共查询到19条相似文献，搜索用时 828 毫秒
1.
根据表面活性剂特殊分子结构,以顺磁性材料为磁核,在其表面先后覆盖内层、外层两层表面活性剂的单分子膜。由于外层表面活性剂亲水基因的吸附而使磁化剂与椰壳活性炭键合在一起,因此活性炭被赋予磁性。对磁化剂用量、pH、活化剂等因素对椰壳磁性活性炭磁化率影响也进行了研究。最后确定椰壳磁性活性炭的最佳合成条件为 MR-20为最佳磁化剂、活化剂浓度为0．02M,pH为2～3,椰壳磁性活性炭的物理性质随磁化剂的用量以及具体的磁化条件不同而不同。 相似文献
2.
活性炭改性方法的研究进展 总被引：7，自引：0，他引：7
从活性炭的表面结构和表面化学性质两方面介绍了活性炭改性方法的研究进展,概述了活性炭性质的表征方法,用于比较活性炭改性前后的吸附性能,并总结了不同吸附质常采用的改性方法。 相似文献
3.
林燕 《福建工程学院学报》2017,(1):9-14
采用氨水浸渍法对果壳活性炭进行改性处理,讨论不同氨水浓度（5%、10%、15%、20%）对果壳活性炭结构及性能的影响。采用场发射扫描电镜、比表面及孔径分析仪及紫外分光光度计对改性后的果壳活性炭结构及吸附性能进行研究。结果表明:氨水浓度对果壳活性炭的结构及吸附性能有显著影响,当氨水浓度为10%时,活性炭表面形态清晰,凹槽分布均匀,比表面积提高至775.1382m2/g,较改性前提高了6.5%;改性前后活性炭微孔孔径集中分布在3.5 nm;果壳活性炭的吸附率随氨水浓度的变化而变化,当氨水浓度为10%和15%时,吸附率分别达到86.51%和86.54%,吸附率相比改性前有所提高。而当氨水浓度进一步增加时,活性炭对苯酚的吸附率略微下降。 相似文献
4.
木炭或活性炭的吸附褪色：将烘烤过的木炭或活性炭投入充满红棕色二氧化氮的集气瓶里或滴有红墨水略显红色的水中，振荡，红棕色的二氧化氮气体或溶液的红色变浅或消失了。这是因为木炭或活性炭具有吸附能力，能把大量的气体或染料等微粒吸附在它的表面而使物质褪色，这属于物理变化。 相似文献
5.
不同类型表面活性剂与蛋白质作用研究进展 总被引：1，自引：0，他引：1
表面活性剂和蛋白质作用的方式与表面活性剂的种类、结构、浓度和其理化性质有关。本文系统地总结了多种类型表面活性剂(阴离子型、阳离子型、两性离子型、非离子型、氟表面活性剂及Gemini表面活性剂)的结构特点,以蛋白质-表面活性剂相互作用的物理化学特征为出发点,综述了该体系相互作用的最新研究成果及进展,包括二者作用时所形成的复合物的结构理论,复合物的吸附机理及其作用过程中蛋白质结构的变化;结合本课题组的工作总结分析了蛋白质分别与各类表面活性剂相互作用过程中作用力特征、相行为、作用机理及应用。 相似文献
6.
《中学课程辅导(初三版)》2007,(10)
活性炭是一种多孔性物质。具有高度发达的孔隙构造和巨大的表面积.每克活性炭的吸附面积相当于八个网球场之大,是世界公认的一种最优良的吸附剂。由于活性炭表面上含有多元素含氧官能团。还可以浸渍化学物质,制成浸渍活性炭。因此。它既是优良的吸附 相似文献
7.
刘亚强 《渭南师范学院学报》1993,(Z1)
本文用热力学方法证明在γ—α_1,α_2曲面上不会有最低值存在,论述了在CMC附近多组分表面活性剂溶液的表面张力和溶质活度随浓度的变化关系,以及表面吸附物的转变。 相似文献
8.
