海绵钯表面CO、O2、CH4的吸附特性

在300K和0～13.3 kPa压力范围内,测量了海绵钯表面对CO、o2、CH4的吸附等温线.结果表明:钯表面对CO的吸附量先随压力的升高而增加,之后呈现饱和吸附状态;对O2的吸附至少可以分3个区间,在0～100 Pa压力区间,吸附量随压力升高快速增加,此后直至4kPa的区间内,吸附量随压力升高较缓慢增加,但当压力高于4kPa时,吸附量随压力的升高而增加又变得较为显著:CH4的吸附量相对较小,并持续随压力升高而缓慢增加.在整个压力测量区间,CO、CH4的吸附等温线符合兰缪尔模型,而O2的吸附等温线只在压力小于1.33 kPa的区间才符合.     

温度对油酸钠在一水硬铝石表面的吸附量的影响

通过吸附量的测定、热力学分析及单矿物浮选试验,揭示温度对油酸钠在一水硬铝石表面的吸附量及其浮选的影响。结果表明:在15℃时,油酸钠在一水硬铝石表面的吸附等温线为L-S型吸附曲线;在32℃时,其为L型吸附曲线。初始浓度在2 mmol/L以下时,油酸钠在一水硬铝石表面为单分子层吸附,吸附热约为-89.31k J/mol,属化学吸附,32℃时的吸附量高于15℃时的,ΘΔ15℃GΘ2Δ3℃G,温度的降低导致油酸钠的吸附量减少,主要是油酸钠的溶解度降低所致;低温下,增加矿浆温度比增大捕收剂用量能更有效地提高油酸钠吸附量及浮选回收率。     

季铵型阳离子捕收剂在一水硬铝石和高岭石表面的吸附机理

研究十二烷基三甲基氯化铵（DTAC）和十六烷基三甲基氯化铵（CTAC）对一水硬铝石和高岭石的浮选行为。通过残余浓度法测定吸附等温线,荧光探针法和Zeta电位测试方法研究季铵型阳离子捕收剂在矿物表面的吸附机理。浮选结果表明：将DTAC和CTAC作为捕收剂,一水硬铝石的浮选回收率随着pH的增大而增加,而高岭石的浮选回收率随着pH的增大反而下降。当捕收剂的碳链增长时,矿物浮选回收率提高,但高岭石的增加幅度小于一水硬铝石的。在低浓度范围内,阳离子表面活性剂通过静电作用吸附在一水硬铝石表面,而对于高岭石,还存在离子交换作用。当浓度增大时,阳离子表面活性剂通过碳链间疏水缔合作用在两种矿物表面进一步吸附。矿物表面微极性研究表明：CTAC的疏水性比DTAC强,相同溶液浓度下CTAC在一水硬铝石表面能形成比在高岭石表面更大的胶团,这也说明阳离子表面活性剂碳链的增长对一水硬铝石吸附的影响要大,与浮选结果相吻合。     

氧分子在黄铁矿和方铅矿表面的吸附

采用密度泛函理论对氧分子在黄铁矿和方铅矿表面的吸附进行研究。计算结果表明:黄铁矿和方铅矿表面经历了较小的弛豫;氧分子在黄铁矿和方铅矿表面都呈解离吸附状态,且在黄铁矿表面的吸附能远低于在方铅矿表面的吸附能;在黄铁矿表面上,氧原子分别与铁原子和硫原子键合,电子由铁原子和硫原子转移到氧原子上,主要由硫的3p态、氧的2p态和铁的3d态参与反应,铁与氧之间形成d→p反馈键,而在方铅矿表面上,氧原子只与硫原子键合,主要由硫的3p态、氧的2p态和铅的6p态参与反应,未形成反馈键;氧吸附后黄铁矿表面产生键合的铁原子和氧原子都产生自旋现象,而方铅矿表面原子及吸附的氧原子仍然是低自旋态的。     

3-己基-4-氨基-1,2,4-三唑-5-硫酮在黄铜矿表面的吸附动力学与热力学

合成了一种新型的三唑硫酮类表面活性剂—3-己基-4-氨基-1,2,4-三唑-5-硫酮(HATT),通过红外光谱和核磁共振氢谱及磁谱对其结构进行了表征,研究其在黄铜矿表面的吸附动力学和热力学。结果表明:黄铜矿吸附HATT优选的p H值为4~8,吸附量随着温度的升高而增大;吸附过程符合准二级动力学方程,吸附活化能为13.06 k J/mol;HATT在黄铜矿表面的吸附等温线符合Langmuir模型,吸附焓变ΔH为71.52 k J/mol,熵变ΔS为348.7 J/(mol·K),吸附自由能变ΔG为-28.95 k J/mol(298K)。HATT可能以单分子层化学吸附于黄铜矿表面,吸附为自发的吸热过程。FTIR光谱分析进一步证实HATT以化学方式吸附在黄铜矿的表面。浮选试验结果也表明,HATT是黄铜矿的优良捕收剂。     

