丁烯异构化L-H机理复杂反应动力学

用玻璃外循环无梯度反应器研究了丁烯异构化L-H机理复杂反应动力学. 用正交设计法估计了动力学方程中的参数. 色谱法测定了丁烯吸附热, 并研究了异构化生成反-2-丁烯及顺-2-丁烯的动力学方程.     

在Fe-Zn-Mg-Cr尖晶石结构催化剂上丁烯-2氧化动力学

用玻璃外循环无梯度反应器研究了在Fe-Zn-Mg-Cr尖晶石结构催化剂上丁烯-2氧化脱氢动力学。丁烯-2氧化脱氢动力学服从三步骤Redox机理。用脉冲法研究了催化剂用丁烯-2还原及还原催化剂用氧再氧化步骤。用脉冲法测定了丁烯-2吸附热。丁烯-2及丁二烯深度氧化动力学服从经验速度方程。用正交设计法估计了动力学方程的参数。丁烯-2氧化脱氢速度比丁烯-1要快。     

在 La-Cr-Fe 钙钛矿型催化剂上丁烷、反-2-丁烯及顺-2-丁烯深度氧化动力学

在La-Cr-Fe 钙钛矿型催化剂上用玻璃外循环无梯度反应器研究了丁烷、反-2-丁烯及顺-2-丁烯深度氧化动力学。丁烷、反-2-丁烯及顺-2-丁烯深度氧化动力学服从L-H机理模型。用正交设计法估计了动力学方程中的参数值。丁烷、反-2-丁烯及顺-2-丁烯深度氧化的L-H 机理模型为脉冲实验鉴别。用脉冲色谱法测定了“2-丁烯”及O_2的吸附热。丁烷、反-2-丁烯及顺-2-丁烯深度氧化的CO_2生成速度用(7)式描述。     

热动力学对比进度法(Ⅲ)——2-Ⅰ型可逆反应的热动力学研究

本文建立了2-Ⅰ型可逆反应的热动力学对比进度方程和热动力学模型。用热导式自动热量计研究了一个2-Ⅰ型吸热反应体系,并对结果进行了讨论。     

2,3,4,9-四氢-9-羟基-1,10-蒽醌的合成及荧光猝灭法测定痕量砷

荧光动力学分析法常以罗丹明类、荧光素类、桑色素等作为指示物,用蒽醌作为指示物较少见。本文报道了以2,3,4,9-四氢-9-羟基-1,10-蒽醌(简称R)为指示物,荧光动力学分析法测定痕量砷的新方法。实验直接用硼酸代替三氯化铝加硫酸封环一步法制得1,4-二羟基-9,10-蒽醌,再经冰醋酸和     

二氢蒽醌用于荧光猝灭法测定痕量汞

荧光动力学分析法常以罗丹明类、荧光素类、桑色素等作为指示物,用蒽醌作为指示物较少见。本文报道了以2,3二-氢-9,10二-羟基-1,4蒽-醌(R)为指示物,荧光动力学分析法测定痕量汞的新方法。直接用硼酸代替三氯化铝加硫酸封环一步法制得1,4二-羟基-9,10蒽-醌,再经冰醋酸和锌粉还原     

N-乙烯吡咯烷酮/甲基丙烯酸-β-羟乙酯无规共聚物凝胶对蛋白质吸附机理的研究

用紫外分光光度法研究了牛血清白蛋白(BSA)在N-乙烯吡咯烷酮(NVP)/甲基丙烯酸-β-羟乙酯(HEMA)共聚物水凝胶上的吸附量.结果表明,BSA在凝胶上的吸附关系既可用Langmuir方程描述,又可用计量置换吸附Freundlich方程描述,且用Langmuir方程描述更为优越.研究了凝胶对BSA的吸附动力学行为,建立牛血清白蛋白的吸附动力学模型,发现用Bangharm方程对BSA吸附动力学曲线拟合程度较好,Bangharm方程可以较好地描述BSA在NVP/HEMA凝胶上的吸附动力学行为.     

在Fe-Zn-Mg催化剂上丁烯-1氧化脱氢制丁二烯动力学

用玻璃流动外循环反应器研究了Fe_4.9Zn_0.9Mg_0.1(原子比)催化剂上丁烯-1氧化脱氢动力学,丁烯-1氧化脱氢制丁二烯、丁烯-1及丁二烯深度氧化生成CO₂的动力学用双反应分子强吸附的L-H(LangmuirHinshelwood)机理方程描述。速度方程的参数用非线性最小二乘法估计,得丁二烯生成速度r_D和CO₂生成速度r_co2的动力学方程式。     

