毛细管内高分子溶液的浓度分布

采用连续自洽场理论分析了毛细管中发生凝胶化之前的聚合物溶液浓度分布的影响因素及其规律. 结果表明, 体系尺寸有限时, 改变聚合物链段、溶剂与壁面的相互作用参数之差, 聚合物溶液浓度分布会发生贫化/吸附转变; 临界作用参数与聚合物链长的倒数呈线性关系, 且拟合常数与体系尺寸、聚合物溶液平均体积分数有关; 聚合物分子量分布为多分散时, 分子量较低的组分更容易接近容器壁面, 分子量较大的组分则相反. 总之, 增加聚合物溶液浓度、链长, 选择优良溶剂, 减小体系尺寸等都会使浓度分布更加均匀.     

分子复合法制备新型聚合物驱油剂CMC/P(AM-DMDAAC)

通过具有互补结构的阴离子聚合物羧甲基纤维素(CMC)与阳离子聚合物聚(丙烯酰胺-二甲基二烯丙基氯化铵)[P(AM-DMDAAC)]间的聚电解质分子复合作用,制备了分子复合型CMC/P(AM-DMDAAC)新型驱油剂.电导率测定及紫外光谱分析结果表明,CMC与P(AM-DMDAAC)可以在水相通过库仑力形成均相聚电解质复合溶液.由于分子复合形成的独特超分子结构,复合溶液粘度显著增加,分别为组分聚合物溶液的5.2倍和9.0倍,在高温和高剪切环境中的粘度保持能力也明显优于其组分聚合物.     

成膜溶剂与氟化嵌段共聚物膜的表面富集行为

利用接触角、XPS、SFG、AFM等技术研究了环己酮、甲苯和三氟甲苯为成膜溶剂所得聚甲基丙烯酸甲酯-b-聚（甲基丙烯酸-2-全氟辛基乙酯）（PMMA—b—PFMA）嵌段共聚物膜的表面结构与性能．发现浇铸成膜时成膜溶剂对聚合物氟化组分向表面富集程度的影响相对较小,而旋涂成膜时溶剂的影响很大．不管以何种形式成膜,三氟甲苯溶剂最有利于氟化组分向表面富集,甲苯次之,环己酮最差．这一现象与溶剂的挥发速度无关．聚合物在溶液中的聚集结构、气／液界面结构是造成成膜方式对聚合物表面结构与性能产生巨大影响的主要原因．当聚合物在溶液中形成以PFMA为核、PMMA为冠的胶束结构时,在溶液固化过程中氟化组分向表面富集需要较长的时间,这时由于成膜方法直接影响溶液的固化速度,造成其对氟化组分向表面富集的程度影响很大．当聚合物在溶液中以单分子或松散聚集体存在,在溶液固化过程中氟化组分向表面富集的速度很快,这时成膜方法对氟化组分向表面富集的程度影响很小．以上结果无论对理论研究还是应用研究都具有重要意义．     

分别含有质子给体和质子受体的丙烯酸酯共聚物在溶液中的特殊相互作用研究

用粘度法和光散射法研究了分别具有质子给体 (Protondonor)和质子受体 (Protonacceptor)官能团的丙烯酸酯共聚物在溶液中的相互作用 .从粘度增长因子和聚合物在溶液中理想增比粘度的关系基础上提出了一个新的相互作用参数ka,研究了质子给体聚合物和质子受体聚合物在甲苯中的特殊相互作用 ,讨论了丙烯酸酯含量和酯烷基长度对组分间相互作用的影响 .结果表明 ,组分间的特殊相互作用随着丙烯酸长碳链酯含量和酯烷基长度的增加而增强 .光散射的结果表明ka 能够用于表征共混体系中的特殊相互作用     

含有不同功能基团的丙烯酸长链酯共聚物在溶液中的相互作用研究(Ⅰ)

合成了分别具有质子给体和质子受体官能团的丙烯酸正辛酯共聚物。由于在给体和受体聚合物上分别引入的羧酸基团（AA）和碱性基团（VP）,在溶液中进行共混复合时存在彼此间的相互作用而使共混体系表现出较高的比浓粘度。引入比浓粘度增长因子R,讨论了共混组分和溶剂体系等因素对聚合物分子链间相互作用的影响。结果表明,质子给体聚合物（PDP）和质子受体聚合物（PAP）的相互作用强度及等化学复合比与组分聚合物的分子链组成和溶剂性质有关。     