聚丙烯酸钠在硅酸二钙-铝酸钠溶液界面的吸附行为

测定了80℃时2CaO.SiO2（C2S）在铝酸钠溶液中吸附聚丙烯酸钠（AY）的吸附量等温线。结果表明：AY在C2S表面的吸附类型为饱和吸附,吸附行为属＂L＂型,符合Langmuir方程单分子层吸附模型。结合C2S的比表面积可求出AY饱和吸附时表面覆盖度为1.06mol/μm2。同时,运用Gibbs公式处理C2S在固-液界面的吸附结果,研究吸附膜的表面压力和分子面积的关系曲线,并讨论因吸附引起的固-液界面能变化规律以及曲线与吸附类型的关系。     

K2L-SAMs对碳钢在饱和CO2油田水中的缓蚀行为与量子化学研究

利用邻氧乙酸苯甲醛缩对氨基苯磺酸钾盐席夫碱(K2L)缓蚀剂在20#碳钢表面制备自组装单分子膜(SAMs),并通过电化学方法研究缓蚀剂自组装膜的最佳组装时间;采用电化学测试技术和表面分析技术研究K2L-SAMs对碳钢在饱和CO2油田水介质中的缓蚀行为;采用密度泛函理论分析缓蚀剂分子的前线轨道、Mulliken电荷和分子静电势。结果表明:缓蚀剂在碳钢表面自组装3 h后,可以形成稳定、致密的缓蚀膜;在碳钢表面形成的K2L-SAMs能有效抑制碳钢的阴极还原过程,最高缓蚀效率达87.55%;K2L的吸附行为符合Langmuir吸附等温式,吸附机理为典型的化学吸附。量子化学计算结果表明:羧基是K2L分子的主要吸附活性区域,能与碳钢表面铁原子作用形成稳定的配位键。     

强酸性阳离子交换树脂对铅的吸附行为及机理

通过静态吸附实验,研究了Pb2 在001×7强酸性阳离子交换树脂上的吸附行为,并从热力学和动力学方面对吸附过程进行了分析,用红外光谱的方法探讨了001×7树脂吸附Pb2 的机理.结果表明在所研究的浓度范围内,Pb2 在001×7树脂上的吸附平衡数据符合Freundlich等温吸附方程,吸附为自发进行的放热过程;液膜扩散为Pb2 在001×7树脂上吸附速率的主要控制步骤,随着振荡频率的增加,吸附速率会逐渐增大;最佳的吸附pH在4左右,用3 mol/L的硝酸对饱和树脂进行洗脱再生,洗脱率可达98%以上;298 K温度下树脂的静态饱和吸附容量为414 mg/g(湿树脂).     

缓蚀剂钼酸盐插层水滑石对Cl- 吸附行为的研究

以缓蚀剂钼酸盐插层水滑石(HT-MoO42-)为吸附剂,对NaCl 溶液中的Cl-进行吸附,探讨了吸附时间、温度和Cl-初始浓度等因素对吸附的影响。测定了HT-MoO42-吸附Cl-前后的元素组成变化,测定了吸附等温线和吸附动力学曲线。结果表明,该吸附反应为介孔单分子层与多分子层吸附相结合,在70 h 内达到吸附平衡,吸附量随Cl-初始浓度、温度的增加而增大,吸附过程遵循Lagergren 二级反应动力学过程,相关系数R2 为0.9981。     

螺旋藻粉生物质回收稀土元素Yb(Ⅲ):吸附等温线、动力学和热力学

研究以螺旋藻粉作为吸附剂从废水溶液中回收Yb(Ⅲ)的吸附特性和机理。利用SEM和XPS对吸附剂的表面结构以及元素价态进行分析,探究螺旋藻粉对Yb(Ⅲ)的吸附机理;通过吸附等温线、动力学和热力学模型分析螺旋藻粉对Yb(Ⅲ)的吸附特性。Langmuir模型表明,当温度为318K时,螺旋藻粉对Yb(Ⅲ)的最大吸附量为72.46mg/g。动力学实验结果表明,拟二级动力学模型能较好地模拟螺旋藻粉对Yb(Ⅲ)的吸附过程,化学吸附为螺旋藻粉吸附Yb(Ⅲ)的控速步骤。吸附-脱附循环实验结果表明,螺旋藻粉具有良好的稳定性和重复使用性,是一种高效且经济的Yb(Ⅲ)回收材料。     

