活性氧化铝对水中F-的吸附特性及其影响因素

以活性氧化铝作为吸附剂,研究其对水中F-的去除性能,同时探究了吸附剂的投加量、温度、p H对吸附效果的影响。结果表明:活性氧化铝对水中的F-有较好的去除效果,符合准一级吸附动力学方程。用Langmuir方程拟合的最大吸附量为4.39mg/g (25℃)。反应的吉布斯自由能(ΔG)为-20.77～-22.05kJ/mol,说明吸附是一个自发的过程。活性氧化铝对水中F-的吸附量随pH的升高而降低,最佳应用pH为5～7;最佳投加量为2.0g/L;当外界温度从15℃增加到35℃时,吸附量增加了0.1～1.1倍,因此,活性氧化铝应用于北方高氟地下饮用水处理时,冬季应考虑附加增温、保温设施。     

改性活性炭的表面特性及其对苯酚的吸附性能

研究了表面改性对活性炭吸附苯酚性能的影响。研究发现,硫酸氧化可增加活性炭表面酸性基团的含量,提高了活性炭的表面亲水性,降低pHPZC值,因而对吸附水中的苯酚的性能产生明显影响,降低了对苯酚的吸附。     

改性木质素磺酸钙及其对氟离子(F-)的吸附研究

利用三亚乙基四胺(TETA)和聚乙二醇(PEG-400)对市售的木质素磺酸钙进行了改性,并研究了改性木质素磺酸钙对溶液中氟离子(F)的吸附行为.结果 表明,改性后的木质素对F表现出了一定的吸附能力.在实际吸附实验中,改性木质素对F-的平衡吸附量约为1.6 mg/g,理论饱和吸附量为2.17 mg/g.通过对改性木质素对...     

Gemini表面活性剂的吸附、自聚和性质

Gemini表面活性剂通常是由两 (或三 )条疏水链、两个亲水基和一个连接基组成的两性分(离 )子 ,与由单亲水基和单疏水基构成的单体表面活性剂分 (离 )子相比较 ,在临界胶团浓度、界面性质和溶解性等方面有着独特的性质。由于其电荷密度高 ,临界胶团浓度低 ,并且有很低的 Krafft点 ,能在低浓度下与高碳烷烃形成超低界面张力 ,在石油开发中有着很好的应用前景。详述了该类新型表活性剂的吸附、自聚、性质 ,比较了与单体表面活性剂的差别     

磷酸溶液中油酸钠在钢表面的吸附及缓蚀作用

用失重法及电化学法研究了阴离子表面活性剂油酸钠(SO)对冷轧钢在3.0 mol/L H3PO4溶液中的缓蚀作用.结果表明:油酸钠对冷轧钢具有良好的缓蚀作用,为阴极抑制型缓蚀剂,缓蚀率随油酸钠的浓度增加而增大,而随温度的升高而减小;油酸钠在钢表面的吸附在30℃和40℃时符合校正的Langmuir吸附模型,50℃和60℃时则符合Freundlich吸附模型.通过吸附理论和化学热力学基本公式求出了相应的吸附热力学参数(吸附自由能ΔG°, 吸附热ΔH°, 吸附熵ΔS°),并根据这些参数详细讨论了缓蚀作用机理.     

扩展球形溶液表面上decanoyl-N-methylglucamine的吸附动力学

A general expression of the dynamic surface adsorption [Г（t）] on the expanding spherical surface was derived by solving the corresponding diffusion equation under different initial and boundary conditions. Different from the result of the still spherical surface, two factors （smaller than 1） appeared in the equation for the short time adsorption. Using the derived results, the adsorption kinetics of aqueous decanoyl-N-methylglucamine （Mega-10） solution was studied. In the short time region （t→0）, a good agreement of experimental results with the theory was reached and the adsorption was controlled by diffusion.     

