二乙烯三胺改性膨胀石墨吸附溶液中MoO_4~(2-)

以二乙烯三胺(DETA)为改性剂,对羧基化膨胀石墨(EG-COOH)进行表面修饰,制备了一种对MoO_4~(2-)具有选择性吸附能力的吸附剂EG-DETA。FTIR分析表明,膨胀石墨(EG)表面成功接枝上了二乙烯三胺(DETA)。考察了p H、初始浓度、吸附时间、外加电场对EG-DETA吸附MoO_4~(2-)效果的影响。结果表明,最佳的吸附条件为:1. 2 V的外加电场,初始浓度为450 mg/L,p H=4,吸附时间240 min。此时EG-DETA对MoO_4~(2-)的饱和吸附量为1 090 mg/g,洗脱率为64%。动力学研究表明,吸附过程符合一级动力学模型,吸附速率受扩散控制;热力学研究表明,吸附过程属于Langmuir单分子层吸附。     

MoO_4~(2-)与WO_4~(2-)的分离

研究了WO2-4、MoO2-4在Fe（OH）3上的吸附行为及其规律；揭示了WO2-4／MoO2-4分离的最佳条件；得出了MoO2-4在Fe（OH）3上的吸附符合Frendlich方程，具体表达式为г＝229c0.25，Wo2-4在Fe（OH）3上的吸附不符合一般的吸附规律，可能形成了钨铁化合物。     

膨胀石墨对SO2的吸附

通过ＳＯ２动态柱吸附实验分析了膨胀石墨对ＳＯ２的吸附脱除能力。通过静态热重分析得到等温和变温条件下的吸附特性。最后分析了膨胀石墨对ＳＯ２吸附的机理。     

膨胀石墨对有机化合物的吸附

研究了在水溶液中膨胀石墨对部分极性有机化合物的吸附特性，研究了有机物的极性、粘度、分子尺寸，溶解度、浓度和吸附剂比表面积等因素对吸附量的影响。     

改性膨胀石墨对甲醛的吸附性能研究

对含甲醛的废气处理一般采用吸附法，本文以天然鳞片石墨、浓硫酸、浓硝酸、双氧水、重铬酸钾为原料，采用改进的二次氧化法制备膨胀石墨，并对所制得的膨胀石墨进行表面改性。运用改性后的膨胀石墨对甲醛进行静态和动态吸附实验，实验结果表明，改性后的膨胀石墨对甲醛气体的吸附能力有大幅度提高。研究了改性前后膨胀石墨孔结构的变化及其对饱和吸附量的影响，并对改性机理进行了初步探讨。     

改性膨胀石墨的制备及其对Cr(Ⅵ)的吸附性能研究

以磷酸为活化剂、十六烷基三甲基溴化铵-溴化钾(CTAB-KBr)为复合改性剂,对膨胀石墨进行表面改性制备了高效吸附剂改性膨胀石墨(M-EG),通过SEM、FTIR对其结构进行了表征,优化了制备条件,并探究了其对Cr(Ⅵ)的吸附性能和吸附机理。结果表明,以40%磷酸为活化剂、2.9%CTAB-1.8%KBr为复合改性剂,55℃下,对膨胀石墨进行表面活化0.5 h和改性处理3 h,所制备的M-EG对Cr(Ⅵ)具有较高的吸附性能;在常温、pH≈5的条件下,80 mg·L^-1 Cr(Ⅵ)废水经4.5 g·L^-1 M-EG吸附120 min, Cr(Ⅵ)去除率可高达96.74%;吸附过程是自发的、放热的,遵循准二级动力学模型,在低温环境中更符合Langmuir等温吸附模型,在高温环境中同时符合Langmuir和Freundlich等温吸附模型。     

膨胀石墨对重油吸附特性的研究

用重量法研究了膨胀石墨对重油的吸附特性，并与活性炭进行了比较。讨论了表征吸附量的数学模型，对膨胀石墨大孔吸附机理进行了探讨．研究表明：以大孔为主的膨胀石墨吸附材料有良好的吸附重油的性能，明显优于活性炭。     

膨胀石墨的制备及其吸附性能

本文介绍了近年来人们在膨胀石墨的制备、吸附性能及机理研究等方面的成果。     

膨胀石墨对苯胺的吸附研究

苯胺对生物体的危害极大,是环境监测的一项重要指标。本文以膨胀石墨为吸附剂,研究了它对苯胺的吸附性能,主要探讨了苯胺溶液的浓度、时间及膨胀石墨粒度对吸附行为的影响。结果表明,膨胀石墨对苯胺具有较好的吸附效果,膨胀石墨对苯胺吸附的最佳浓度是400μg／mL,吸附90分钟就可以达到平衡,而且粒径为0．177-0．149mm的膨胀石墨对苯胺吸附量最大。     

膨胀石墨对苯胺的吸附研究

苯胺对生物体的危害极大,是环境监测的一项重要指标。本文以膨胀石墨为吸附剂,研究了它对苯胺的吸附性能,主要探讨了苯胺溶液的浓度、时间及膨胀石墨粒度对吸附行为的影响。结果表明,膨胀石墨对苯胺具有较好的吸附效果,膨胀石墨对苯胺吸附的最佳浓度是400μg/mL,吸附90分钟就可以达到平衡,而且粒径为0.177-0.149mm的膨胀石墨对苯胺吸附量最大。     