舒代宁 《乐山师范学院学报》1986,(2)
一、前言某些物质当它们以低浓度存在于一体系中时,可吸附在该体系的表面(界面)上,使这些表面(界面)的表面(界面)自由能发生明显降低的现象,这些物质被称为表面活性剂(Surface-active agent)。能在水溶液中发生电离的表面活性剂叫离子型表面活性剂。电离后,若疏水基团处于正离子部份的表面活性剂叫正离子表面活性剂,反之则叫负离子表面活性剂。表面活性剂可以起到去污、乳化、润湿、发泡和加溶等作用, 相似文献
9.
本文介绍了对危害极大的煤井低浓度甲烷的吸附增浓方式和吸附剂的研究进展。通过对比变压吸附分离CH4/N2的沸石分子筛、碳分子筛和活性炭三类吸附剂的优缺点,提出活性炭是较为理想的吸附剂。从理论探讨了活性炭的结构对吸附提浓甲烷性能的影响,进一步介绍了活性炭孔道结构的调控手段和表面化学结构的改性方式。 相似文献
10.
将碳酸钙颗粒分散于聚苯乙烯溶液中,并在石英晶体微天平（QCM）表面成膜,以稀盐酸将膜中的碳酸钙颗粒溶解,获得多孔的聚苯乙烯薄膜,以QCM动态传感监测表面活性剂在多孔膜上的吸附过程．结果表明,十二烷基苯磺酸钠、氯代十六烷基吡啶、TX-114均在聚苯乙烯薄膜上吸附,三种表面活性剂在多孔膜上的吸附动力学和等温线可以分别用Langmuir动力学和等温线模型回归分析,得到了有关吸附动力学参数和吸附等温线参数． 相似文献
11.
Enhanced degradation of carbon tetrachloride by surfactant-modified zero-valent iron 总被引：1，自引：0，他引：1
Sorption of carbon tetrachloride （CT） by zero-valent iron （ZVI） is the rate-limiting step in the degradation of CT, so the sorption capacity of ZVl is of great importance. This experiment was aimed at enhancing the sorption of CT by ZVI and the degradation rate of CT by modification of surfactants. This study showed that ZVI modified by cationic surfactants has favorable synergistic effect on the degradation of CT. The CT degradation rate of ZVI modified by cetyl pyridinium bromide （CPB） was higher than that of the unmodified ZVI by 130%, and the CT degradation rate of ZVI modified by cetyl trimethyl ammonium bromide （CTAB） was higher than that of the unmodified ZVI by 81%. This study also showed that the best degradation effect is obtained at the near critical micelle concentrations （CMC） and that high loaded cationic surfactant does not have good synergistic effect on the degradation due to its hydrophilicity and the block in surface reduction sites. Furthermore degradation of CT by ZVI modified by nonionic surfactant has not positive effect on the degradation as the ionic surfactant and the ZVI modified by anionic surfactant has hardly any obvious effects on the degradation. 相似文献
12.
B. S. Sekhon 《Resonance》2004,9(3):42-49
A gemini surfactant (GS) consists of two conventional surfactant molecules chemically bonded together by a spacer. The two
terminal hydrocarbon tails can be short or long; the two polar head groups can be cationic, anionic or nonionic; the spacer
can be short or long, flexible or rigid. The GS need not be symmetrically disposed about the center of the spacer. GS can
self-assemble at much lower concentrations and are superior in surface activity as compared to conventional surfactants. GS
are very attractive for catalysis and adsorption applications, new synthetic vectors for gene transfection, analytical separations,
solubilization processes, nanoscale technology, biotechnology, enhanced oil recovery and as paint additives. 相似文献
13.
14.