单溴四苯基卟啉吸附在AgCl溶液表面性质研究

合成了单溴四苯基卟啉－5－（邻溴苯基）－10，15，20－二苯基卟啉（H2L），用元素分析，红外光谱，电子吸收光谱和氢核磁共振谱确定了其组成和结构，研究了H2L在醋酸中电子吸收光谱和在AgCl溶胶上的表面化学反应，结果表明，单邻溴四苯基卟啉在冰醋酸中以二酸形式H4L^2 和游离碱H2L形式存在，二者之间存在着电离平衡：H2L^2 =H2L 2H^ ,当pH=7.0-11.0时，H2L在AgCl溶液表面发生配位反应生成Ag(II)L,并且溶液的pH增大，配位反应的速率增大。     

电解质溶液中表面活性剂控制吸附下液滴的速度

引　言Ｍａｒａｎｇｏｎｉ应力使液滴在充满表面活性剂的连续介质中运动比在洁净介质中运动慢得多 Ｄａｖｉｓ和Ａｃｒｉｖｏｓ[1]以及Ｓａｄｈａｌ和Ｊｏｈｎｓｏｎ[2 ]采用线性吸附模型从理论上研究了表面活性剂对液滴运动的影响 在假设活性剂不可溶且忽略其在液滴表面扩散的情况下 ,Ｋｉｍ[3]得到了受活性剂影响的液滴迁移速度的解析解 在考虑活性剂表面扩散的情况下 ,Ｋｉｍ[4 ]进一步研究了液滴的运动·陈晋南和Ｓｔｅｂｅ[5 ]采用非线性Ｌａｎｇｍｕｉｒ和Ｆｒｕｍｋｉｎ吸附模型 ,考虑了液滴与表面活性剂之间吸附单饱和及非理想相…     

钼尾矿中方解石、白云石分选试验研究

为了分离出钼尾矿基陶瓷掺料中的方解石、白云石矿物,以水玻璃为抑制剂、油酸钠为调整剂、十二烷基胺为起泡剂,采用浮选方法对辽宁某钼尾矿进行了试验研究,并采用热力学计算对油酸钠捕收方解石、白云石的机理进行分析.结果表明,油酸根以化学吸附形式与矿物表面Al3+、Ca2+、Mg2+形成难溶油酸盐,附着于目的矿物表面,调整油酸钠的添加量,可实现金云母、方解石和白云石的分选富集;pH＜ 8.87时,油酸根优先捕收金云母;pH ＞9.3时,油酸根优先捕收方解石和白云石.     

表面改性对活性炭吸附性能的影响

采用浓硝酸对活性炭进行表面氧化处理,将得到的样品分别浸渍在银氨、硫酸铜及咪唑溶液中进一步改性,然后采用Boehm滴定法对改性活性炭表面酸性基团的含量进行测定,研究改性对活性炭吸附性能的影响。结果表明：通过上述改性,活性炭表面酸性基团发生了显著变化,特别是羧基含量增加较多,从而活性诙的吸附性能发生了相应的变化。     

Competitive Adsorption of Basic Dyes onto Calcite in Single and Binary Component Systems

Equilibrium and kinetic behavior of two basic dyes, Methylene Blue (MB) and Safranine T (ST), onto calcite in single and binary component systems have been studied. Experimental equilibrium results have been well predicted by the Freundlich and the Langmuir isotherm models. The model parameters obtained for single solute systems at 298 K have been used for the calculation of adsorption isotherms in binary dye solutions using multi-component isotherm models. Extended Freundlich and extended Langmuir models satisfactorily fit to MB–ST adsorption in binary solutions. A site distribution function which gives information about the affinity of adsorption sites for competing species in a binary system has been mathematically calculated by using Freundlich isotherm parameters. Time-dependent results for single and binary dye solutions have been analyzed according to the Vermeulen and McKay models based on homogeneous and heterogeneous diffusion processes, respectively. Thermodynamic functions for the transition state have been evaluated from the temperature dependence of diffusion coefficients using the Eyring equation.     

