高岭石-醋酸钾插层复合物的制备与表征

用XRD、FT-IR和TG-DSC等方法研究了高岭石-醋酸钾插层复合物的形成过程.XRD谱显示高岭石的层间距由0.72 nm增大到1.42 nm.这表明醋酸钾已经成功地插入到高岭石层间.FT-IR谱表明醋酸钾可能与高岭石的内表面羟基形成了氢键.TG-DSC谱表明,高岭石-醋酸钾插层复合物很稳定,直到大约400℃时,醋酸钾才从高岭石层间脱嵌出来.研究结果还证明水也和醋酸钾一起插入到了高岭石层间.     

高岭石声化学插层的XRD研究

以乙二醇、二甲基甲酰胺、二甲基亚砜及双氧水/冰醋酸等为插层剂,采用声化学法对高岭石进行了插层研究,考察了插层剂种类对高岭石插层率的影响.在此基础上,重点研究了以二甲基亚砜作为插层剂的情况下超声波功率、插层时间及插层剂的质量分数等工艺因素对插层率的影响,并采用XRD分析方法测试了高岭石的插层效率.结果表明：二甲基亚砜作为插层剂时插层率最高,插层率可达100%,二甲基甲酰胺和乙二醇次之,双氧水/冰醋酸插层率最低,插层率仅为14.9%.以二甲基亚砜为插层剂时,随着超声功率的增大,插层率先升高后降低;随着插层时间的延长,插层率呈增长趋势,而二甲基亚砜的质量分数对插层率的影响不大.在二甲基亚砜质量分数为75%、超声功率为300W、插层时间为2h的条件下,插层率达到100%,高岭石层间距从0.71nm被有效增大到1.10nm.     

高岭石/聚丙烯腈复合物原位合成SiC_w/Al_2O_3复相陶瓷粉体

在高岭石/二甲基亚砜插层复合物基础上,以醋酸铵对二甲基亚砜进行置换,进一步扩大了高岭石的层间距,使得丙烯腈单体得以顺利插入高岭石层间,并通过原位聚合的方法获得了高岭石/聚丙烯腈复合物。以该复合物为原料,在1 400℃合成碳化硅晶须/氧化铝复相陶瓷粉体,其中碳化硅晶须的直径≤200nm,长度≥15μm。     

微波对制备高岭石插层作用的研究

为了明确微波对制备高岭石插层的作用,采用乙酰胺对高岭石的微波熔融插层和油浴熔融插层进行了对比实验.借助于XRD、FTIR等分析测试手段,通过对比不同时间段2种插层环境下的插层率,分析了微波对插层反应的影响,进而探讨了微波对插层反应的作用机理.研究发现在反应初期微波对插层反应起促进作用,但随着时间的延长这种促进作用减弱,并呈现出一定的阻碍作用,认为是微波对乙酰胺的热作用和极化作用综合作用的结果.     

微晶高岭石/环氧树脂复合改性水性聚氨酯的研究

用十六烷基三甲基溴化铵,十二烷基三甲基溴化铵,对微晶高岭石进行有机化处理,得到有机微晶高岭石;以有机微晶高岭石、环氧E-51复合改性,制备了有机微晶高岭石/环氧树脂复合改性的水性聚氨酯（OMMT/E-51WPU）。研究了有机微晶高岭石、2,2-二羟甲基丙酸和环氧E-51的质量分数对乳液及涂膜物化性能的影响。结果表明：当w（OMMT）=1.5%,w（DMPA）=4.0%,w（E-51）=4.0%,乳液及膜的物化性能较好,乳液呈透明蓝光,吸水率为5.9%,接触角98°,拉伸强度32MPa,断裂伸长率571%。     

高岭石的脱水动力学研究

本文对一定粒级分布的高岭石的脱水反应进行了研究,研究表明高岭石的脱水反应级数与加热速度有关,并首次发现不同温度有不同的脱水量,说明了高岭石的脱水过程是跳跃式的,且其脱水是由水的层间扩散和水的形成共同控制的。     

