一个物理化学设计实验的探讨与改进——离子液体溶液平均活度系数的测定

文章制备了溴化1-十二烷基-3-甲基咪唑[C12mim]Br和1-十二烷基-3-甲基咪唑四氟硼酸盐[C12mim][BF4]两种离子液体。在不同温度下,测定了两种离子液体水溶液的电导率,根据电导率-浓度曲线转折点求出了两种离子液体水溶液的临界胶束浓度。由Debye-Hücker和Osager-Falk-enhangen公式计算出离子液体的平均活度系数。结果表明：[C12mim]Br和[C12mim][BF4]的水溶液临界胶束分别为5.75×10-3 mol·L-1和6.00×10？3 mol·L-1。25℃下,平均活度系数随浓度的增大而降低。     

浙江大学聚合物分离膜材料表界面工程团队:渗透压驱动的水溶性离子液体高效回收新方法

近日,浙江大学聚合物分离膜材料表界面工程团队通过密度泛函理论计算以及分子动力学模拟,发现与无机盐相比,离子液体具有较弱的水合作用,同时,其水溶液在临界胶束浓度下倾向于形成胶束化的聚集体。在此基础上,分别以饱和无机盐水溶液和离子液体水溶液作为汲取液和进料液,可在半透膜的两侧形成巨大的渗透压差,驱动水分子向无机盐侧渗透,从而实现对离子液体水溶液的浓缩。     

长链离子液体临界胶束浓度研究

采用毛细上升法测定[Cn MIm]Br(n=12,14,16)3种长链离子液体与十二烷基硫酸钠(传统阴离子表面活性剂)的表面张力,通过表面张力拐点得到临界胶束浓度。结果表明,长链离子液体与传统表面活性剂临界胶束浓度相当;在临界胶束浓度下,长链离子液体表面张力相差不大,且都略小于传统表面活性剂,则其表面活性优于传统阴离子表面活性剂。     

长链离子液体临界胶束浓度研究

采用毛细上升法测定[Cn MIm]Br(n=12,14,16)3种长链离子液体与十二烷基硫酸钠(传统阴离子表面活性剂)的表面张力,通过表面张力拐点得到临界胶束浓度。结果表明,长链离子液体与传统表面活性剂临界胶束浓度相当;在临界胶束浓度下,长链离子液体表面张力相差不大,且都略小于传统表面活性剂,则其表面活性优于传统阴离子表面活性剂。     

水相和特殊介质中有序聚集体的结构、性质和应用（Ⅰ）——表面活性剂在水相和离子液体中的有序聚集体

首先介绍了表面活性剂溶液性质和各种聚集体结构,其中包括胶束、微乳液、囊泡和溶致液晶等,以及聚集规则———临界堆积参数等。同时介绍了表面活性剂在离子液体中形成的各种典型有序聚集结构,特别阐明在室温下表面活性剂在水溶液和离子液体中聚集形成的有序聚集体的异同点;另外还介绍了利用表面活性剂在离子液体中形成的聚集体作为模板制备微纳颗粒。     

含胺功能基团离子液体表面活性剂的合成及性能

本文研究了三种含胺功能基团的离子液体表面活性剂的合成方法,并利用红外光谱仪和滴体积法对其官能团结构和水溶液表面张力进行表征.结果表明,表面活性剂在波数1338、1234、1465和3142cm-1处具有咪唑环的C-N、C-H特征吸收峰,具备离子液体的结构特征.表面张力等温曲线证实,随着碳链的增长,临界胶束浓度(CMC)...     

离子液体型表面活性剂的研究进展

离子液体型表面活性剂是一种功能性离子液体,具有离子液体的特性,还具有双亲特性.简述了离子液体型表面活性剂的制备方法,在此基础上,重点综述了离子液体型表面活性剂的表面吸附、临界胶束浓度、表面张力等表面性能;同时介绍了离子液体型表面活性剂在微乳液聚合和酶催化反应中的应用,并对离子液体型表面活性剂的发展方向进行了展望.     

GSS362/TX-100复配体系在水中的溶液行为研究

研究了1,3-丙二醇双子琥珀酸二异辛酯磺酸钠(GSS362)和辛基酚聚氧乙烯醚(TX-100)复配物在水中的表面性质和胶束化行为,并对理想混合临界胶束浓度以及混合体系中各组分在表面吸附层和胶束中的组成、相互作用参数和热力学参数进行分析计算。结果表明,复配物在水溶液中不存在协同效应,但是TX-100的加入明显降低了GSS362的临界胶束浓度,混合胶束的形成为自发过程,胶束中GSS362与TX-100分子具有较弱的相互作用,胶束中富含非离子表面活性剂TX-100。     