微量反应系统化学动力学教学实验的设计与应用

利用光纤光谱仪构建微量反应系统,并通过偶氮染料橙黄II在铁-亚硫酸钠-溶解氧体系中的脱色反应,分别用特征动力学方程法及初始速率法进行了脱色反应动力学分析。该实验体系能够实现简单、快速的均相溶液反应动力学实验,其数据处理方法较好地巩固和提升了对反应动力学理论课教学内容的学习。整个实验体系的设计与应用能够满足物理化学、大学化学、环境化学等相关课程中有关反应动力学的实验教学需求。     

耐热芴型环氧树脂的非等温固化动力学

合成了9,9’-二[4-(2,3环氧丙氧基)苯基]芴,并以4,4’-二氨基二苯砜胺为固化剂,用非等温DSC法研究了其固化动力学,用Flynn-Wall-Ozawa法和Friedman法确定了固化动力学参数,用动力学模拟推测了固化机理函数,并用TGA法对等温固化树脂的耐热性进行了表征。结果表明:双酚芴环氧固化反应的表观活化能约63.86 kJ/mol,扩散因子为3.80×104s-1,反应级数为1.57;固化反应为枝状成核的自催化反应;等温固化后的环氧树脂于400℃开始分解,700℃时残碳率为41.73%。     

Pd/C催化松脂分子间氢转移反应的集总动力学

以Pd/C为催化剂,在改进的动力学实验装置上研究了松脂分子间氢转移反应的集总动力学.在消除内、外扩散影响的条件下,在线跟踪反应产物并用气相色谱法测定反应体系组成随时间的变化,构造了Pd/C催化剂上松脂分子间氢转移集总反应网络,建立了包含单萜烯、枞酸型树脂酸、海松酸型树脂酸、对伞花烃、氢化单萜烯、脱氢枞酸、氢化枞酸型树脂酸和氢化海松酸型树脂酸等复杂反应体系的集总动力学模型,并估算了模型参数.松脂单萜烯和树脂酸的反应级数分别为1和2,并得到了松脂分子间氢转移中各反应过程的活化能.结果表明,所建动力学模型与实验数据吻合良好,并能预测反应在533 K下的集总组分浓度分布.Pd/C催化松脂分子间氢转移反应以脱氢反应为主,树脂酸的氢转移速率大于单萜烯的氢转移速率.     

Comparison of thermokinetic data obtained by isothermal, isoperibolic, adiabatic and temperature programmed measurements

In this paper isothermal, isoperibolic and adiabatic calorimeters and a Power-Compensating DSC are compared by determining kinetic data of a simple test reaction. First, the kinetic parameters were analyzed using a conventional isothermal method, based on the analytic determination of the course of reaction. Subsequently, the kinetic data of the performed reaction were determined for the different types of calorimeters by simultaneously evaluating several measurements with identical initial conditions but different temperature courses. The kinetic parameters obtained by the different calorimeters agree reasonable well, indicating the reliability of kinetic data derived from thermokinetic methods.The authors are thankful for the financial support by the Department of Education and Research of the Federal Republic of Germany (BMBF).     

Ni－海泡石催化剂催化苯气相加氢动力学

Ｎｉ－海泡石催化剂催化苯气相加氢动力学曹声春，杨礼嫦，彭峰，黄孟光（湖南大学化工系，长沙４１００８２）关键词镍，海泡石，负载型催化剂，苯，加氢，反应动力学Ｎｉ一海泡石催化剂通过制备工艺的优化，可使其苯加氢催化活性、选择性、热稳定性和抗毒性都优于现工业...     

孔雀石绿-H_2O_2体系动力学光度法测定微量溴化物

基于在NH3-NH4Cl介质中, Br-对H2O2氧化孔雀石绿的褪色反应有催化作用的特性, 建立了高灵敏度测定痕量溴化物的催化动力学光度分析法新体系. 讨论了酸度、试剂用量、温度、干扰离子等因素的影响. 研究了反应的最佳条件, 测定了一些动力学参数, 非催化反应和催化反应的的表观活化能分别为为52.85和19.53 kJ/mol. 方法的线性范围为0.10～1.2 μg/mL Br-, 检出限为 0.081 μg/mL. 方法用于水样中溴化物的测定, 结果与国标分析法所得结果相吻合.     