高岭石/醋酸钾夹层复合体的制备与表征

论述了高岭石/醋酸钾复合体的制备、表征方法及夹层作用的影响因素。对目前在制备高岭石/醋酸钾复合体过程中存在的主要问题进行了分析。通过比较,指出了今后在合成高岭石/醋酸钾复合体过程中应注意的事项。     

高岭石／醋酸钾夹层复合体的制备与表征

论述了高岭石／醋酸钾复合体的制备、表征方法及夹层作用的影响因素。对目前在制备高岭石／醋酸钾复合体过程中存在的主要问题进行了分析。通过比较，指出了今后在合成高岭石／醋酸钾复合体过程中应注意的事项。     

夹层高岭石的热稳定性试验研究

本文利用热分析（ＴＡ）、红外光谱分析（ＩＲ）和Ｘ－射线衍射（ＸＲＤ）等手段研究煤系高岭石与醋酸钾合成夹层复合体的热稳定性。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，在此阶段发生脱羟基作用。复合体脱羟基所需的温度比纯高岭石发生同样作用所需温度要低得多，研究红外光谱发现，高岭石复合体中不同性质的羟基团的脱羟作用的发生，遵循着一个固定的顺序。     

硅烷对高岭石表面选择性修饰制备乳液稳定剂的研究

基于高岭石硅氧四面体和铝氧八面体表面性质的差异,采用乙烯基三甲氧基硅烷( vtms) 对高岭石表面进行选择性修饰,制备高岭石乳液稳定剂,研究其对水/石蜡乳液体系稳定性的影响。结果表明,温度是影响修饰作用的主要因素,在40 ～ 80 ℃,vtms 修饰高岭石的接触角为93° ～ 161°,通过控制修饰温度可以调节高岭石的润湿性。高岭石八面体表面Al-OH 基团与vtms 水解后的Si-OH 基团形成化学接枝。选择性修饰作用提高了高岭石颗粒的极性特征( Janus 效应) ,具有Janus 特征的高岭石具有良好的乳液稳定作用,乳液中乳状液含量达80%,分散相液滴平均粒径为20 μm,且分布均匀,乳液存放90 天后稳定性好。选择性修饰高岭石对乳液类型( 水包油( O/W) 型乳液或油包水( W/O) ) 具有调控作用。     

一种硬质高岭岩剥片实验研究

以醋酸钾作为插层剂制备高岭石-醋酸钾复合体,高岭石层间距从0.714nm增大到1.42nm,夹层率为80%。利用复合体的结构不稳定性,进行功率超声剥片。讨论了在一定功率超声场中,浆液体积、浆液浓度和超声时间对剥片作用的影响。实验结果表明:在输入功率为150W、变幅杆断面直径100mm、超声频率为18kHz的条件下,浆液体积为200mL、浆液浓度为10%、超声时间为15min时超声剥片的效果最佳。声空化作用产生的冲击波、质点产生的巨大加速度是引起高岭石-醋酸钾插层复合体顺层剥离的根本原因。在声空化作用下,浆液中高岭石颗粒间的高速碰撞使其颗粒进一步变细。     

Highly effective delamination of kaolinite and emergence of a novel nanoclub-like crystal

The delamination of kaolinite was performed via the combination of intercalation and sonication. The morphology including shape, size, and crystal structure before and after the treatment were investigated by using XRD, SEM, TEM and SED （selective electron diffraction）. The results not only show that the particle size is significantly reduced after short time sonication treatment, such as BET area up to 52.29 m^2/g after only 1 h sonication treatment, but also indicate that the treated particles keep good crystal structure. A new aluminum silicate nanoclub-like crystal formed after sonication treatment.     