新固体酸SO4^—2—MoO3—TiO2催化合成癸二酸二丁酯

自制了一种新型固体酸催化剂SO4^-2-MoO3-TiO2，FT－IR分析表明，催化剂表面具有强酸中心，吸附吡啶的FT－IR表明，催化剂表面主要存在Broensted酸点，该催化剂对合成癸二酸二丁酯反应活性高，重复性好，考察了反应条件，并获得了该反应的优化条件。     

Adsorption of methylene blue from aqueous solutions by modified expanded graphite powder

The modified expanded graphite (MEG) powder was used as a porous adsorbent for the removal of the cationic dye, methylene blue (MB), from aqueous solutions. The dye adsorption experiments were carried out with the bath procedure. Experimental results showed that the basic pH, increasing initial dye concentration and high temperature favored the adsorption. The dye adsorption equilibrium was attained rapidly after 5 min of contact time. Experimental data related to the adsorption of MB on the MEG under different conditions were applied to the pseudo-first-order equation, the pseudo-second-order equation and the intraparticle diffusion equation, and the rate constants of first-order adsorption (k₁), the rate constants of second-order adsorption (k₂) and intraparticle diffusion rate constants (k_int) were calculated, respectively. The experimental data fitted very well in the pseudo-second-order kinetic model. The thermodynamic parameters of activation such as Gibbs free energy, enthalpy, and entropy were also evaluated. The results indicated that the MEG powder could be employed as an efficient adsorbent for the removal of textile dyes from effluents.     

中性体系中MoO_4~(2-)对碳钢垢下局部腐蚀的抑制作用

设计了一种能够模拟垢下局部腐蚀自催化过程的闭塞电池,采用极化曲线和电化学阻抗方法研究了MoO42-对N80钢在近中性NaCl溶液中闭塞区内化学及电化学状态变化的影响。结果表明,MoO24-能有效地减缓闭塞区内pH值降低及Cl-浓集、减弱酸化自催化效应、抑制垢下局部腐蚀。MoO42-的作用机制在于使水合氧化铁腐蚀膜由阴离子选择性变为阳离子选择性,H 可以从膜下扩散出去,而Cl-难以扩散到膜下富集,抑制了腐蚀反应的阴极过程;同时MoO24-迁入闭塞区后增大了电极表面膜层阻抗,抑制了腐蚀反应的阳极过程。     

工业循环冷却水中钼酸盐类缓蚀剂MoO_4~(2-)测定方法的改进

准确调节被测样液的pH值为3.4～3.6,用G4砂芯滤器或慢速滤纸干过滤被测样液,控制样液MoO_4~(2-)待测浓度在3～5μg/mL,取样液体积为5～20mL。给出了适宜的MoO_4~(2-)工作曲线,并对其可靠性和高浓度Ca~(2+)、Mg~(2+)等阳离子对测定的干扰进行了定量评价。结果表明在MoO_4~(2-)浓度为2～5μg/mL时,测定相对误差不超过3.35%。     

Adsorption of carbamazepine from aqueous solutions on expanded graphite

Expanded graphite, which was prepared from natural graphite as a result of thermal treatment with acids, was used for the removal of the anticonvulsive preparation carbamazepine from aqueous solutions. The adsorption isotherm of carbamazepine was adequately described by the Langmuir, Temkin, and Freundlich equations. The adsorption of carbamazepine under dynamic conditions was studied.     

Adsorption of tetracycline from aqueous solutions on expanded graphite

Thermally expanded graphite, which was obtained from natural graphite as a result of thermal treatment with acids, was used for the removal of tetracycline as a typical antibiotic. The isotherm of adsorption of tetracycline was satisfactorily described by the Langmuir, Temkin, and Freundlich equations. The kinetics of absorption of tetracycline on thermally expanded graphite was studied.     

Fabrication of polyethylene/graphite nanocomposite from modified expanded graphite

A novel process was employed to fabricate a polymer/expanded graphite nanocomposite by modifying the conducting filler expanded graphite (EG) with unsaturated polyester resin (UPR). The modified expanded graphite (MEG) was prepared from EG in which the graphite nanosheets, already present in EG, were wrapped and isolated by the UPR during processing. The as‐prepared MEG was reduced to powder form to improve its dispersion in the matrix. MEG powders were embedded into a high‐density polyethylene (HDPE) matrix via melt‐extrusion in a single‐screw extruder to prepare the conducting composite. The as‐prepared HDPE/EG conducting composite exhibited a low percolation threshold of ～5.7 wt% due to the high aspect ratio of graphite nanosheets. Mechanical properties such as the tensile and impact strength were also studied. Scanning electron microscopy was used to characterize the microstructure of EG, MEG powder and the resulting nanocomposites. Copyright © 2006 Society of Chemical Industry     

Adsorption of diclofenac sodium from aqueous solutions on expanded graphite

The adsorption of a diclofenac sodium medicine from aqueous solutions of different concentrations on expanded graphite, which was obtained as a result of the thermal treatment of graphite with perchloric acid, was studied. The recovery of diclofenac sodium from aqueous solution on expanded graphite was as high as 98–99%.     

固体超强酸ZrO_2-SO_4~(2-)催化合成乙酸糠酯

以固体超强酸ZrO2 SO2 -4为催化剂合成了乙酸糠酯。得到了适宜的催化剂制备条件及反应条件 :以氨水沉淀ZrOCl2 ·8H2 O溶液 ,以 0 75mol/L硫酸溶液浸渍ZrO2 ,并于 60 0℃下焙烧 4h。 0 2 5mol乙酸、0 2 5mol糠醇和 80ml甲苯混合后加入 4 g催化剂 ,产品收率可达 92 %。催化剂可重复利用 6次