乙酰水扬酸在CTAB胶束溶液中的水解反应

乙酰水扬酸(阿斯匹林)具有较高的药用价值,对它的性质有较多的研究,如在水中的稳定性和水解等。乙酰水扬酸有一个脂键和一个羰基。脂键易水解,水解后药用价值虽未降低,但有很大的副作用,因而研究抑制乙酰水扬酸水解是很有意义的。本文用RD—Ⅲ型热导式自动量热计研究了在十六烷基三甲基溴化胺(CTAB)胶束溶液中乙酰水扬酸的水解反应热动力学。     

OXYGEN QUENCHING IN MICELLAR SOLUTION AND ITS EFFECT ON THE PHOTOCYCLIZATION OF N-METHYLDIPHENYLAMINE

Abstract— Oxygen effects on the photocyclization of N-methyldiphenylamine to N-methylcarbazole were investigated in n-hexane, water, and aqueous surfactant solutions by steady state irradiations and flash photolysis measurements. The reaction sequence in micelles was found to involve the same intermediate steps as in homogeneous solutions. In aerated micellar solutions, the quantum yield of N-methylcarbazole is significantly higher than in n-hexane, while the rate constants of the unimolecular reaction steps show no solvent dependence. The bimolecular dehydrogenation of the intermediate 4a, 4b-dihydro-N-methylcarbazole by oxygen is enhanced in aqueous and micellar solutions, whereas the quenching rate of triplet intermediates by oxygen was not affected. The lesuhs are interpreted using a dispersed phase model of micellar solutions. Special 'micellar effects' need not be invoked since the dependence of the quantum yield on the solvent is shown to be due to the difference in the overall oxygen concentration.     

嵌段结构对两亲嵌段共聚物水溶液行为的影响

在合成了二种具有相同组成不同嵌段结构排布的共聚物基础上对它们溶液的物理化学行为用荧光探针的方法进行了研究，结果表明：由于结构排布的不同其物理化学行为有着较大的差异，三嵌段结构的共聚物较二嵌段者更易于形成胶束体系，而二嵌段共聚物则易于发生凝胶化，对上述结果进行讨论和解释．     

添加剂对十二烷基磺酸钠溶液性质影响的研究

添加剂对十二烷基磺酸钠溶液性质影响的研究＊鲁润华郝京诚汪汉卿（中国科学院兰州化学物理研究所兰州７３００００）关键词表面张力电导添加剂Ａｓ中图分类号Ｏ５５２．４添加剂对表面活性剂溶液物理化学性质影响的研究是人们极感兴趣的研究内容［１］，因为表面活性剂实...     

两亲性梳形共聚物PASP-Na-g-DDA的合成及接枝率对其水溶液胶束性质的影响

天冬氨酸自身缩聚产物聚琥珀酰亚胺(PSI)与十二胺(DDA)发生氨解反应,该氨解产物在碱性条件下水解,制得了一种两亲性梳形共聚物PASP-Na-g-DDA.通过改变DDA与PSI的比例,合成了一系列不同接枝率的两亲性梳形共聚物.用核磁共振(1H-NMR)及凝胶渗透色谱(GPC)对共聚物的结构进行了表征.随着疏水链段DD...     

EFFECT OF CRYOGENIC AND HEATING TREATMENT ON THE SOLUTION PROPERTIES OF NITROCELLULOSE

The effect of cryogenic and heating treatment on the solution properties of rigid polymer nitrocellulose (NC) in dilute tetrahydrofuran solution were studied with a sealed viscometer and a size exclusion chromatograph (SEC),respectively. The experimental results show that the relative viscosity of NC solution decreases after repeated freezing-thawing treatment. The decreased viscosity value of NC could not be restored but decreased further after the solution being re-heated. The experimental results of SEC are fully consistent with that of viscosity measurements. It is believed that the effect of two treatments on NC solution both causes the apparent hydrodynamic volume to decrease. But they are assumed to be ascribed to different mechanisms.     

STUDIES ON THERMOKINETICS(XVI) THE KINETICS OF THE POLYMERIZATION OF ACRYLAMIDE IN MICELLAR SOLUTION

The kinetics of the polymerization of acrylamide in aqueous solution and CTAB micellar solution initiated by sodium sulfite has been investigated with the theory and method of thermokinetics for n order reactions with equal concentration in this paper. The influence of initiator and CTAB concetrations on molecular weight of polyacrylamide has been discussed.The second—order rate constants of this reaction at 30 and 40°C in aqueous solution are 0. 112and 0. 0262dm³ mol^-1s^_1, respectively. The activation energy,based on measurements at these two temperatures,is 66. -4kJ mol^-1. The ratio k2√n in CTAB micellar solution is smaller than that in aqueous solution. The rate of forming radical in micellar solution has been decreased.     