Interface Characteristics Between Colloidal Gold and Kaolinite Surface by XPS

The distribution of gold colloids in kaolinite and the interaction between gold and kaolinite surface were investigated by transmission electron mieroscotgy （TEM） and X-ray photoelectron spectroscopy （ XPS ）. There is strong interaction between the gold particles and the edge surfaces of kaolinite, in low pH solution, the edge surface of kaolinite is positively charged and electrostutic attrcactive force between colloide gold panicles and the positive edge surface of kaolinite woald facilitate the adsorption of colloidal gold particles onto the suface. TEM observation shows that the aggregate morphology of gold particles was dominated by particle-particle interaction and gold particles were adsorbed on the edge surface of kaolinite crystals , resulting from the electrostatic attractive force between colloidal gold particles and the positice surfaces of kaolinite. XPS data show that in Au4 f electron spectra there are four energy peaks related to gold, 83.8 eV, 85.7 eV, 87.5 eV, and 89.4 eV, respectively, which suggests that in chemical states there are metallic gold and Au bonded to O, similar to the form of Au2O3 , and composite Au2O3 is formed between the edge surface of kaolinite and colloidal gold surface.     

硬质高岭石(岩)的功率超声剥片及作用机理

摘要：先制备了符合功率超声剥片需要的煤系高岭石样品,再选定不同高岭石浓度、超声作用体积和超声时间进行了高岭石超声剥片试验。探讨了剥片过程中的高岭石浓度、超声作用体积和时间等因素对高岭石剥片的影响,发现只有选取合适的浓度、体积和作用时间才能得到理想的剥片效果。对超声剥片机理进行理论分析,给出了空化阀值压力PB、液体表面张力 、空化气泡崩溃时的瞬态压力和瞬态温度等的数值关系。     

A series of aminoamides used for flotation of kaolinite

N-(2-aminoethyl)-dodecanamide, N-(3-dimethylaminopropyl)-dodecanamide, and N-(3-diethylaminoproyl)-dodecanamide used as collectors were studied for the flotation of kaolinite in the absence of additives at different pulp pHs as well as different collector contents. The effectiveness of the long chain aminoamides on pure kaolinite was demonstrated in laboratory scale flotation tests. The adsorption mechanism of the aminoamides onto kaolinite was investigated through zeta potential determinations and infrared spectrometry. The -98 μm size fractions of kaolinite, taken from Jiaxian Henan of China, were used in flotation. The hydrophilic group size of the aminoamides has a relatively less influence upon the floatability of pure kaolinite. The results suggest either the static-electric force or the coordinating bond adsorption mechanism of the aminoamides onto kaolinite depends on pulp pH.     

Research on Kaolinite in Coal Measures of West Beijing by Mossbauer Spectroscopy

The spatial occurrence of iron in kaolinite of coal measures west of Beijing was studied by using the Mossbauer spectroscopy technique and a step-by-step method of fitting. The results show that there are three kinds of spatial occurrence in kaolinites： tetra-coordination Fe（3＋） in Si-O tetrahedrons, sexa-coordination Fe（3＋） in A1--O octahedrons and sexa-coordination Fe（2＋） in A1-O octahedrons, respectively occupying 51.72 %, 37.25 % and 11.03 %, Neither foreign matter of magnetic Fe mineral nor superparamagnetic goethite exists in kaolin concentrates. Fe in kaolin concentrates cannot be removed by conventional methods, which is significant for both theoretical research on kaolinite minerology and practical use of the kaolinites of coal measures west of Beijing.The research also illustrates that the Mossbauer spectroscopy is an effective method in studying the micro-superfine Fe in kaolin.     

纳米高岭土颗粒改性水泥基复合材料的性能

研究了纳米高岭土颗粒对不同龄期水泥基材料微观结构（微孔结构、微观结构）及物理力学性能（工作性、抗弯强度、抗压强度、氯离子渗透性）的影响。结果表明,纳米高岭土颗粒的填充效应及其对水泥水化的促进作用改善了水泥基材料的微观孔结构,限制了氯离子在水泥基材料中的渗透扩散。当高岭土为水泥质量的1％时,水泥浆1、3、7、90 d抗弯强度分别提高30．41％、39．04％、36．27％和38．32％;当高岭土为水泥质量的5％时,水泥砂浆氯离子扩散系数降低53．03％;混凝土氯离子扩散系数随高岭土掺量增加呈指数递减;当高岭土为水泥质量的5％时,氯离子扩散系数降低18．87％;抗压强度分别提高28．4％;改性混凝土28 d抗压强度与混凝土氯离子扩散系数呈线性增加关系。