表面过剩及吉布斯吸附等温式的探讨

物理化学中溶液表面吸附的表面过剩是一个可正可负的物理量，在部分的教材中，对表面过剩公式的表达不能反映其可正可负的情况，且因引入吉布斯吸附模型，对于公式的推导繁杂、理解困难，不便讲解。因此，有必要对此进行探讨，以便帮助教学和学习。     

焙烧水滑石表面酸碱性质及其吸附性研究

采用尿素法制备了锌-铝水滑石,并通过高温煅烧得到了焙烧水滑石。通过表面酸碱滴定实验进行了材料表面性质研究,并进行了吸附抗生素实验。结果表明,由于焙烧水滑石良好的质子化和脱质子化能力,从而与抗生素表面形成羟基,从而达到很好的吸附效果。     

凹凸棒土表面改性及其对聚丙烯力学性能的影响

使用硬脂酸钠、硅烷和钛酸酯偶联剂对凹凸棒土进行了表面改性,通过熔融共混法制备PP/凹凸棒土复合材料。借助FTIR、DSC、TEM、材料力学实验机等手段分别对凹凸棒土的改性效果、分散状态以及复合材料的结构与性能进行了研究。结果表明,适当的表面修饰有助于凹凸棒土在PP基体中实现以针状棒晶为基本形态的均匀分散;凹凸棒土在基体中提高了PP结晶度的同时提高了材料的强度和模量。     

表面吸附对JO-9159炸药力学性能影响的分子动力学模拟

为研究表面吸附对JO-9159炸药力学性能的影响,通过Materials Studio软件构建了JO-9159炸药无定形六组分模型,在COMPASS力场和NPT系综下,对其(0 0 1)、(0 1 0)和(1 0 0)3种晶面的表面吸附进行了周期性分子动力学模拟;基于模型的平衡轨迹对JO-9159炸药的力学性能进行了研究。结果表明,在295K下,吸附后其各向同性增长,刚性、硬度和断裂强度减小,柔韧性增强,压缩强度降低;随着JO-9159炸药表面吸附气体分子数量的增加,体系的各向异性减小,各向同性增长,刚性、硬度和断裂强度减小,柔韧性增强,压缩强度降低;在195~395K内,随着温度的升高,表面吸附后JO-9159炸药的各向异性特征降低,各向同性特征增强,刚性、硬度和断裂强度减小,柔韧性增强,压缩强度降低。     

反应时间对镁铝水滑石制备及其吸附性能的影响

采用共沉淀法制备镁铝水滑石,并利用XRD、SEM、FT-IR对反应产物进行表征,研究了反应时间对水滑石物相组成、微观结构和对盐酸四环素吸附性能的影响,对土壤污染治理和修复具有重要的现实意义.结果分析表明,当反应时间为12 h时制备的镁铝水滑石对盐酸四环素有较好的吸附效果,吸附率为70.82％.镁铝水滑石对盐酸四环素的吸...     

Utilization of sodium humate as selective depressants for calcite on the flotation of scheelite

The flotation separation of scheelite from calcite using sodium humate (SH) as a potential depressant has been studied through micro-flotation experiments, zeta potential and Fourier transform infrared (FT-IR) spectra measurements. The flotation results indicate SH exhibited selective depression effect on calcite in the presence of sodium oleate, achieving the flotation separation of scheelite from calcite. Zeta potential results indicate that SH strongly absorbed on calcite surface but negligibly on scheelite surface, which prevents the adsorption of sodium oleate on calcite surface. The FT-IR results also show that SH can be adsorb on the surface of calcite. Results shown a higher Ca density on the calcite than on scheelite surface, and that calcite can accommodate the interaction of SH.     

Adsorption characteristics of glycols on calcite and hematite

Monoethylene glycol, diethylene glycol, and triethylene glycol can be used for hydrate prevention during transport of liquids and gases, in dehumidifiers, for controlling growth of hematite nanoparticles and in the precipitation of different calcium carbonate morphologies. In all these applications, glycols may interact with calcite or hematite or both. Molecular dynamics and electronic structure calculations were used to investigate glycol adsorption on these surfaces. All glycols primarily adsorbed with hydroxyl hydrogen atoms to surface oxygen atoms. Glycol hydroxyl oxygen atoms coordinated toward surface calcium atoms and iron atoms of calcite and hematite, respectively. Glycols generally had a stronger affinity toward un-hydroxylated hematite. However, hydroxylation of hematite reduced the absolute value of glycol adsorption free energies considerably. Molecular conformations changed during adsorption, which affected the free energy profiles. Adsorbed glycols resulted in a dipole moment pointing away from the surfaces.