS) respectively. In this study, the effects of anionic surfactant types and MMT types on modification montmorillonite were investigated. XRD analysis results showed that SSTA/OP-10/MMT and SDBS/OP-10/MMT were successfully obtained. The basal spacing of SSTA/OP-10/MMT reached 5.07nm and the SSTA intercalation reaction was relatively stable. Different types of MMT (Xinjiang natural sodium montmorillonite(MMT-1), Jianping sodium montmorillonite (MMT-2) and artificial sodium montmorillonite(MMT-3)) were modified with SSTA/OP-10. XRD test results showed that MMT-1, MMT-2 and MMT-3 can be modified by SSTA/OP-10. Anion-nonionic organic montmorillonite (SSTA/OP-10/MMT-1, SSTA/OP-10/MMT-2 and SSTA/OP-10/MMT-3 were successfully obtained respectively. The higher expansion capacity was found to be beneficial to organic modification. 相似文献
12.
Ximena Diaz William P. Johnson Diego Fernandez David L. Naftz 《Applied Geochemistry》2009,24(9):1653-1665
The characterization of trace elements in terms of their apportionment among dissolved, macromolecular, nano- and micro-particulate phases in the water column of the Great Salt Lake carries implications for the potential entry of toxins into the food web of the lake. Samples from the anoxic deep and oxic shallow brine layers of the lake were fractionated using asymmetric flow field-flow fractionation (AF4). The associated trace elements were measured via online collision cell inductively-coupled plasma mass spectrometry (CC-ICP-MS). Results showed that of the total (dissolved + particulate) trace element mass, the percent associated with particulates varied from negligible (e.g. Sb), to greater than 50% (e.g. Al, Fe, Pb). Elements such as Cu, Zn, Mn, Co, Au, Hg, and U were associated with nanoparticles, as well as being present as dissolved species. Particulate-associated trace elements were predominantly associated with particulates larger than 450 nm in size. Among the smaller nanoparticulates (<450 nm), some trace elements (Ni, Zn, Au and Pb) showed higher percent mass (associated with nanoparticles) in the 0.9–7.5 nm size range relative to the 10–250 nm size range. The apparent nanoparticle size distributions were similar between the two brine layers; whereas, important differences in elemental associations to nanoparticles were discerned between the two layers. Elements such as Zn, Cu, Pb and Mo showed increasing signal intensities from oxic shallow to anoxic deep brine, suggesting the formation of sulfide nanoparticles, although this may also reflect association with dissolved organic matter. Aluminum and Fe showed greatly increased concentration with depth and equivalent size distributions that differed from those of Zn, Cu, Pb and Mo. Other elements (e.g. Mn, Ni, and Co) showed no significant change in signal intensity with depth. Arsenic was associated with <2 nm nanoparticles, and showed no increase in concentration with depth, possibly indicating dissolved arsenite. Mercury was associated with <2 nm nanoparticles, and showed greatly increased concentration with depth, possibly indicating association with dissolved organic matter. 相似文献
13.
采用生烃动力学方法对鄂尔多斯已熟烃源岩进行模拟实验,与以往结果有所不同,实验证明在源岩二次生烃过程中,慢速升温并不利于液态烃的生成,而快速升温才更有利于生成液态烃。这可能是因为在慢速升温条件下,有机质可以有足够长时间缩聚成超大基团,而快速升温则易造成中等分子链的断裂,从而导致快速升温时抽提物产率高于慢速升温。因此,升温速率的差异对有机质的演化影响不只是影响反应速率,更重要的是会改变反应路径,从而对于像鄂尔多斯这样存在二次生烃的盆地,应适当重视那些高地温梯度区块石油资源的寻找。 相似文献