Electrochemical noise resistance evaluation of 304L SS in nitric acid and simulated nuclear high level waste

The paper focuses on corrosion monitoring of 304L stainless steel (SS) (solution annealed, sensitised) in nitric acid (4, 8 and 12M) at 298 and 323 K electrolyte temperatures, and simulated high level waste (HLW, 323 K), using electrochemical noise (EN) measurements. Double loop electrochemical potentiokinetic reactivation test was conducted to assess the degree of sensitisation. Electrochemical noise records revealed passivation process during the monitoring period, under all conditions studied, except for the sensitised specimen in 4M nitric acid (323 K), which showed localised attack. The results showed an inverse relation between EN resistance and corrosion activity. An increase in nitric acid concentration resulted in an increase in corrosion activity, while increasing the electrolyte temperature increased the corrosion activity marginally. A profound increase in corrosion activity occurred for the sensitised specimen in nitric acid when compared to the solution annealed specimen, but the increase was marginal in simulated HLW. The results are detailed in the paper.     

土酸溶液中苯扎溴铵对碳钢的缓蚀作用研究

采用失重法和电化学极化曲线研究了不同温度下苯扎溴铵对5%的土酸溶液中碳钢的缓蚀作用。实验结果表明,苯扎溴铵在碳钢表面产生单分子层吸附,并且满足Langmuir吸附规律;吸附过程为放热过程,随着温度的升高,吸附能力减弱,缓蚀效率下降;苯扎溴铵为混合型缓蚀剂。     

Corrosion inhibition of mild steel in acidic solution by some oxo-triazole derivatives

The oxo-triazole derivative (DTP) was synthesized and its inhibiting action on the corrosion of mild steel in sulphuric acid was investigated by means of weight loss, potentiodynamic polarization, EIS and SEM. The results revealed that DTP was an excellent inhibitor and the inhibition efficiencies obtained from weight loss experiment and electrochemical experiment were in good agreement. Potentiodynamic polarization studies clearly revealed that DTP acted essentially as the mixed-type inhibitor. Thermodynamic and kinetic parameters were obtained from weight loss of the different experimental temperatures, which suggested that at different temperatures (298–333 K) the adsorption of DTP on metal surface obeyed Langmuir adsorption isotherm model.     

盐酸溶液中阳离子Gemini表面活性剂在碳钢表面的吸附与缓蚀性能研究

 合成并用元素分析和核磁共振(1H-NMR)表征了阳离子Gemini表面活性剂1,2-双亚甲基-双(十烷基二甲基溴化铵)和1,2-双亚甲基-双(十二烷基二甲基溴化铵)(分别简写为10-2-10和12-2-12)，并用失重法研究了1M盐酸溶液中该类表面活性剂在碳钢表面的吸附行为及其缓蚀性能.实验结果表明，其缓蚀机理为表面活性剂在钢铁表面的吸附形成单分子膜，从而阻碍了盐酸对钢铁的侵蚀，其缓蚀效率随着表面活性剂浓度的增加而增加，当表面活性剂浓度接近其临界胶束浓度时达到最大，理论计算表明，在研究的浓度范围内，盐酸溶液中该类Gemini表面活性剂在碳钢表面的吸附行为符合Langmuir吸附等温式.      

Protection of 6061 Al-15%<Subscript>(v)</Subscript> SiC<Subscript>(P)</Subscript> composite from corrosion by a biopolymer and surface morphology studies

The protective action of biopolymer starch on 6061 Al-15%_(v) SiC_(P) composite in 0.25 M hydrochloric acid was studied by potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) techniques with temperature ranging from 303 to 323 K. The concentrations of starch used were in the range of 0.1 to 0.8 g L^–1. The surface morphology studies were carried out using Scanning Electron Microscope, Energy Dispersive X-ray analysis, Atomic Force Microscope and X-ray Diffraction analysis techniques. Suitable mechanism was proposed for the corrosion and inhibition process. Results indicated increase in the efficiency of the inhibitor with its increase in the concentration and with temperature. Maximum inhibition efficiency of 84% was observed at 323 K for 0.8 g L^–1. Starch acted as a mixed inhibitor. Kinetic and thermodynamic studies showed that starch underwent chemical adsorption and obeyed Langmuir adsorption isotherm. Surface morphology studies confirmed the adsorption of inhibitor on the surface of metal matrix composite. Results obtained by potentiodynamic polarization method and electrochemical impedance spectroscopy method were in good agreement with one another.     