六种添加剂对烟丝挥发性与半挥发性成分含量的影响

分别配制1%(质量分数,下同)的柠檬酸、苹果酸、乳酸水溶液以及5%的(NH4)2HPO4、K2CO3、柠檬酸钾水溶液.分别取100.0g烟丝,均匀喷洒10.0mL上述水溶液,经平衡、实验室模拟烘丝、萃取后,进行气相色谱-质谱测定,分析烟丝中挥发性和半挥发性香味成分含量的变化.结果表明,喷洒柠檬酸和K2CO3水溶液可显著改变烟丝的化学成分含量.烟丝经K2CO3水溶液喷洒后,游离态的尼古丁含量大幅增加,醇类组分、巨豆三烯酮含量有所升高,酸类组分和酯类组分含量略有降低;而经柠檬酸水溶液喷洒后的烟丝的酸类、醇类和酯类组分含量升高,尼古丁含量下降.     

壳聚糖-丝心蛋白合金膜的研究(Ⅱ)──半互穿聚合物网络型膜对pH和离子的敏感性

研究了壳聚糖-丝心蛋白半互穿聚合物网络型膜对pH值和离子的敏感性,发现该膜在pH<3.3时溶胀度剧烈增加;在pH=2时,是否出现溶胀极大值与膜组分的含量及交联剂的含量有关;膜在不同pH值溶液中可交替溶胀和收缩,且这种溶胀-收缩行为重复可逆。同时,该膜在不同离子溶液中的溶胀度亦不同;在相同离子强度的溶液中,此膜在3价离子中的溶胀度最大。     

纸张上光油关键物质的成分分析

利用色相色谱／质谱联用技术，傅立叶红外及裂解－气相色谱／质谱联用技术，对印刷用上光油的关键成分进行了分析，共鉴定出７种挥发性组分，２种高分子聚合物。     

毛细管顶空色谱测定共聚醚的链节比

顶空气相色谱分析法是对液体或固体中挥发组分进行分析的一种测定方法。这一方法近年来在食品、药物以及环境分析中得到广泛应用。这一方法对分析聚合物中可挥发性组分有特殊的优点。它可以免去对样品冗长的预处理,以及高沸点物质对色谱系统的污染。静态顶空色谱法早已应用于聚合物中挥发组分的分析,但尚未见到测定聚醚链节比的报道。本文把顶空分析技术和毛细管色谱技术结合,通过测聚醚中的单体量推算出聚醚链节比。     

冠心苏合丸中挥发性组分的分析及主成分冰片的测定

采用同时蒸馏-萃取法提取冠心苏合丸中的挥发性组分,测得两种冠心苏合丸中的挥发性组分含量分别为14％和9．8％。利用GC-MS方法对两种冠心苏合丸所得的挥发性组分进行分析,通过检索NIST98谱图库,并结合标准谱图库和有关文献,从冠心苏合丸的挥发性组分中分别确定出14、19种化学成分,分别占挥发性组分总检出量的97．24％和98．76％。用峰面积归一化法,得出各化学成分在挥发性组分中的相对百分含量。主要挥发性组分是冰片。并采用气相色谱法对冠心苏合丸中冰片的含量进行了测定冰片质量浓度在1．0～5、0mg／mL范围内成良好的线性关系,冰片的平均回收率为98％～106％。     

Prediction of infinite dilution solvent activity coefficient in rubbery polymer solutions using Engaged Species Induced Clustering (ENSIC) model

It is extremely important to predict infinite dilution solvent activity coefficients in rubbery polymers in design and operation of polymer‐related processes. Many models have been developed to predict the activity coefficients. However, the accuracies of these models are not satisfactory. This article advances a method for predicting the infinite solvent dilution activity coefficients in the rubbery polymers, using the Engaged Species Induced Clustering (ENSIC) model. It elucidates the physiochemical significance and mathematical meaning of the parameters in the ENSIC model. In this article, the ENSIC approach has been proven to agree extremely well with the experimental data in both correlating the finite dilution solvent activity coefficient and predicting the infinite dilution solvent activity coefficient for rubbery polymer/solvent systems. In other words, both the ENSIC equation and its derivative at extremely low solvent concentration are in good agreement with the experimental data. In addition, the article indicates that the ENSIC model is much more accurate than another kind of empirical models‐ the F–H and related models in predicting the infinite dilution solvent activity coefficients in polymer solutions. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1668–1675, 2006     