聚肽嵌段共聚物中肽链构象对其自组装行为的影响

两亲性聚肽嵌段共聚物具有良好的生物相容性、生物安全性和可生物降解性,其在选择性溶剂中自组装形成的胶束在药物控释载体方面有着良好的应用前景[1~4].Cho等研究了聚(L-谷氨酸-γ-苯甲酯)(PBLG)-聚氧化乙烯(PEO)嵌段共聚物(PBLG-b-PEO)在水中的自组装性能,发现PBLG-b-PEO在水     

高速搅拌对淀粉/聚乙烯醇共混物溶液成膜性能的影响

淀粉与聚乙烯醇（ＰＶＡ）溶液在高速搅拌下共混,可大大改善淀粉／ＰＶＡ共混薄膜的力学性能、透明性与耐水性,对其生物降解性有明显的影响．淀粉／ＰＶＡ共混体系在高速搅拌前后的光谱分析、显微观察、分子量及流变性能的测定表明,这些变化起因于高速搅拌增加了淀粉中直链淀粉的含量,同时提高了淀粉与ＰＶＡ共混溶液的稳定性,改善了淀粉／ＰＶＡ共混物薄膜的使用性能．     

煤的岩相显微组分对水煤浆性质的影响

通过对不同变质程度煤的岩相显微组分分析，考察了煤的岩相显微组分对水煤浆性质的影响。结果表明，在相近的灰分含量下，对于烟煤较高的镜质组、较低的丝质组含量有利于煤的成浆性和稳定性。从多元线性回归结果来看，镜质组和丝质组的含量对煤浆成浆性和流变性的影响较为明显，稳定组分的含量对水煤浆性质的影响较小。丝质组含量对稳定性作用明显，当煤中丝质组含量低于30%时，煤浆产生软沉淀的时间一般都在15d以上。煤的平均最大镜质组反射率与煤的成浆性具有较好的相关性，成浆性随煤的最大镜质组反射率增加而增加，因此可以用最大镜质组反射率来预测煤的成浆性。     

H2SO4溶液中F-离子对Pb及Pb-Sb电极表面膜影响的研究

Pb-Sb板栅的耐腐蚀性能是影响铅蓄电池寿命的重要原因之一。关于不同Pb合金电极的研究已有不少工作。关于H₂SO₄溶液中添加剂的研究,除H₃PO₄以外,其它一些添加剂的研究不多。鉴于F^-离子的特殊性,我们研究了电解液中F^-离子对Pb、Pb-Sb电极的影响。     

STUDY ON THE CONFORMATIONAL PROPERTIES OF RIGID POLYELECTROLYTE SPU IN SOLUTION

The conformation and dimension of SPU polyanion have been studied by viscosity and quasi-elastic light scattering methods. The rigidity of SPU is somewhat similar to CMC and its hydrodynamic radius decreases only slowly with increasing concentration of NaCl.     

水中二氧化碳含量对弱碱性阴树脂工作交换容量影响的研究

弱碱性阴树脂用于水的除盐处理时，其工作交换容量的大小与许多因素有关。本文主要就进水中ＣＯ２含量对弱碱阴树脂工作交换容量的影响进行了研究，得出了弱碱性阴树脂工作交换容量受水中ＣＯ２含量影响的一般规律，这为弱碱性阴树脂的应用提供了依据。     

EFFECT OF HYPERCROSSLINKED RESINS SURFACE CHEMISTRY ON THE ADSORPTION OF PHENOL FROM AQUEOUS SOLUTION

Two hypercrosslinked resins with similar physical characters but different surface chemistry were synthesized and used to remove phenol from aqueous solutions. The FTIR spectra, elemental analysis and the Boehm titration were used to characterize the chemical properties of the resins. The adsorption experiments were carried out using the bottle-point technique, and the effects of the surface chemistry on the adsorption were discussed. The adsorption data fit well with the Freundlich model, indicating the heterogeneity of the resins surface. It could be seen from the experimental results that the adsorption capacity increased with the increase in the total surface concentration of oxygen-containing groups. The pH dependence and the effects of ionic strength were also discussed. The kinetic adsorption data fit well with the pseudo-second order model, and the results showed that the surface oxygen-containing groups have little effect on the adsorption rate.     