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采用十六烷基三甲基溴化铵(HDTMAB)对蛭石精矿进行了有机改性,利用X射线衍射法(XRD)、红外光谱(IR)、差示扫描量热法(DSC)和热失重分析(TG)对蛭石精矿和有机改性蛭石进行了表征。实验结果表明,当反应液中蛭石与水的质量比为1∶10、反应温度在60~70℃时,HDTMAB的阳离子HDTMA进入绝大部分蛭石晶粒的晶层,将蛭石的晶层间距撑大,蛭石的(001)晶面间距d001从1.45986 nm增大到3.70134 nm。HDTMA进入了单晶颗粒之间,将蛭石颗粒分散成单晶颗粒。 相似文献
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Examination with scanning electron microscopy (SEM) and scanning force microscopy (SFM) revealed etch pits, layers and islands on dolomite crystal faces synthesized from calcite in Ca‐Mg‐Cl solutions at 200 °C and a wide variety of natural dolomites. Layers are broad, flat structures bounded by steps less than 100 nm high and greater than 1 μm wide. Islands are rounded topographic highs <20 nm high and <200 nm wide. The nanotopography of synthetic dolomite changed from islands throughout most of the reaction to layers at 100% dolomite. Island nanotopography formed on both Ca‐rich and near‐stoichiometric dolomite. Analyses of reaction products from dolomite synthesis indicates that there are no SFM‐detectable products formed in <10 h. SEM‐detectable products formed in 15 h. X‐ray diffraction (XRD)‐detectable products formed in ≈18 h, and the reaction went to completion in ≈40 h. Based on SFM analyses, the induction period for dolomitization in these experiments accounts for ≈20% of the total reaction time necessary to dolomitize CaCO3 completely under the experimental conditions used here. Island nano‐ topography is inferred to occur at higher degrees of supersaturation than layer nanotopography for three reasons. First, island nanotopography on synthetic calcite and gypsum forms at higher supersaturations than layer nanotopography. Secondly, island nanotopography formed in solutions with higher degrees of supersaturation with respect to dolomite. Thirdly, the greater surface roughness of a crystal face composed of islands compared with layers indicates that island surfaces have higher surface energy than layer surfaces. Therefore, the stability of island surfaces requires a higher degree of supersaturation. Because islands and layers form under a wide range of conditions, their presence provides broadly applicable criteria for evaluating relative degrees of supersaturation under which ancient dolomite formed. Comparison of synthetic dolomites with natural dolomites demonstrates (1) similar nanotopography on natural and synthetic dolomites and (2) both natural planar and non‐planar dolomite may have island nanotopography. 相似文献
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Chlorite and associated minerals from the volcanogenic Taveyanne metasediment of the western Helvetic nappes, Switzerland, were investigated by electron microprobe (EMP) and transmission electron microscopy (TEM) in order to determine their textural and chemical evolution during low-temperature metamorphism. EMP analyses of chloritic material from sub-greenschist facies outcrops show a decrease of Si and Σ(Ca, Na, K) with increasing metamorphic grade. A number of conclusions may be drawn from combined TEM images and analytical electron microscopy (AEM) data. 1 In diagenetic-grade samples, chlorite crystals (observed maximum defect-free distance=80 nm) always contain some 1 nm layers (with a maximum of 29% of all layers) and less frequently some 0.7 nm berthierine-like layers. With increasing grade, the amounts of 1 and 0.7 nm layers decrease, and most chlorite from the epizone is structurally pure or contains less than 2% of 1 nm layers. 