Nonstationary diffusion of polystyrenes through a cellophane membrane

Diffusion of five polystyrene fractions at various concentrations in toluene through cellophane membranes has been observed. The results have been used to calculate friction coefficients between solvent and solute, and between solute and membrane. The calculation requires measurement of the diffusion coefficient and the reflection coefficient of the solute, of the permeability for the solvent, of the pore volume of the membrane, and of the partition coefficient of the solute between membrane and solvent. By comparing the friction coefficient between solvent and solute in the membrane with this coefficient in free solution, the tortuosity factor and the pore diameter of the membrane can be estimated. The dependence of the friction coefficients on molecular weight M₂ of the solute is determined. For large values of M₂, the friction between solute and solvent is the determining factor. The friction coefficient between solute and solvent increases more strongly with M₂ in the membrane than in free solution owing to an entrance effect for the permeating solute at the interface.     

Cp*TiCl2N[Si(CH3)3]2/MAO催化剂合成无规聚丙烯弹性体

合成了Cp TiCl2 N[Si(CH3) 3]2 甲基铝氧烷 (MAO)催化体系 ,以该体系进行丙烯聚合得到无规聚丙烯 ,具有高的分子量及良好的弹性 ,玻璃化温度为 - 8 8℃ .产物经DSC、1 3C NMR、DMA等方法表征 .结果表明 ,催化活性随着丙烯压力的增加 ,有明显的增大 .催化活性在 4 0℃下有最高的催化活性 ,而产物分子量随着温度的下降有明显增大 ,在 0℃～ 5 0℃范围内分子量MW =(2 0～ 6 0 )× 10 4 .     

三元体系NaCl-KCl-H2O35℃活度系数的研究

研究了35℃ NaCl-KCl-H2O三元体系的活度系数.用Na+、 K+和Cl-的离子选择性电极分别测得了(0.1～ 1.5 mmol/L)不同离子强度下该体系中NaCl和KCl的平均活度系数.回归了该体系Pitzer方程的相互作用参数.实验值与计算值最大相对误差为5.6%,而平均相对误差为2.3%.     

SOLVENT QUALITY AND SOLUTION BEHAVIOR OF NYLON 12

The refractive index increment,dynamic and static laser light scattering,intrinsic viscosity[η]and Huggins constant(K_H)of nylon 12 have been measured in m-cresol and sulphuric acid/water system at 10-60℃.The intrinsic viscosity,R_H,R_g,A_2,and(~2)~(1/2)(calculated from viscosity data)and"a"values of nylon 12 are found to be higher in m-cresol than in sulphuric acid.All these parameters decrease with the increase in water contents in sulphuric acid.The refractive index increment,K_H and activation energy show an opposite trend to that of[η].The intrinsic viscosity,R_H,R_g,A_2, and(~2)~(1/2) have maximum values around 30-40℃in sulphuric acid/water system,whereas in m-cresol they fall at about 20℃.It has been concluded that the variation in size,interaction parameter(second virial coefficient),[η]and K_H of the polymer solutions with the alteration in solvent composition and temperature are the out come of change in thermodynamic quality of solvents,selective adsorption,hydrogen bonding and conformational transitions.It has also been concluded that the increase in temperature first enhances the quality of the solvent,encourages hydrogen bonding and specific adsorption, and then deteriorates,bringing conformational transitions in the polymer molecules.However,the addition of water to sulphuric acid continuously deteriorates the solvent quality.This characteristic of the solvent system brings conformational changes in the polymer especially at low temperatures.     

