PH敏感性水凝胶的分子热力学模型

本工作是在非离子凝胶的分子热力学模型基础，引入Ｄｏｎｎａｎ平衡项和大分子离子链的静电排斥项对凝胶自由能的贡献，建立了一个新的离子凝胶的分子热力学模型。该模型在解释离子凝胶的ＰＨ敏感性及其各种影响因素，以及预测ＰＨ溶胀曲线方面都取得了较好的效果。     

新型吸-放热复合发泡剂的特性分析与应用

对自制的新型吸－放热复合发泡剂ＨＣＢ－ＮＸ的分解动力学和热力学特性进行了研究,同时对采用该发泡剂进行硬质聚氯乙烯低发泡挤出的特性及泡孔结构进行了分析。     

基于CaO引导的甲烷蒸汽重整化学链燃烧制氢系统

为在重整气中得到高纯H_2和降低尾气CO_2分离成本,建立了基于CaO引导的甲烷蒸汽重整化学链燃烧制氢系统,该系统在重整反应器中加入CaO吸收剂,用以吸收重整器内的CO_2,提高重整气中H_2浓度,形成的CaCO_3固体在煅烧器中受热分解重新生成CaO。利用Aspen Plus进行了过程模拟及热力学分析,并研究主要参数对系统性能的影响,得到优化的操作条件为:CaO循环量/CH_4比为0.5,CH_4(燃料)/CH_4比为0.35,NiO循环量/CH_4比为1.4。CaO循环量/CH_4比从0变化到0.5时,重整气中H_2浓度从0.60增长到0.99;CH_4(燃料)/CH_4比在0.25~0.45区间变化时,重整气中H_2浓度从0.86提高到0.99,产气量增加;NiO循环量/CH_4比在1~1.6区间变化时,重整气中H_2浓度从0.88增长到0.99,系统有效能效率变化较小。     

石蜡沉积对储层渗透率的影响研究

油气开采过程中的蜡质、沥青质等有机固相沉积。严重影响着油田的正常生产。固相沉积物不仅堵塞油井、输油管线,而且也给油藏多孔介质造成一系列的伤害。如堵塞油藏孔隙、降低孔隙度和渗透率,改变油藏岩石的润湿性,从而影响原油采收率的提高。本文采用热力学理论建立了液固两相相平衡方程,模拟计算石蜡沉积量对储层孔隙度和渗透率影响,进而求出对油井产能的影响。     

荧光光谱法研究茶碱与血红蛋白的相互作用

运用荧光光谱法研究了茶碱与牛血红蛋白(BHb)的相互作用,茶碱对牛血红蛋白的荧光猝灭过程主要为静态猝灭。测定了不同温度下该反应的结合常数、结合位点数及结合热力学参数,热力学参数的变化,表明上述作用过程是一个熵增加、自由能降低的自发分子间作用过程,而且是以疏水作用为主。用同步荧光技术考察了茶碱对BHb构象的影响。     

Viscoelastic Behavior, Thermodynamic Compatibility, and Phase Equilibria in Block Copolymer-Based Pressure-Sensitive Adhesives

The viscoelastic behavior, thermodynamic compatibility, and phase equilibria in block copolymer-based pressure-sensitive adhesives were investigated. The block copolymers investigated were: (1) polystyrene-block-polybutadiene-block-polystyrene (SBS) copolymer (KRATON® D-1102, Shell Development Company) and (2) polystyrene-block-polyisoprene-block-polystyrene (SIS) copolymer (KRATON® D-1107, Shell Development Company). The tackifying resins investigated were: (1) WINGTACK® 86 (Goodyear Tire & Rubber Company) and (2) PICCOTAC® 95BHT (Hercules Inc.). Samples of various compositions were prepared by a solution-casting method with toluene as solvent. Measurements of dynamic storage modulus (G'), dynamic loss modulus (G'), and loss tangent (tan δ) were taken, using a Rheometrics Mechanical Spectrometer. It was found that: (1) both WINGTACK 86 and PICCOTAC 95BHT were equally effective in decreasing the plateau modulus (G^O_N), and increasing the glass transition temperature (T_g) of the polyisoprene midblock of KRATON 1107; and (2) WINGTACK 86 was very effective in decreasing the G^O_N and increasing the T_g of the polybutadiene midblock of KRATON 1102, whereas PICCOTAC 95BHT was not. The observed difference between WINGTACK 86 and PICCOTAC 95BHT in decreasing the G^O_N and increasing the T_g of the polybutadiene midblock of KRATON 1102, whereas PICCOTAC 95BHT was not. The observed difference between WINGTACK 86 and PICCOTAC 95BHT in decreasing the G^O_N and increasing the T_g of the polybutadiene midblock of KRATON 1102 (perhaps to SBS block copolymers in general) is explained by the values of the interaction parameter for WINGTACK 86 and KRATON 1102, and for PICCOTAC 95BHT and KRATON 1102. The interaction parameter was determined, using the piezoelectric quartz sorption method. Phase diagrams were constructed for the four block copolymer/tackifying resin systems investigated, using information obtained from both dynamic viscoelastic measurements and optical microscopy. It was found that when mixed with KRATON 1102, PICCOTAC 95BHT formed separate domains whereas WINGTACK 86 did not over the range of concentrations and temperatures investigated. This confirms the evidence obtained from two other independent experimental techniques, namely, dynamic viscoelastic measurements and the piezo-electric sorption method. We have concluded from the present study that PICCOTAC 95BHT is not as an effective tackifying resin as WINGTACK 86, when each is mixed with KRATON 1102. It is pointed out further that information on the order-disorder transition temperature T_r, which was determined from a rheological technique proposed by us, is valuable in determining optimal processing conditions for block copolymer-based pressure-sensitive adhesives.     

