氯化EVA/二氯乙烷溶液体系真空脱溶剂的传质模型研究

在脱溶剂初期 ,溶剂过饱和度是影响氯化EVA/二氯乙烷溶液体系脱溶剂速率的重要参数 ;在脱溶剂后期 ,还应通过高效率的表面更新来强化脱溶剂。该体系的真空脱溶剂传质模型可用气泡成核控制的起泡脱溶剂数学模型描述 ,传质速率方程可表示为r =KLa(C -Ce) n,其中 :n =2 5 .16 - 10 9.80S +179.5 2S2 -96 .87S3 ,KLa =4 0 .76 - 2 0 1.16S +319.6 2S2 - 16 2 .94 3     

纤维素溶液在PF／DMSO溶剂体系流变性能的研究

研究了棉浆和木浆溶解于PF／DMSO溶剂体系所得溶液的流变性能,如纤维素含量、温度的改变对非牛顿指数、结构粘度、零切粘度等流变参数的影响。两种溶液的粘流活化能均高于粘胶溶液,棉浆的反应性能优于木浆。     

烃类溶剂透过HDPE／MPA层状容器的传质模型

烃类溶剂透过ＨＤＰＥ／ＭＰＡ层状聚合物共混物的传质过程符合溶解－扩散模型Ｄ／Ｄ０＝ａ１ｅｂ１／φ。烃类溶剂渗透量Ｊ随温度Ｔ的变化关系为：Ｊ＝ａ２ｅｂ２Ｔ。渗透量Ｊ随时间ｔ的变化初始数天为指数关系，其后符合线性关系；ＭＰＡ的体积分数φ为定值时，温度升高，Ｄ／Ｄ０值下降。     

氨吹脱过程的传质模型

试验设计了一种新型的氨吹脱反应器,采用雾化喷头代替了传统的填料,废水经过加压雾化后与上升的气流逆向接触,通过增加接触面积达到提高去除率的目的.对气液传质过程作了合理假设,运用微分学等数学方法,得到氨吹脱过程的传质模型,讨论了模型中参数的影响因素,说明了去除率η随着pH和温度的提高、运行时间的延长、鼓风量的增大而增大,通过试验验证了使用这种新型的氨吹脱反应器来处理含高浓度氨氮的废水,在合适条件下,氨去除率高于85%.     

EVA/CPE共混体系的反气相色谱研究

用反气相色谱（IGC）研究了乙烯-醋酸乙烯酯（EVA）/氯化聚乙烯（CPE）共混物的等温相分离过程，以该共混体系的相容性做出定性判断；用IGC测定了EVA，CPE及其共混物的溶度参数。     

碳酸钙填充EVA／再生PE体系的发泡效果

对几种不同规格的碳酸钙（分别为400目、800目和2500目重质碳酸钙）对EVA／再生PE体系的发泡效果进行了研究，通过对发泡曲线、发泡体体积膨胀率、表观密度和硬度的比较分析，对三种不同目数的碳酸钙在不同填充量时的发泡效果进行了评价。结果表明，三种规格碳酸钙的发泡有相似之处，尤其是都表现出了高填充（180份）和高发泡（发泡体积膨胀倍数≥6)的可行性。     

填料塔传质模型的研究——二维混合池随机模型

本文推导和提出了一个新的数学模型——二维混合池随机模型.它能用来模拟填料塔的液体流动和传质特性,以及计算塔中液、气两相浓度分布.该模型的主要特点是:(1)它通过调整混合池间轴向和径向的流动和混合,能很好地模拟填料塔复杂的液体流动状态;(2)模拟计算考虑了液体流动分布的随机性质.研究结果表明,填料塔塔径增大或填料层增高而产生的传质效率下降的原因主要是液体的非均匀流动、轴向混合的加剧和不完全的径向混合.     