LLE for the extraction of alcohol from aqueous solutions with diethyl ether and dichloromethane at 293.15 K, parameter estimation using a hybrid genetic based approach

Experimental liquid-liquid equilibrium (LLE) data for the extraction of methanol, ethanol and 1-propanol from water by diethyl ether and dichloromethane at 293.15 K and at ambient pressure were investigated. Data for the binodal curves have been determined by cloud-point titration method and conjugate points on tie-line were obtained by correlating the refractive index of the binodal curves as a function of composition. The experimental ternary (liquid + liquid) equilibrium data have been estimated using the NRTL and UNIQUAC activity coefficient models to obtain the binary interaction parameters of these components by a combination of Levenberg-Marquardt method and the genetic algorithm based method. The distribution coefficients and the selectivity factor of the solvent used were calculated and presented. From our experimental and calculated results, we conclude that for the extraction of alcohol from aqueous solutions with dichloromethane solvent has a higher selectivity factor than the diethyl ether solvent.     

Preparation and characterization of highly photoactive nanocrystalline TiO_2 powders by solvent evaporation- induced crystallization method

Highly photoactive bi-phase nanocrystalline TiO2 photocatalyst was prepared by a solvent evaporation-induced crystallization (SEIC) method, and calcined at different temperatures. The obtained TiO2 photocatalyst was characterized with X-ray diffraction (XRD), transmission electron microscopy (TEM) and BET surface areas. The photocatalytic activity was evaluated by the photocatalytic oxidation of acetone in air. The results show that solvent evaporation can promote the crystallization and phase transformation of TiO2 at 100℃. When calcination temperatures are below 600℃, the prepared TiO2 powders show bimodal pore size distributions in the mesoporous region. At 700℃, the pore size distributions exhibit monomodal distribution of the inter-aggregated pores due to the collapse of the intra-aggregated pores. At 100℃, the obtained TiO2 photocatalyst by this method shows good photocatalytic activity, and at 400℃, its photocatalytic activity exceeds that of Degussa P25. This may be attributed to the fact t     

Solvent extraction of thiophene from n-alkanes (C7, C12, and C16) using the ionic liquid [C8mim][BF4]

In the last years, new strict environmental regulations to reduce sulfur content in liquid fuels have been established. Thiophene derivates can be considered as the key substances to be separated from liquid fuel oils. This paper reports the ability of the ionic liquid 1-methyl-3-octylimidazolium tetrafluoroborate to act as solvent in the (liquid + liquid) extraction of thiophene from aliphatic hydrocarbons. Tie-line data have been determined for ternary systems containing the ionic liquid, thiophene, and some n-alkanes at T = 298.15 K. Extraction process has been analyzed by means of thiophene distribution ratio and selectivity. The solute distribution coefficient decreases and the selectivity increases as the chain length of n-alkane increases. The use of 1-methyl-3-octylimidazolium tetrafluoroborate as potential solvent for separation of thiophene from n-alkanes is feasible using the necessary quantity of solvent. A correlation of the equilibrium data reported here has also been made, using the NRTL activity coefficient model, in order to facilitate their use in simulation and design processes.     

采用电位滴定法在DMSO/H2O混合溶剂体系中测定磺酰脲(胺)类除草剂的酸离解常数

采用电位滴定法在DMSO/H₂O(质量比80:20)混合体系中测定了磺酰脲和三唑并嘧啶磺酰胺类除草剂的酸离解常数,进而采用回归分析方法探讨了测得的pK_a值与化合物的前沿轨道能级以及取代基效应之间的相关性,结果较为满意,从而证明从该体系测得的pK_a值用于构效关系分析是完全可行的.     

红栓菌多糖的分级、表征、分子链构型参数和抗癌活性研究

本文研究了以水为溶剂,乙醇为沉淀剂,获得6个级分的红栓菌多糖,并运用动态膜渗透压法、VPO法、超速离心沉降法、小角激光光散射和高效液相色谱等,对其进行了表征。使用分光光度计,以浊点滴定法与修正的Elias公式确定红栓菌多糖溶液的θ组成为:V_(H_2O):V_(CH_3COCH_3)=89.82:10.18(体积比)。再在θ条件下建立红栓菌多糖的Mark-Houwink方程:[η]=5.01×10~(-4)M~(0.502)计算出它的无扰尺寸。由色谱法和董履和函数适应法解得红栓菌多糖的分子量分布。 通过抗癌药理活性实验,发现该多糖对小白鼠肉瘤S_(180)有较强的生理活性,能抑制肿瘤生长。同时还发现多糖Ⅱ活性高于多糖Ⅰ活性。