有机蒙脱石层间烷基铵吸附定量表征的研究

借助差热分析、热重分析等分析手段,研究了有机蒙脱石的热性能以及烷基铵在层间的吸附方式,建立了一种烷基铵层间有效吸附量定量分析的方法.热重分析表明,有机蒙脱石和钠蒙脱石的热性能不同,钠蒙脱石可以吸附更多的层间水,有机蒙脱石中吸附的烷基铵在230～480℃之间时完全分解.通过烷基铵层间吸附量的定量分析模型,可以根据改性剂的用量和烧失量,准确的计算出烷基铵的有效吸附率和有效摩尔吸附量.     

烷基铵在蒙脱石层间的吸附及其对蒙脱石/烷基铵的性能和结构的影响

本文以钠基蒙脱石和不同碳链长度的烷基季铵盐为原料,研究了烷基铵用量、插层反应时间、烷基铵的碳链长度对烷基铵吸附量、蒙脱石/烷基铵的凝胶性能和结构的影响。研究结果表明,烷基铵在蒙脱石层间的吸附量是影响蒙脱石/烷基铵凝胶性能和结构的主要因素,烷基铵在蒙脱石层间的吸附能够呈现出超量吸附的特性,而吸附量的变化则会导致蒙脱石/烷基铵凝胶性能的显著差异;受制于烷基铵在蒙脱石层间的吸附量和排列方式,蒙脱石/烷基铵的结构具有不确定性,随着烷基铵吸附量和排列方式的不同而呈现动态变化的特点。     

十六烷基氯化吡啶改性膨润土的制备及表征

采用十六烷基氯化吡啶(CPC)对甘肃平凉产天然膨润土(钙基)进行了改性。对制得的有机土进行了红外光谱、X-射线衍射、热重分析以及分散性实验,分析结果表明插层剂已进入蒙脱石的片层间,有机蒙脱石的层间距由1.43nm增加到2.11nm,N2气氛下热失重率可达17%;沉降实验表明这种改性膨润土在有机介质中表现出很好的分散性,这为进一步开发西部资源提供了实验室依据。     

微波法制备有机膨润土

用季铵盐、有机胺和复合试剂在微波场中对钠基膨润土进行有机化,制备了不同类型的有机蒙脱石,有机化时间由常规的2~3h减至15m in。XRD分析表明,蒙脱石的层间距由1.21nm增大至1.71~4.43nm;TG-DTG测试表明,蒙脱石层间的有机物在300~310℃分解,失重≥30%,均说明有机物已进入蒙脱石层间。     

钙基膨润土的有机化及其表征

以河北保定天然钙基膨润土为原料,经过提纯、钠化处理,再用十六烷基三甲基溴化铵进行了有机化改性,并采用X-ray衍射分析(XRD)、红外光谱分析(IR)和热分析(DSC、TG)等测试手段对其进行了表征。结果表明:钠化蒙脱石层间距离由1.512nm缩小到1.362nm,有机化蒙脱石层间距由1.362nm扩大到2.200nm;钠离子和十六烷基三甲基溴化铵已进入了蒙脱石的层间;钠化蒙脱石失去结构水的温度由632℃上升到647℃,而有机化蒙脱石在70~700℃温度范围内质量损失了30%。该方法有机化效果明显,实现了天然钙基膨润土到有机化蒙脱石的制备。     

蒙脱石层间烷基铵吸附量的测定

烷基铵在蒙脱石层间的吸附量是影响改性效果的决定因素.本文介绍了几种确定蒙脱石层间烷基铵吸附量的方法,着重介绍了通过烧失量计算烷基铵吸附量的方法,并采用该法分析了不同结构和用量的烷基铵在蒙脱石层间的有效吸附量和有效吸附率的变化.     

聚乳酸／有机蒙脱石纳米插层复合材料的制备及表征

以乳酸制备的丙交酯和有机蒙脱石为原料,通过原住插层聚合法制备了聚乳酸/有机蒙脱石纳米插层复合材料.分别采用傅立叶变换红外光谱、X射线衍射、透射电子显微镜、热重分析等对聚乳酸/有机蒙脱石纳米插层复合材料的结构、形貌及热稳定性进行了表征和分析.同时研究了材料的降解性能.研究表明,有机膨润土在聚合过程中被剥离成很小的粒子,并分散在聚乳酸基体中,形成聚乳酸/有机蒙脱石纳米插层复合材料.其蒙脱石层间距为2.439nm,层间距明显增大,表明聚乳酸分子链插入到蒙脱石片层间.实现了原位插层聚合,并形成了插层型结构.材料的热失重曲线移向高温端,其热分解温度提高,热稳定性比纯PLA有明显的提高.在不同介质中降解结果表明,材料在碱液中降解速率最快.     

介孔型硅柱撑蒙脱石的制备及表征

利用溶剂化作用,将辛胺和正硅酸四乙酯同时插层进入十六烷基三甲基有机阳离子型蒙脱石层间,在辛胺的碱性催化作用下,正硅酸四乙酯在蒙脱石层间原位水解得到硅酸及有机物混合插层蒙脱石.将此混合插层化合物在550℃煅烧后得到硅柱撑蒙脱石.用TG-DTA、XRD、TEM和N_2吸附-脱附等技术对所制备的硅柱撑蒙脱石进行了表征.结果表明:蒙脱石经硅柱撑后其比表面积由原始的80m~2/g增大到667m~2/g,孔容达到0.7413cm~3/g,具有介孔结构.     

