集成回填材料的压实性能研究

核工业的生产会产生大量的核废物,如何安全处置这些核废物尤其是高放废物(HLW)日益成为摆在人类面前的严峻问题。本文通过轻型、重型压实实验得出击实功是影响压实性能的一个重要因素;添加一定量沸石或凹凸棒石可以得到较大的最大干密度和较小的最优含水率。在沸石或凹凸棒石添加为0～20%时混合材料的干密度增加不大,压实曲线相对平缓;随着沸石或凹凸棒石增加到20%～50%时,压实干密度急剧增大,但考虑到增加沸石或凹凸棒石超过50%时所需的压实功较大,因此沸石或凹凸棒石的含量在20%～30%较容易压实。     

热改性凹土复合聚丙烯酰胺絮凝剂在受污河水处理中的应用

热改性凹土复合聚丙烯酰胺合成新型复合絮凝剂,通过FT-IR红外光谱分析,热改性凹士与聚丙烯酰胺进行了有效接枝聚合.复合絮凝剂对受污河水的COD和浊度的去除实验结果表明,复合絮凝剂投加量50 mg/L时,受污河水的COD和浊度的去除效果最好,COD的去除率达到45.6％,浊度的去除率达到66.3％,复合絮凝剂中凹土和PAM协同效应显著.     

凹凸棒土与纳米二氧化硅对高强石膏浆体3D可打印性的影响

本文研究了凹凸棒土(ATP)和纳米二氧化硅(NS)对3D打印用α半水石膏浆体泵送性、流变性、支撑性等可打印性及固化体力学强度的影响。结果表明,掺入ATP后,泵送力维持在(0.57±0.02) kN,浆体剪切应力与剪切应变曲线不随掺量增加而发生明显变化,0 h、4 h打印体坍塌角分别从空白组的24°、32°降至掺量为2.8%(质量分数,下同)时的8°、11°。与ATP相比,打印浆体掺加NS后泵送力明显增加,掺加2.8%NS浆体的泵送力是同掺量ATP浆体的近2倍,浆体剪切初始应力随NS掺量增加而增大。虽然掺加NS使浆体泵送阻力增大,NS较ATP对打印体的支撑性却明显提升,掺加2.8%NS打印体0 h、4 h均无明显坍塌。ATP和NS在1%~2%掺量时浆体均可打印,且固化打印体抗压强度均有所增加,但层间粘结强度均削弱约2/3。     

Morphological characterization of attapulgite/poly(methyl methacrylate) particles prepared by soapless emulsion polymerization

BACKGROUND: The synthesis of core–shell inorganic/polymer nanocomposites, in which the polymer shell determines the chemical properties and the interaction with the environment, whereas their physical properties are governed by both the size and shape of the inorganic core and the surrounding organic layer, is an area of increasing research activity. RESULTS: Core–shell and bead–string shaped attapulgite/poly(methyl methacrylate) (ATP/PMMA) nanocomposite particles were prepared by soapless emulsion polymerization in an aqueous suspension of attapulgite organically modified with cetyltrimethylammonium bromide. CONCLUSION: Transmission electron microscopy analysis results showed that the amounts of the monomer added had no influence on the morphologies of the ATP/PMMA particles. The morphologies only depended on the length/diameter ratio of the attapulgite fibrillar single crystal used. Long ATP needles formed the bead–string structure while short ATP needles formed the core–shell structure. Copyright © 2007 Society of Chemical Industry     

Sulfur coating of urea treated with attapulgite clay

A commercial attapulgite-type gelling clay was added as a conditioning-hardening agent to urea which was then tested as a substrate for sulfur coating. The coating tests were made in bench-scale batch equipment. The total coating weights and the 7-day dissolution rates of the sulfur-coated products were determined and compared with those from similar tests of previously made sulfur-coated urea products containing calcium lignosulfonate or formaldehyde. Compared with urea substrates containing formaldehyde, the urea containing attapulgite clay required about one-third less sulfur coating to attain the same 7-day dissolution rate. The urea containing attapulgite clay and the urea containing calcium lignosulfonate were about equally effective as substrates for sulfur coating.     

改性凹凸棒石对碱性蓝54的吸附试验研究

用静态吸附法研究了改性凹凸棒石对碱性蓝54的吸附特性,探讨了初始pH值、温度以及染料初始浓度等因素的影响。结果表明吸附动力学较好地符合Lagergren二级吸附速率方程。利用两种等温线方程对吸附过程进行拟合,显示不同温度下的吸附等温式都与Langmuir方程符合。热力学分析表明,吸附过程吸热,吸附焓变△H和熵变△S均为正值,吸附自由能变△G为负值。     

聚吡咯/凹凸棒石纳米复合材料的制备及导电性能

以三氯化铁(FeCl_3)为氧化剂,十二烷基磺酸钠(sodium dodecylsulfonate,DSNa)为掺杂剂,使吡咯单体(pyrrole,Py)在凹凸棒石(attapulgite,ATP)的表面发生原位聚合反应,制备出聚吡咯/凹凸棒石(polypyrrole/attapulgite,PPy/ATP)纳米导电复合材料.研究了毗咯用量、聚合温度、聚合时间、FeCl_3用量以及DSNa用量对纳米导电复合材料体积电阻率的影响,确定了制备纳米导电复合材料的工艺条件.通过X射线衍射、热重-差热分析、Fourier红外光谱、Raman光谱和透射电子显微镜对纳米复合材料进行表征,结果表明:当吡咯用量(以ATP的质量计)为30%,FeCl_3与Py的摩尔比为2.3,DSNa的浓度为0.02g/mL时,20℃反应3h得到的PPy/ATP复合材料的体积电阻率可达7Ω·cm,聚吡咯以非晶态形式存在于凹凸棒石表面,两者之间的作用为物理作用.     

凹凸棒粘土及其在纺织印染中的应用

介绍了凹凸棒粘土的基本结构和特性(吸附特性、流变性、可塑性、离子交换能力、催化性、填充性、化学特性)、各种改性方法(热处理法、酸化法、偶联剂处理法、阳离子表面活性剂处理法、超声波分散法、微波处理法)及在不同领域的应用情况,叙述了凹凸棒粘土在纺织印染行业(涂料、高分子材料、纺织印染加工、印染废水处理)中的应用.     

改性凹凸棒石在樱桃果酒澄清中的应用研究

研究经硫酸处理的凹凸棒石对樱桃果酒的澄清效果及贮存的稳定性.考察了改性凹凸棒石的添加量、澄清温度、处理时间对樱桃果酒的澄清作用.通过响应面法确定樱桃果酒的最佳澄清工条件为酸改性凹凸棒石添加量6.0g/L、澄清温度25℃、澄清时间11h,在此条件下获得樱桃果酒的澄清度为93.4％,果酒的稳定性好.