Preparation of dibasic acid-containing soy phospholipids by chemical and enzyme-catalyzed transesterification and evaluation of their surface-active properties

The preparation of dibasic acid-containing soy phospholipid was made by transesterification reaction with alkyl ester of diabasic acid with both lipase and alkoxide as a catalyst. The extent of incorporation of a dibasic acid varied with the molecular size of the dibasic acid. The extent of incorporation in soy phospholipids was 4–13% in the case of adipic acid and 9–20% in the case of sebacic acid. The surface-active properties of these modified soy phospholipids were examined and were found to be different from those of the original (unmodified) soy phospholipid. The interfacial properties such as critical micelle concentration (CMC), γ_CMC, surface excess concentration Γ_max, and minimum area per molecule (Å), and thermodynamic parameters such as standard free energy of micellization, were found to depend on the hydrophobic part of the dibasic acids.     

膜内介质传递现象

论述了组分在膜分离过程中的传递行为。简要论述了介质通过膜的途径，对膜传递过程中所产生的理论体系进行归纳和解释，并对其内在联系进行总结；最后根据介质与膜的相互关系，把组分在均质膜中的传递过程分为理想扩散过程、弱相互作用扩散过程、强相互作用扩散过程，并分别进行探讨。     

Thermoplastic extrusion—the mechanism of the formation of extrudate structure and properties

Systems processed by thermoplastic extrusion can be regarded as heterophase polymer melts of incompatible water-plasticized biopolymers. In the process of thermoplastic extrusion, proteins and polysaccharides are melted at high pressure and temperature below the temperature region of their thermal decomposition. Dispersed particles of these systems can be deformed in flow. The mixed-melt anisotropic structure, formed in flow, is fixed by rapid conversion of the melt jet that lets the extruder die from a viscous state to a rubber-like state and then to a glassy state caused by cooling and drying. Incompatibility of proteins and polysaccharides in their water-plasticized melt mixtures impacts on structure formation and texturization during thermoplastic extrusion. Presented at the 20th ISF World Congress and 83rd AOCS Annual Meeting and Expo, May 10–14, 1992, Toronto, Ontario, Canada.     

Properties of aqueous solutions for two binary mixed systems between two kinds of bile salts and nonionic surfactants

The micellar properties of aqueous binary mixed solutions for two systems consisting of sodium cholate (NaC)-octaoxyethylene glycol mono n-decyl ether (C₁₀E₈) and sodium glycocholate (NaGC)-C₁₀E₈ have been studied on the basis of surface tensions, polarity of the micelle interior and the mean aggregation number. Application of two theoretical treatments, based on regular solution and excess thermodynamic quantities for critical micellar concentration (CMC) data from surface tension curves of two mixed systems showed that the mole fraction of each bile salt in the mixed micelles near the CMC is lower than that of the corresponding prepared mole fraction in the mixed solution. The polarity of the interior suggested that the hydrophobicity of intramicelles increased with the increase of the mole fraction of bile salt in the mixed solution and that the mixed micelles become dramatically more hydrophobic at a mole fraction of 0.68 for NaGC−C₁₀E₈ system and 0.75 for NaC−C₁₀E₈ system, respectively. This implies that the micelles become richer in the bile salt molecules and the tendency appears strongly for NaGC−C₁₀E₈ system due to the strong cohesion between the conjugated glycines in the NaGC molecules. The decrease of aggregation number with the increase of the mole fraction of bile salts shows that the micelles approach those of the single system of each bile salt. This supports the previously mentioned facts.