以仲钼酸铵和硝酸为原料,采用液相化学法制备超细MoO3.研究了表面活性剂类型及浓度对产物形貌的影响.结果表明,阴离子型表面活性剂的分散性能优于阳离子和非离子表面活性剂.在添加浓度为1.8mmol/L十二烷基苯磺酸钠(DBS)时,能够制备出分散性较好、粒径为100nm左右的球形超细MoO3粉末. 相似文献
15.
表面活性剂对复合电沉积法制备纳米碳管复合镀层的影响 总被引：2，自引：0，他引：2
采用复合电沉积法制备纳米碳管复合镀层,在控制实验基本工艺参数不变的条件下,通过加入不同的表面活性剂进行电镀,测量纳米碳管的质量占所得镀层总质量的百分比。经过分析后可以得到:阳离子表面活性剂更有利于制备纳米碳管复合镀层的电沉积;而阴离子表面活性剂以及非离子表面活性剂则不利于制备纳米碳管复合镀层的电沉积。 相似文献
16.
Interaction of nonionic surfactant AEO9 with ionic surfactants 总被引：2，自引：0，他引：2
INTRODUCTION Long chain nonionic surfactants such as poly-oxyethylenated alcohols C12H25O(CH2CH2O)9H (AEO9), are widely used in the chemical industry in fabric detergency and tertiary oil recovery due to their excellent surface-active properties. In many practical applications, surfactants are used in formulations containing mixtures of different compounds, and synergism can often be observed. Synergism is de-fined here as the condition in which the properties of a mixture are better… 相似文献
17.
《浙江大学学报(A卷英文版)》2021,(2)
In this study, the effects of five different ionic and nonionic surfactants on the physical properties and microstructures of a metakaolin-based geopolymer(MKG) were investigated. It is the first comprehensive comparative study of the effects of sodium lauryl sulfonate(SLS), alkyl polyglycoside(APG), benzalkonium chloride(BAC), sucrose fatty acid esters(SE), and stearic acid(STA) on MKG. Viscosity, densities, apparent water absorption, and compressive strength were measured, and pore structures, micro-defects, and gels observed through scanning electron microscopy(SEM) and mercury intrusion porosimetry(MIP). In the MKG slurry, a high affinity of surfactants to liquid-air interfaces increased viscosity and promoted the generation of bubbles. Based on both the ionic types and molecular configurations of the surfactants, stronger adsorption of a surfactant on the surface of the metakaolin resulted in better dispersion of metakaolin particles and a denser microstructure of the MKG. The surfactants with weaker adsorption(SLS and APG) caused higher porosity, a larger pore size, and more micro-defects, while those with stronger adsorption(BAC, SE, and STA) led to relatively lower porosity and denser microstructures. Density, water absorption, and compressive strength were closely related to the total intrusion porosity of the MKG. The mechanisms underlying surfactant adsorption to the surface of metakaolin are proposed. 相似文献
18.
In this work, the surface activity of block copolymer nonionic surfactants (RPE) has been determined, i.e., critical micelle concentration (CMC), surface excess concentration (Γ), surface area demand per molecule (A), surface tension at CMC (yCMC). A linear decrease of ln[CMC] vs number of oxypropylene units in copolymer molecule was observed. The change in the work of cohesion per oxypropylene group when passing from molecular into micellar state, calculated from the Shinoda equation, was 0.43kT for the studied compounds. 相似文献
19.
Effect of polyoxypropylene chain length on the critical micelle concentration of propylene oxide-ethylene oxide block copolymers 总被引：1，自引：0，他引：1
In this work, the surface activity of block copolymer nonionic surfactants (RPE) has been determined, i.e., critical micelle concentration (CMC), surface excess concentration (Γ), surface area demand per molecule (A), surface tension at CMC (γCMC). A linear decrease of in[CMC] vs number of oxypropylene units in copolymer molecule was observed. The change in the work of cohesion per oxypropylene group when passing from molecular into micellar state, calculated from the Shinoda equation,was 0.43kT for the studied compounds. 相似文献