二元溶剂体系中CrCl_3催化木糖制备糠醛的研究

对木糖在甲苯/水二元溶剂体系中直接转化制备糠醛进行研究。考察了6种氯化物CrCl3·6H2O,AlCl3·6H2O,FeCl3,CuCl2·2H2O,CoCl2·6H2O,ZnCl2的催化效果,结果表明:选用的金属氯化物均具有一定的催化效果,其中CrCl3·6H2O的催化效果明显优于其他氯化物。以CrCl3·6H2O为催化剂,系统研究反应温度、反应时间、催化剂浓度、木糖质量分数、NaCl添加量对糠醛产率的影响,反应的最佳条件为:反应温度140℃、反应时间60 min,CrCl3·6H2O浓度0.1 mol/L,木糖及NaCl的质量分数分别为4%和15%。在该条件下,糠醛产率为52.55%。     

CA膜分离MeOH/MTBE混合体系的渗透汽化传质模型

根据UNIQUAC模型和溶解扩散模型,建立了CA膜分离MeOH/MTBE混合体系的渗透汽化(PV)传质模型,模型计算值与试验值吻合良好.采用UNIQUAC模型关联MeOH-MTBE混合液的汽液平衡数据以及MeOH和MTBE在醋酸纤维素膜内的等温吸着数据,得到UNIQUAC相互作用参数,预测混合物组分在膜内的溶解度.用溶液吸着溶胀试验测得了MeOH/MTBE混合物在CA膜内的扩散系数,由6参数模型回归得到各个相互作用参数.     

1,2-二氯乙烷作共沸剂去除乙酸溶液中水分的研究

采用1,2-二氯乙烷作为共沸剂,对乙酸废水进行乙酸回收。利用1,2-二氯乙烷和水的共沸点和乙酸沸点的差距以及1,2-二氯乙烷在水中溶解度低的优点,采取共沸蒸馏除水。乙酸溶液回收之后,含水体积分数由原来50%左右降至0.1%以下,并且乙酸回收率达到95%以上。     

万能胶中1,2-二氯乙烷的挥发性能及风险研究

鉴于1,2-二氯乙烷的高毒性及在溶剂型胶粘剂中已普遍使用,为了考察工作场所的安全性,以万能胶为代表,在1m3气候箱内分别从两个方面考察了贴面板中1,2-二氯乙烷的挥发性能:在万能胶浓度相同的前提下,1,2-二氯乙烷的挥发浓度与万能胶涂布量的关系;万能胶中1,2-二氯乙烷的挥发速率与1,2-二氯乙烷在万能胶中的浓度和挥发时间的关系。研究结果表明:对单面板而言,短时间内低1,2-二氯乙烷浓度的万能胶中1,2-二氯乙烷的挥发速率较高,并随时间的延长挥发速率有所减弱;而在高1,2-二氯乙烷浓度的万能胶中,短时间内1,2-二氯乙烷的挥发速率则随时间的延长而加快;1,2-二氯乙烷的挥发浓度与施胶量呈正比关系。对夹合板而言,1,2-二氯乙烷的挥发速率较均匀,若要使1,2-二氯乙烷完全挥发,则需要较长的时间;使用含1,2-二氯乙烷的万能胶存在一定的安全风险。     

作业场所溶剂型胶粘剂中1,2-二氯乙烷使用情况风险预警

鉴于1,2-二氯乙烷的高毒性,为了考察溶剂型胶粘剂中1,2-二氯乙烷的使用风险,对鞋类、箱包类和家具类等作业场所溶剂型胶粘剂(含1,2-二氯乙烷)的使用情况进行了调研。结果表明:有9家车间的1,2-二氯乙烷挥发浓度在22～98mg/m3之间,高于职业接触限值(15mg/m3);鞋类、箱包类和家具类等制造企业中存在一定的1,2-二氯乙烷使用风险。     

Kinetics of facilitated proton transfer by hydrophobic aromatic amines across the water/1,2-dichloroethane interface

The kinetics of proton transfer facilitated by 4-octylaniline, 4-dodecylaniline and 4-hexadecylaniline across the water/1,2-dichloroethane interface has been investigated by cyclic voltammetry and ac impedance. It was found that their electrochemical behaviour is very similar and the three amines assist proton transfer from the aqueous to the organic phase. The formal Gibbs energy of proton transfer and the formal rate constant were evaluated. It is concluded that interfacial organisation of these molecules is an important factor in the kinetics of facilitated proton transfer and that the aromatic ring is able to penetrate the interface whilst the long hydrophobic chain contributes to the stability of the amine in the organic phase.     