复合改性蒙脱石/抗菌聚氨酯的制备及性能研究

蒙脱石经硝酸银和十六烷基三甲基溴化铵改性后与聚氨酯复合制成抗菌材料.采用XRD对改性前后蒙脱石的结构进行了分析和表征,采用抑菌圈法对样品进行了抗菌性能检测和研究.结果表明,硝酸银和十六烷基三甲基溴化铵复合改性蒙脱石,可以形成不同面网间距的层状结构.十六烷基三甲基铵离子插层率达到59％,络合银离子插层率达到38％,两者协...     

胺类/蒙脱石复合体的晶体结构研究

4称种胺类分子与蒙脱石形成有机复合体.用X-射线粉晶衍射仪对蒙脱石有机复合体的层间域特征进行表征,根据有机分子理论结构,对这4种有机物在层间的分布状态进行推测,二乙三胺、三乙四胺分子以单层平躺状居于蒙脱石层间,苯胺和对硝基苯胺是以垂直于硅酸盐层的方式存在于蒙脱石层间.     

China rare earth market review

正November 1~10,2014Chinese rare earth market was still inactive.Demand for rare earth products was weak.Consumers took a wait-and-see attitude for lower price.As it was an off season for rare earth products,it was expected that prices of rare earth could continue turbulence at the bottom in short terms.Due to a sharp drop,demand for rare earth from downstream recovered.Affected by new energy vehicles,wind powder and energy-efficient appliances,production of rare earth permanent     

China rare earth market review

正August 1~10,2014 There was some good news in rare earth industry recently.Restructuring plans of rare earth groups led by Baotou IronSteel Group and Xiamen Tungsten Group respectively have been approved by MIIT.And rare earth storage policy,which had been expected for a very long time,has been launched officially.Pushed by the good news,rare earth price started to rebound since August 5.Price of didymium oxide and dysprosium oxide rose about 1% to 2%,averagely.About 10% of     

China rare earth market review

正July 1~10,2014Due to weak demand from downstream industry and slow transactions,rare earth market remained weak and price of rare earth products continued to decline.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,     

New energy vehicle:an opportunity for rare earth magnets

<正>Extracted from Securities Guide 1.Popularity of new energy vehicles—an irresistible market trend1.1 Progress of new energy vehicles Chinese Premier Li Keqiang said recently on a visit to Xi'an BYD Autos that new energy vehicles,especially new energy bus,can lessen environment and noise pollution.He encouraged the use of new     

注浆加固技术在十三矿-685 m进风大巷中的应用

针对煤矿开采深度不断向深部延伸，掘进巷道受深部高应力的影响越来越大，巷道围岩整体稳定性差，矿山压力显现越剧烈现象，一般锚网喷加锚索支护无法从根本上控制巷道的变形。总结了平煤股份十三矿-685 m进风大巷注浆加固技术，依据对巷道掘进之后变形监测数据的采集，对巷道变形机理进行分析研究，并对注浆时段进行了合理选择，在对巷道的注浆工艺进行了充分论证的基础上，对巷道进行了注浆。注浆后效果表明:巷道滞后注浆时间段的选择非常重要，巷道在恰当的时间内进行注浆加固施工，能有效控制巷道的变形，巷道注浆后变形量明显减小，岩体的稳定性明显增强，减少了巷道日常维修工作，降低了矿井的生产成本，保障了矿井的安全生产。     

Brief news

正China Minmetals Rare Earth Construction of Jianghua Separation Plant is set to complete at the yearend Civil works of Jianghua Separation Plant have been finished and the company is installing and debugging equipments now.It is estimated that construction of Jianghua Separation Plant will be     

Brief news

正Total transactions of rare earth in Rare Earth Ex-change Center of Hunan South Rare and Precious Metal Exchange neared 40 billion yuan from January to October From the opening in January of this year to the end of October,the total transaction of rare earth products in Rare Earth Exchange Center of Hunan South Rare and Precious Metal Exchange neared40 billion yuan.There are 16 varieties including dysprosium oxide and terbium oxide traded on the exchange center,one of the largest trading platforms for rare earth oxides in China.     

Theoretical basis for optimal collector concentrations and pulp pH values during flotation of sulfide-free minerals

A hypothesis that associates optimal conditions of mineral flotation with a zero charge of their surface is put forward. This hypothesis serves as a basis for a methodology to obtain and verify quantitative physical-chemical models for a minimal necessary concentration of a collector during flotation of sulfide-free minerals. These models may be of use for upgrading engineering processes of flotation and as a job for the concentration plant automation systems. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 89–99, March–April, 2006.     

基于LPWAN技术的采煤沉陷区杆塔倾斜监测系统

随着地下采煤活动不断加大，越来越多的输电杆塔不可避免地被建设在煤矿沉陷区。目前，现有手段采用靠人力去进行定期检查一定会浪费大量的人力和物力，因而需开展对位于煤矿沉陷区的杆塔进行实时在线检测。基于NB-IoT和LoRa提出了一种新的算法——低功耗广域网（LPWAN）技术，提出了一种新型的输电杆塔倾斜监测系统，其中包含1个主节点和多个子节点，以适应地域广和远距离的需求信息监控。该系统通过LoRa多节点网络的数据传输，将杆塔的倾斜参数通过NB-IoT上传至在线实时监控系统。管理人员可以从后台得出监测数据并分析结果，及时对处于煤矿沉陷区的有故障的输电杆塔进行针对性的维护。     

基于AutoCAD的复杂曲线绘制的实现

介绍了如何利用其他软件在AutoCAD中精确绘制各种不同规划曲线的技巧 ,很好地解决了在AutoCAD中绘制多义线方法形成复杂曲线的误差问题 ,取得了较好的效果 ,具有实际意义。