Cure kinetics of biphenyl epoxy‐phenol novolac resin system using triphenylphosphine as catalyst

The effects of the concentration of triphenylphosphine as a catalyst on the cure reaction of the biphenyl epoxy/phenol novolac resin system were studied. The kinetic study was carried out by means of the analysis of isothermal experiments using a differential scanning calorimeter. All kinetic parameters including the reaction orders, activation energy and kinetic rate constants were evaluated. To describe the cure reaction with the catalyst concentration, the normalized kinetic model was developed. The suggested kinetic model with a diffusion term was successfully able to describe and predict the cure reaction of epoxy resin compositions as functions of the catalyst content and temperature. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 713–720, 1999     

Cure Kinetics of Poly(acrylonitrile-butadiene-styrene) Modified Epoxy–Amine System

The cure kinetics of epoxy based on the diglycidyl ether of bisphenol A (DGEBA) modified with different amounts of poly(acrylonitrile-butadiene-styrene) (ABS) and cured with 4,4′-diaminodiphenylsulfone (DDS) was investigated by employing differential scanning calorimetry (DSC). The curing reaction was followed by using an isothermal approach over the temperature range 150–180°C. The amount of ABS in the blends was 3.6, 6.9, 10 and 12.9 wt%. Blending of ABS in the epoxy monomer did not change the reaction mechanism of the epoxy network formation, but the reaction rate seems to be decreased with the addition of the thermoplastic. A phenomenological kinetic model was used for kinetic analysis. Activation energies and kinetic parameters were determined by fitting the kinetic model with experimental data. Diffusion control was incorporated to describe the cure in the latter stages, predicting the cure kinetics over the whole range of conversion. The reaction rates for the epoxy blends were found to be lower than that of the neat epoxy. The reaction rates decreased when the ABS contents was increased, due to the dilution effect caused by the ABS on the epoxy/amine reaction mixture.     

Extraction of the contribution of kinetic profile for reaction of a chemical species in unknown matrices by standard addition method

A new and simple strategy is applied to resolve kinetic profile for the reaction of an analyte in unknown matrices, using standard addition method (SAM). The proposed method uses kinetic spectrophotometric data obtained by standard addition of analyte into unknown mixtures followed by the reaction of analyte with a proper reagent. The proposed method extracts kinetic profile for the reaction of an analyte by averaging the kinetic profiles obtained by subtraction of kinetic profiles after and before standard addition. The rate constant can be obtained using computational curve fitting. The performance of method was evaluated by using synthetic data as well as several experimental data sets. The proposed method can be applied to obtain kinetic profiles of the reactions in the presence of additive interference as well as multiplicative interferences. Hydroxylation reaction of diphenylcarbazide (DPCI) in the presence of diphenylcarbazone (DPCO) as a real system at various pHs was also studied by the present method. The rate constant and the order of the hydroxylation reaction were determined from extracted kinetic profiles.     

Artificial-intelligence-based interpretation of feature sensitivities of the Belousov-Zhabotinsky reaction

A new approach is presented for analyzing kinetic models of relaxation-type oscillatory systems on the basis of numerical data. Feature sensitivities of the length of the two kinetic states of the Belousov-Zhabotinsky (BZ) reaction with respect to the rate constants of the model are explained by means of a logic-based inference system. The main kinetic roles of the individual reaction steps on the relaxing components are revealed, and a consistent interpretation of the kinetic states is given by this process. Both the high and the low set of rate constants were studied. According to our analysis, the bromous acid-hypobromous acid reaction is an important Br^? producing step of the model, and in the case of the low set, the bromate-bromous acid reaction is not the rate-determining step of the bromous acid autocatalysis.     

聚乙二醇-聚苯乙烯接枝共聚物的合成及其接肽反应性能

本文应用环氧乙烷在羟乙基树脂上的开环聚合方法,合成了凝胶和大孔型聚乙二醇-聚苯乙烯接枝共聚物(简称PEG树脂)。对不同类型载体的接肽反应动力学性能研究表明,在PEG树脂载体上的反应速度是在氯甲基化树脂上的三倍,与在溶液中进行的接肽反应速率相当。此外,还对载体性能与树脂交联度、骨架结构之间的关系进行了初步探索。     

Scale-up of batch kinetic models

The scale-up of batch kinetic models was studied by examining the kinetic fitting results of batch esterification reactions completed in 75 mL and 5 L reactors. Different temperatures, amounts of catalysts, and amounts of initial starting reagents were used to completely characterize the reaction. A custom written Matlab toolbox called GUIPRO was used to fit first-principles kinetic models directly to in-line NIR and Raman spectroscopic data. Second-order kinetic models provided calibration-free estimates of kinetic and thermodynamic reaction parameters, time dependent concentration profiles, and pure component spectra of reagents and product. The estimated kinetic and thermodynamic parameters showed good agreement between small-scale and large-scale reactions. The accuracy of pure component spectra estimates was validated by comparison to collected NIR and Raman pure component spectra. The model estimated product concentrations were also validated by comparison to concentrations measured by off-line GC analysis. Based on the good agreement between kinetic and thermodynamic parameters and comparison between actual and estimated concentration and spectral profiles, it was concluded that the scale-up of batch kinetic models was successful.