表面活性剂的复配及对甲维盐微乳剂物理稳定性的影响

通过测定不同类型的单一及复配型表面活性剂水溶液的临界胶束浓度和表面张力,研究了它对w(甲维盐)=1％的微乳剂物理稳定性的影响。膦酸酯类阴离子表面活性剂A的临界胶束浓度为1．79×10-4 mol／L,表面张力为28．90 mN/m;苄基酚聚氧乙烯聚氧丙烯醚嵌段型非离子表面活性剂B(EPE型)的临界胶束浓度为 1.91×10-4 mol/L,表面张力为20．70 mN/m;按m(A):m(B)=2:3形成的复配型表面活性剂2#的水溶液的临界胶束浓度为9．30×10-5 moL/L,表面张力为25．66 mN/m。当w(2#)=10％时,配制w(甲维盐)=1％的微乳剂物理稳定性最佳,各项指标均合格。     

离子液体中淀粉-g-聚己内酯共聚物的制备及表面活性研究

以1-丁基-3-甲基咪唑溴化物([bmim]Br)离子液体作为淀粉(St)和己内酯(CL)的共溶剂,合成了生物可降解的淀粉/聚己内酯接枝共聚物(St-g-PCL)。研究了St/CL/[bmim]Br投料比对单体转化率、接枝率以及产物溶解性的影响,利用1HNMR和IR考察了产物的结构和St-g-PCL中CL与淀粉单元的摩尔比。表面张力法测定了St-g-PCL水溶液的表面张力和临界胶束浓度,并通过稳态芘荧光分析了胶束内核的疏水环境。结果表明:当投料比St/CL/[bmim]Br=10/14/20(w/w/w),接枝率为65%,St-g-PCL中CL与St结构单元摩尔比为0.91/1,产物具有较好的水溶性,St-g-PCL水溶液的表面张力(γcmc)和临界胶束浓度(CMC)分别为32.7mN/m,0.64mg/ml。所形成的胶束内核具有较好的疏水环境。     

鼓泡反应器中幂律型流体流动与传质特性

很多废水处理装置涉及非牛顿型流体中的多相流动和传质问题,研究其中的气液传质过程有助于实现装置的优化设计和高效节能运行。以鼓泡反应器内清水和不同质量分数的羧甲基纤维素钠（CMC）水溶液为实验对象,分别研究气相表观气速和液相流变特性对气泡尺寸分布、全局气含率和体积氧传质系数的影响。实验结果表明,液相的流变特性对其传质特性参数均有较大影响。与清水相比,CMC水溶液中气泡平均直径和分布范围更大;清水和CMC水溶液的全局气含率均随表观气速的增加而增大;CMC水溶液的体积氧传质系数随CMC水溶液质量分数的增加而减小。基于实验研究,得出修正的体积氧传质系数公式和适用于幂律型非牛顿流体流动体系氧传递过程的无量纲关联式,可很好地实现非牛顿流体流动的废水处理装置中气液传质参数的计算。     

离子液体水溶液-气体水合物对CO2的双捕获工艺

设计了以离子液体[APMIM]Br水溶液吸收-生成水合物捕获CO2工艺流程,并利用CO2在该离子水溶液中的溶解度数据和在其中生成CO2水合物的相平衡实验数据进行物料衡算. 考察了水含量、压力和液气流量比对气体吸收-水合物生成的CO2双重捕获效果的影响,对比了气体水合物与离子液体水溶液捕获CO2的能力. 结果表明,在较高压力和水含量条件下,水合物捕获CO2的效应强于离子液体溶液;较低压力下离子液体溶液吸收CO2起主要作用. 与纯水合物法相比,双捕获工艺具有一定优势,且突破了单纯水合物脱碳的压力和CO2含量要求高的局限性. 当原料气中CO2低于65%(j)时,系统的脱碳效率低于40%,对于CO2含量较低的气体,其CO2的脱除性能回归至单纯离子液体溶液体系.     

Determination of critical micelle concentrations of some nonionic surfactants by Keto-Enol tautomerism of benzoylacetoanilide

The absorbances of benzoylacetoanilide, keto-enol tautomer, dissolved in aqueous solution of several concentration ranges below and above the CMC of the incorporating surfactants. Below the CMC, the absorbance of the band at 250 nm due to the ketonic form showed hardly any change and that of the band at 320 nm due to the enolic form could not be observed. In contrast, above the CMC, the spectral band of the enolic form appeared, and the absorbance increased abruptly and that due to the ketonic form decreased gradually. The changes at the CMC in absorbance for these nonionic surfactants were distinctly observed by plotting the absorbance at 250 and 320 nm as a function of the concentration of surfactants. These changes at the CMC were very noticeable with nonionic surfactants as well as with ionic surfactants. The concentrations corresponding to break points for these surfactants were in fairly good agreement with the published data of the CMC of each surfactant. This method of keto-enol tautomerism using benzoylacetoanilide has been confirmed CMC for most anionic, cationic, and nonionic surfactants.     