支化高分子在溶液中的交叠与缠结

溶液中高分子的交叠和缠结与其链结构密切相关。支化聚苯乙烯的临界交叠浓度C和临界缠结浓度C_E比分子量相同的线型聚苯乙烯的大,说明交叠和缠结同分子在溶液中线团的体积有直接关系。     

混合煤制浆对水煤浆性质的影响

实验选用三种性能较差，不适宜制浆的煤作为原料煤，选用成浆性、稳定性或流变性较好的三种煤作为配煤进行混合煤制备水煤浆。实验结果表明，在相同的制浆条件下，加入成浆性、稳定性较好的煤种，使得水煤浆性质较差的煤成浆性、稳定性均有不同程度的提高，浆体流变性得到改善，煤浆粘度明显降低。根据配煤加入量的不同，煤的成浆浓度可提高约2%～3%，浆体稳定性增加，产生软沉淀的时间由1 d提高到10 d。加入成浆性较差的褐煤，亦可明显提高难制浆煤种的稳定性和改善浆体的流变性，使得浆体由胀塑性流体变为假塑性流体。煤的表面性质分析表明，配入表面性质差异较大的煤种，有利于改善难制浆煤种的水煤浆性质。     

基团贡献法研究环型聚苯乙烯稀溶液流体力学参数

首次采用基团贡献法,根据内聚能、摩尔体积、摩尔吸引常数和临界特性粘数等分别计算并通过实验数据验证了环型和线型聚苯乙烯的溶度参数,特性粘数、摩尔极限粘数函数、临界分子量和Mark-Houwink参数,详细地讨论了计算大环高分子的K_(θ,r)值所取用的临界分子量应具有的理论意义。     

THE EFFECT OF POLYMER ON THE CLOUD POINT OF A SERIES OF TRIBLOCK NONIONIC SURFACTANTS IN AQUEOUS SOLUTION

A series of triblock nonionic surfactants with different Propylene oxide and ethylene oxide chain lengths were synthesized. The triblock nonionic surfactants and poly(ethylene glycols) with different molecular weight were used, to find the effects of polymer chain length and size of the micelles on the cloud point of the surfactants. Two possible models are considered on the basis of cloud point changes of the solutions, to describe the polymer- surfactant interactions. One model suggests that flocculation depletion for the polymer chains exist between two regular micelles. This provides the driving force for the neighboring micelles to approach each other and destabilize the colloidal system. The flocculation effect is more important for polymers with a shorter chain block the approach of the micelles, since there is no typical polymer-surfactant association formed but just simple small molecule associations in which the steric and solvation effects of the polymer chains make the inter-micelles interactions repulsive. The other model considers that intra-chain micelles of polysoap are formed among the surfactant monomers and long polymer chains. The bridging attraction between two intra-chain micelles in such structures can enhance the collisions among the micelles, due to the exchange of amphiphilic monomers among the neighboring micelles.     

树脂法再生贮氢合金材料包覆液工艺中树脂吸附性能研究

本文研究并探讨了NK-ELN型离子交换树脂在再生贮氢合金材料包覆液过程中，温度、流速、溶液中离子浓度等条件对树脂交换容量和再生效率的影响，为树脂法再生贮氢合金材料包覆液工艺的制定，提供了一系列重要参数。     

疏水链段对两亲性三嵌段共聚物在水中聚集行为的影响

以结构明确的两端为短的聚苯乙烯(PS)或聚甲基丙烯酸甲酯(PMMA)链段,中间为长的聚乙二醇(PEG)链段的PS-b-PEG-b-PS和PMMA-b-PEG-b-PMMA两亲性三嵌段共聚物为对象,研究了PS和PMMA链段对其在水中形成胶束和凝胶的影响.两种三嵌段共聚物在水中形成以PS或PMMA链段为核、PEG链段为壳的球形胶束,流体力学半径Rh,app为15.3~24.3 nm,并随PEG链段长度增长而增大.临界胶束浓度CMC均小于0.01 mg/mL,随着PS和PMMA链段长度的增加而减小.PS-b-PEG-b-PS浓度高于4.5 wt%可形成较强的疏水缔合的物理凝胶,平衡模量Ge可达到103Pa;PMMA-b-PEG-b-PMMA浓度高于7.5 wt%可以形成弱的凝胶,Ge<10 Pa.凝胶的储存模量G′和损耗模量G″均随着PS或PMMA链段的增长而增大.