2 A positive correlation was found between the amount of 1 nm layers and the Ca+K+Na content, indicating that the 1 nm layers are saponite. 3 Observations and calculations suggest that the transformation reaction of saponite to chlorite takes place by the replacement of the interlayer cations in saponite by brucite-like layers resulting in a local volume decrease. In contrast, the destruction of berthierine has only minor influence on the local bulk volume. These results confirm recent studies which show that the change in composition measured by EMP of diagenetic-grade chloritic material are mainly the result of mixtures of chlorite and saponite. The use of chlorite ‘geothermometry’ in such systems is greatly influenced by the presence of saponite and hence is not based on reaction equilibria, even though temperatures calculated in this study agree with temperatures derived from other methods. Therefore, chlorite evolution should be treated as a kinetically controlled grade indicator and developed as a qualitative scale similar to the illite crystallinity index. 相似文献
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针对四川盆地五峰组—龙马溪组过成熟海相页岩,开展普通薄片观察、SEM成像、X-衍射全岩组分和黏土矿物分析、TOC含量测定、N2-CO2联合吸附实验和RG测定。结果表明,海相页岩发育有机孔、无机孔和微裂缝。有机孔多呈气孔状或海绵孔状,大、小混杂;无机孔多呈三角状、棱角状或长方形状;微裂缝多呈条带状,能有效沟通有机孔和无机孔。过成熟海相中,有机孔数量个数>97%,无机孔和微裂缝数量<3%。孔隙以孔径<10 nm的微孔和介孔为主,孔隙数量和体积占比均大于80%,孔径>10 nm的孔隙数量和体积不足20%。在大于10 nm的介孔和宏孔中,有机孔数量超过97%,面孔率超过50%,无机孔和微裂缝数量不足3%,面孔率低于50%。介孔孔径以5~400 nm为主,孔径<20 nm的数量占比>70%。有机孔面孔率随着孔径增大而增大,孔径为100~400 nm的孔隙面孔率占比普遍超过50%。无机孔主要为石英晶间孔和碳酸盐溶蚀孔及少量长石溶蚀孔,孔径为100~400 nm的孔隙面孔率贡献最大,多数页岩均接近100%。随着TOC含量增高,有机孔孔径减小,其面孔率则先增大后减小,TOC为5.5%时常出现拐点。龙马溪和龙一段页岩孔隙由下至上,面孔率逐渐降低。平面上,龙一11小层不同地区面孔率大小及孔隙组成也存在差异,泸州地区面孔率最大,渝西地区最低。渝西地区无机孔含量最高,长宁地区无机孔含量最低。石英晶间孔隙度与石英含量呈正相关,溶蚀孔隙度与碳酸盐矿物含量呈正相关,这可能与石英抗压实能力强、碳酸盐矿物易于溶蚀有关。 相似文献
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噻吩系列化合物的形成机理模拟 总被引：4，自引：0，他引：4
通过模拟实验发现硫能和各种链状化合物反应形成噻吩系列化合物。其反应机理可能是：硫先作用于链状化合物将其改造成共轭烯中间体,其他硫再从这个部位进入碳骨架从而形成该类化合物。硫还可进一步和噻吩系列反应形成更复杂的含硫芳烃,而温度升高会促进这种反应,所以噻吩系列的含量可以作为成熟度指标,在沉积条件相同的前提下,噻吩系列含量高指示成熟度低,反之则指示成熟度高。 相似文献
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四川盆地东南部及其盆缘转换带（以下简称渝东南盆缘转换带）是中国常压页岩气勘探的热点地区。为了厘清渝东南地区页岩气富集规律、优选水平井穿层层段及指导多层系立体开发建设,本文基于扫描电镜的图像定量表征技术,结合三轴力学、液氮吸附等实验分析结果,研究了页岩压力体系与有机孔的发育关系。结果表明：渝东南盆缘转换带五峰组—龙马溪组页岩下部①—②小层有机孔孔径小（1~30 nm）,孔隙发育的密集程度高（55.55~808.03个/μm2）;其上部③—⑤小层有机孔孔径变大（30~50 nm）,孔隙发育的密集程度低（47.31~466.42个/μm2）;压力系数与有机孔圆度有明显的正相关性。基于液氮吸附实验的孔隙体积分形维数结果表明,研究区龙马溪组页岩孔隙内流体压力的增加,能够对孔隙进行更好的支撑作用,保证孔隙不会因为上覆地层压力而造成变形,使得孔隙能够得到更好的保存。因此,有机孔发育差异是上覆地层压力和孔隙内流体压力共同造成的结果。对于常压区,上覆地层的压力对孔隙发育有着更为重要的影响;对于超压区,孔隙内流体压力的增加会减缓孔隙的变形和消失。三轴力学实验表明,①小层上部观音桥段的存在使得岩石的抗压强度变大,由此在纵向上形成一种压力隔断,引起了上下压力系数的差异,形成了不同的亚压力体系,从而导致了孔隙发育特征的差异。 相似文献
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地下水系统中有机物（OM）特征和活性对于地下水化学特征的形成和演化起着十分重要的作用。将内蒙古河套盆地表层湖相沉积物按10 cm间隔采集,并对沉积有机质的性质及来源进行重点分析。测量了不同深度上不同岩性沉积物的色度、水溶性有机物（WEOM）和盐溶性有机物（SEOM）含量及其光谱学特性。结果显示,沉积物的色度（R530-520）与TOC含量呈现相反的变化趋势:色度值较大时,TOC含量反而较小。相对于细砂层,黏土层的色度值较低,但TOC含量较高。相同的沉积物中,SEOM含量高于WEOM,但WEOM更易迁移至地下水中。有机物的光谱指数表明,WEOM以微生物来源为主,而SEOM以陆源为主。通过三维荧光光谱分析发现,荧光强度和沉积物有机碳（SOC）含量呈正相关;黏土层沉积有机物荧光强度更高;WEOM和SEOM均含类腐殖质成分和类蛋白成分,但SEOM中腐殖质成分较高;类腐殖质是所研究的沉积物中OM最主要的存在形式。 相似文献