Extraction of anionic dyes with ionic liquid–nonionic surfactant aqueous two-phase system

The cloud point of nonionic surfactant (Triton X-114) in ionic liquid ([Bmim]Cl) aqueous solution exhibits as increase and then decrease and increase again with the increase of ionic liquid (IL) content, which is the origin of an IL–nonionic surfactant aqueous two-phase system. The nonionic surfactant-rich phase coexists with a high content of IL aqueous solution phase in the IL–nonionic surfactant aqueous two-phase system. The partitioning of various ionic dyes indicates that anionic species exhibit a high partitioning coefficient between the IL-rich phase and the nonionic surfactant-rich phase.     

Hydrogel of biodegradable cellulose derivatives. I. Radiation‐induced crosslinking of CMC

Radiation crosslinking of carboxymethylcellulose (CMC) with a degree of substitution (DS) from 0.7 to 2.2 was the subject of the current investigation. CMC was irradiated in solid‐state and aqueous solutions at various irradiation doses. The DS and the concentration of the aqueous solution had a remarkable affect on the crosslinking of CMC. Irradiation of CMC, even with a high DS, 2.2 in solid state, and a low DS, 0.7 in 10% aqueous solution, resulted in degradation. However, it was found that irradiation of CMC with a relatively high DS, 1.32, led to crosslinking in a 5% aqueous solution, and 20% CMC gave the highest gel fraction. CMC with a DS of 2.2 induced higher crosslinking than that with a DS of 1.32 at lower doses with the same concentration. Hence, it was apparent that a high DS and a high concentration in an aqueous solution were favorable for high crosslinking of CMC. It is assumed that high radiation crosslinking of CMC was induced by the increased mobility of its molecules in water and by the formation of CMC radicals from the abstraction of H atoms from macromolecules in the intermediate products of water radiolysis. A preliminary biodegradation study confirmed that crosslinked CMC hydrogel can be digested by a cellulase enzyme. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 278–283, 2000     

鼓泡塔中低浓度表面活性剂对CO2吸收传质系数的影响（英文）

The effect of different surfactants (n-octyltrimethylammonium bromide (OTABr), sodium dodecyl benzene sulfonate (SDBS) and Tween 80) with different critical micelle concentrations (CMC) on the CO2 absorption into aqueous solutions in a bubble column is analyzed in the present work. The presence of these surfactants in-creased the gas–liquid interfacial area, and decreased the liquid phase mass transfer coefficient, but with signif-icant different extent. The results indicated that the CMC can be a key parameter affecting the mass transfer of CO2 absorption into a dilute aqueous solution of a surfactant. Sardeing's model was used to fit the experimental data successfully by re-correlating the parameters.     

1-氨丙基-3-甲基咪唑溴盐水溶液的汽液相平衡

1-氨丙基-3-甲基咪唑溴盐([APMIm][Br])是一种对CO₂有良好吸收性能的功能型离子液体,在工业中可采用水溶液来实现高效能的吸收和解吸循环过程,因此对其水溶液特性的研究至关重要。对[APMIm][Br]水溶液在中低温度下的汽液相平衡进行了测量,获得可靠的实验数据,从而揭示其水溶液特性。实验温度范围为278.15～348.15 K,[APMIm][Br]在水溶液中质量分数分别为10.0%、20.3%、29.5%、40.0%、57.5%、75.3%、84.0%、88.9%、90.9%。考虑了低温下离子液体分子在水溶液中的强缔合特性,采用带缔合惰化因子的离子液体水溶液活度模型对实验数据进行了拟合,实验值与计算结果符合很好,平均相对误差为2.15%。     

咪唑类[PF_6]^-型离子液体萃取苯胺

研究了以咪唑类[PF6]-型室温离子液体1-丁基-3-甲基咪唑六氟磷酸盐（[Bmim][PF6]）、1-己基-3-甲基咪唑六氟磷酸盐（[Hmim][PF6]）和1-辛基-3-甲基咪唑六氟磷酸盐（[Omim][PF6]）对苯胺水溶液的萃取平衡。实验结果表明：pH值对分配系数的影响很大,在碱性条件下,分配系数较高;萃取过程属于吸热过程;经过四级错流萃取,废水可达到排放标准,萃取相中的苯胺回收率在90%左右,离子液体回收率〉90%,离子液体可以循环利用。     

分光光度法研究十二烷基硫酸钠的临界胶束浓度

在碘的水溶液和I<'-><,3>溶液2种体系中测定了十二烷基硫酸钠(SDS)的临界胶束浓度(CMC),并讨论了在I<'-><,3>体系中,不同硫酸钠和氯化钾2种盐对测定结果的影响,在碘的水溶液中研究了不同碘浓度对SDS的CMC的影响.采用分光光度法求得SDS在两种体系中的CMC值,硫酸钠与氯化钾对CMC的值有影响,且无...