Comparative analysis of the transfer of alkaline and alkaline-earth cations across the water/1,2-dichloroethane interface

The transfer of alkaline and alkaline-earth cations across the water/1,2-dichloroethane interface in presence of 1,10-phenanthroline (phen) in the organic phase was studied using cyclic voltammetry in a concentration range wide enough to cover the following experimental conditions: C_M2+(w) C_phen(o) and C_phen(o) C_M2+(w).

The results obtained (when C_M2+(w) C_phen(o)) were compared with the theoretical voltammetric criteria reported by Homolka1l] for facilitated transfer. It appears that the transfer of all these cations occurs via a facilitated mechanism. The stoichiometry of all complexes formed in the organic phase is also reported. The stability constants for Ca²⁺-phen and Sr²⁺-phen complexes were estimated and compared with the tendency observed in the transfer potentials of these cations.     

Ag transfer across the water/1,2-dichloroethane interface facilitated by complex formation with tetraphenylborate derivatives

The assisted transfer of silver ion, Ag⁺, by complexation of Ag⁺ with the tetrakis(4-chlorophenyl)borate (TPBCl⁻) anion was studied at the interface between two immiscible electrolyte solutions (ITIES).The elucidation of the interfacial mechanisms employed the cyclic voltammetry technique applied to macro and micro liquid/liquid interfaces. This procedure allowed to identify Ag⁺ as the species which is transferred at the liquid/liquid interface and also the formation of an 1:2 metal:ligand complex when TPBCl⁻ is in excess.The value for the formal transfer potential of silver(I) from aqueous to 1,2-dichloroethane was evaluated and the association constant for the [Ag(TPBCl)₂]⁻ complex was determined.     

三基药真空驱溶工艺探索

现有三基药驱溶过程通过热风驱除固体颗粒内的有机溶剂,工艺时间较长。采用真空驱溶方法探索了驱溶时间、真空度、湿度等对三基药总挥发分的影响。结果表明,通过真空驱溶工艺获得的样品总挥值与国军标的要求差距较大,无法达到快速驱除三基药内有机溶剂的目的,此工艺方法不适用于三基药的驱溶过程。     

Kinetics of Pd/alumina catalysed 1,2-dichloroethane gas-phase oxidation

The complete catalytic oxidation of 1,2-dichloroethane (DCE) over palladium supported on alumina was evaluated. The effect of temperature, inlet DCE concentration, and the space time on the reaction rate and selectivity was examined with the aim of better understanding of the reaction pathway. DCE oxidation reactions were carried out in a conventional fixed-bed reactor at atmospheric pressure under conditions of lean DCE concentration in air. The outlet composition was analysed by a gas chromatograph equipped with an electron capture detector (ECD) and a thermal conductivity detector (TCD). The reaction scheme resulted in a first dehydrochlorination step of DCE, leading to the formation of vinyl chloride (VC), followed by direct oxidation of VC to CO and CO₂. CO is finally oxidized to CO₂. The developed kinetic model provided an accurate correlation of the experimental data, determined by a non-linear least-squares regression.     

Effect of N(4)-substituent groups on transfer of 2-benzoylpyridine thiosemicarbazone derivates at the water/1,2-dichloroethane interface

Dependent on the pH of the aqueous phase, the transfer of protonated forms of 2-benzoylpyridine N(4)-phenyl thiosemicarbazone (BPPT) (which has antimicrobial, antifungal and anticytotoxic activities) and 2-benzoylpyridine N(4)-ethyl thiosemicarbazone (BPET) across water/1,2-dichloroethane (1,2-DCE) interface has been studied by cyclic voltammetry. The protonation constants of the ligands ( and ) were determined by spectrophotometry. The standard partition coefficients () and the standard Gibbs energies of ionic (cationic) species of ligands () were calculated from the standard transfer potentials (). The standard Gibbs energies of their transfer () and partition coefficients of neutral species (log P_N) were determined by shake-flask method. These thermodynamic parameters were evaluated as a quantitative and qualitative measure of the lipophilicities of two compounds. The differences between the partition coefficients of cationic and neutral form of compounds [diff(log PI⁺−N)] were interpreted by results obtained from voltammetric data. Effect of N(4)-phenyl and ethyl groups for transfer of 2-benzoylpyridine thiosemicarbazone derivatives at macro-liquid/liquid interface was investigated. The antimicrobial activity of BPET was tested against four types of bacteria and found to be active against Staphlylococcus aureus.