Kinetic modeling of adsorption of vanadium and iron from acid solution through ion exchange resins

This study assessed the adsorption process and the reaction kinetics involved in the selective recovery of vanadium from an acid solution containing iron as an impurity. Four commercial resins were studied: Lewatit® MonoPlus TP 209 XL, Lewatit® TP 207, Dowex? M4195 (chelating resin) and Lewatit® MonoPlus S 200 H (strong cationic exchange resin). To investigate the effect of time on the adsorption process, batch experiments were carried out using the following initial conditions: pH 2.0, 298 K, and a proportion of 1 g of resin to 50 mL of solution. The variation of pH over time was analyzed. Chelating resin released less H⁺ ions as the adsorption occurred, resulting in a lower drop of pH when compared to S 200 H resin. Ion adsorption by the resins was also evaluated through FT-IR and SEM?EDS before and after the experiments. Among the evaluated kinetic models (pseudo-first order, pseudo-second order, Elovich and intraparticle diffusion models), the pseudo-second order model best fits the experimental data of the adsorption of vanadium and iron by all of the four resins. M4195 resin showed the highest recovery of vanadium and the lowest adsorption of iron. Kinetic data, which are fundamental to industrial processes applications, are provided.     

颗粒活性炭对乳酸钠的吸附及其特性

将颗粒活性炭碾磨处理后用于吸附乳酸钠,并采用单因子实验考察溶液pH值、温度对活性炭吸附量的影响。对吸附等温线的分析表明,碾磨时间不同的活性炭对乳酸钠的吸附行为均可用Freundlich方程描述,对比吸附常数和固相-水分配系数发现,碾磨30 min后活性炭的吸附能力最强;碾磨活性炭吸附乳酸钠的最佳pH为7.0,且吸附量受温度的影响不大。     

Potential-pH diagrams of Cr-H2O system at elevated temperatures

The potential—pH diagrams of the Cr-H₂O system at temperatures of 298, 323, 373 and 423 K were established through thermodynamic calculation with coupling of experimental results. The potential—pH diagram at 298 K agrees well with the previously reported results. Based on the potential—pH diagrams of the Cr-H₂O and Fe-H₂O systems, IR spectra and XRD pattern, the existence forms of iron in the potassium chromate were analyzed, and the methods of iron removal were investigated. The results show that the existence forms of iron in the potassium chromate are potassium ferrate. These results are instructive and helpful to the hydrometallurgical processing of chromite ore.     

氨基磺酸溶液中苯甲醛对锌的缓蚀作用及吸附热力学研究

在5％氨基磺酸溶液体系中,采用失重法考察不同温度下不同浓度的苯甲醛对锌的缓蚀作用;并对氨基磺酸介质中苯甲醛在锌表面吸附热力学进行了研究。当苯甲醛在低浓度时,随浓度增大,缓蚀作用增强;当其浓度达到一定值后,缓蚀作用基本保持不变。实验结果表明,苯甲醛在锌表面产生饱和单分子层吸附,并且满足Langmuir吸附规律。△G^0〈0,表明苯甲醛在锌表面的吸附是自发进行的。随着温度升高,△G^0增大导致缓蚀剂的吸附能力下降。△H^0〈0,表明在所研究的温度范围内吸附过程是放热过程。△S^0〉0说明苯甲醛吸附于锌表面,使锌表面的水分被挤走,体系进入更为无序状态。     

Inhibition of pure iron by new synthesized tripyrazole derivatives in HCl solution

Inhibitory effect of some new synthesized tripyrazole compounds on corrosion of pure iron in 1 M HCl solution has been studied using weight-loss measurements and various electrochemical techniques polarization and impedance spectroscopy methods. The inhibiting action is more pronounced with N,N,N-tris[(3,5-dimethyl-1H-pyrazol-1-yl)methyl] amine (P1), and its inhibition efficiency increases with its concentration and attains the maximum value of 94% at the 2.5 × 10⁻⁴ M. The effect of temperature on the corrosion behaviour of iron was studied in the range from 298 to 353 K with and without P1 at 2.5 × 10⁻⁴ M. We note a good agreement between gravimetric and electrochemical methods potentiodynamic polarization and impedance spectroscopy (EIS). Polarization measurements show also that the compound acts mixed inhibitor. The catholic curves indicate that the reduction of proton at the pure iron surface happens within a pure activating mechanism. EIS measurements show the increase of the transfer resistance with the inhibitor concentration. The presence of the N,N,N-tris[(3,5-dimethyl-1H-pyrazol-1-yl)methyl] amine increases the inhibition efficiency and not caused a drastic change in its adsorption mechanism. The adsorption of P1 on the surface of iron in 1 M HCl obeys a Langmuir isotherm adsorption.