新型中介结构层状硫化钨的合成与表征

利用钨酸钠与表面活性剂十六烷基三甲基溴化铵(CTAB)及硫代乙酰胺在水热条件下合成了一种中介结构层状硫化钨WS-L.通过化学及元素分析、红外光谱、光电子能谱、粉末X射线衍射、透射电镜、扫描电镜以及热重分析等方法进行表征.WS-L的化学式为WS_3.5·[C₁₆H₃₃N(CH₃)₃]₂,其中硫化钨所带负电荷被嵌插在层间的表面活性剂阳离子所平衡.     

正离子Gemini表面活性剂/负离子聚电解质相互作用的研究

摘要 采用荧光探针法和电导法研究了正离子偶联表面活性剂(C₁₂H₂₅(CH₃)₂N-(CH₂)₆-N(CH₃)₂C₁₂H₂₅•2Br) (12-6-12• 2Br^－)和带相反电荷聚电解质聚丙烯酸钠(NaPA)的相互作用, 结果表明: 由于静电相互作用, 12-6-12•2Br^－和NaPA之间可以形成类胶束或复合物. 对比十二烷基三甲基溴化铵(DTMAB)与NaPA复配体系的荧光光谱, 发现偶联表面活性剂与NaPA的相互作用强于传统表面活性剂. 此外, 还研究了盐和醇对偶联表面活性剂/聚丙烯酸钠的复配体系微极性的影响, 发现盐和醇对表面活性剂在聚电解质上形成类胶束和复合物的溶解都有一定的促进作用.     

NiO@SnO2@Zn2TiO4@TiO2同轴四层纳米电缆的制备、表征及形成机理研究

采用静电纺丝技术, 通过改进实验装置, 在最佳的纺丝条件下制备了[Ni(CH₃COO)₂＋PVP]@[SnCl₄＋PVP]@[Zn(CH₃COO)₂＋PVP]@[Ti(OC₄H₉)₄＋CH₃COOH＋PVP]前驱体复合电缆, 将其进行热处理, 制备出NiO@ SnO₂@Zn₂TiO₄@TiO₂同轴四层纳米电缆. 采用热重-差热(TG-DTA)、X射线衍射(XRD)、傅立叶变换红外光谱(FTIR)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)等分析技术对样品进行了表征. 结果表明, 所得产物为同轴四层纳米电缆, 芯层为NiO, 直径为35～55 nm|第二层为SnO₂, 厚度为30～50 nm|第三层为Zn₂TiO₄, 厚度为25～40 nm|壳层为TiO₂, 厚度为40～90 nm. 对同轴四层纳米电缆的形成机理进行了探讨.     

新型含硅表面活性剂的合成及性能研究

含有双胺基的三硅氧烷中的伯胺基与D-葡萄糖酸-δ-内酯进行酰胺化,仲胺基与低聚乙二醇甲醚缩水甘油醚、二缩水甘油醚进行烷基化,制备了新型含硅表面活性剂Me₃SiOSiMeR¹OSiMe₃ [R¹=(CH₂)₃NR²(CH₂)₂NHCO(CHOH)₄CH₂OH; R²=H, CH₂CH(OH)CH₂O(CH₂CH₂O)_xCH₃, x=1, 2, 3] (1a, 2a～2c)和(CH₂OCH₂)_y(Me₃SiOSiMeR³OSiMe₃)₂ [R³=(CH₂)₃NR⁴～(CH₂)₂NHCO(CHOH)₄CH₂OH; R⁴=CH₂CH(OH)CH₂OCH₂, y=0, 1, 2] (3a～3c).这些化合物的结构用¹H, ¹³C核磁共振仪和元素分析仪进行鉴定.研究了这些新型含硅表面活性剂的界面性能,在浓度分别为10^-4和10^-5 mol·L^-1时可以将水的表面张力降低至约21 mN·m^-1.     

水热法合成AgGd0.9Eu0.1(WO4)2及其发光性能

利用水热法制备了不同形貌的AgGd_0.9Eu_0.1(WO₄)₂ 红色发光材料, 通过X射线衍射(XRD)、扫描电镜(SEM)、X射线能谱分析(EDS)、透射电镜(TEM)及荧光光谱(PL)对不同条件下制备样品的物相、形貌和荧光性质进行了表征, 探讨了初始溶液的pH值和表面活性剂的种类对产物形貌和颗粒尺寸的影响. 结果表明: 本文所述条件下所得样品均属于单斜晶系|初始溶液的pH值和表面活性剂的种类对产物的形貌起关键作用. 通过调整初始溶液的pH值和表面活性剂的种类, 可以得到不同粒径的球形、棒状和空心球形颗粒|AgGd_0.9Eu_0.1(WO₄)₂的发射光谱表现为Eu^3＋离子的特征发射, 样品颗粒的形貌以及颗粒尺寸对发射光谱的强度有一定影响.     

以苯荒酸为配体的[Bu4N]2[W2Ag3S8(C6H5CSS)]钨银硫簇合物的合成和晶体结构

标题化合物由(C₆H₅CSS)^-(Bu₄N)⁺、AgNO₃和(NH₄)₂WS₄、Bu₄NBr反应制备,用X射线单晶衍射法测定其晶体结构。     

新型金属-双二硫杂戊烯(M-BDT)配合物的合成、表征及X射线的指标化

合成了4个新型NiBDT配位化合物,BDT为具有9个S原子的杂戊烯.元素分析、IR谱、UV谱确定这4个新配合物的化学式分别为[(CH₃)₄N]₂[Ni(C₅S₉)₂](1),[(C₂H₅)₄N]₂·[Ni(C₅S₉)₂](2),[(C₄H₉)₄N]₂[Ni(C₅S₉)₂](3),[(C₆H₅)(CH₃)₃N]₂[Ni(C₅S₉)₂](4).采用Ito法对配合物1的X射线粉末图进行了指标化,确定该晶体属单斜晶系,简单晶格,晶胞参数:a=0.680nm,b=0.714nm,c=2.302nm,γ=111.4°,Z=2.     

基于磺酰基杯[4]芳烃的Co16笼簇的合成、结构及电化学性质

以氯化钴、 对叔丁基磺酰杯[4]芳烃(H₄TC4A-SO₂)和非对称性3-(1H-四唑-5-基)苯甲酸(H₂L)为原料, 通过溶剂热法合成了一个具有四面体配位笼结构的16核化合物[Co₁₆(TC4A-SO₂)₄(OH)₄(L)₈]·[(C₈H₂₀N)(C₄H₁₂N)₂(C₂H₈N)]·solvent(Co₁₆-TC4A-SO₂). 采用X射线单晶衍射、 X射线粉末衍射、 热重分析、 红外光谱方法对配合物进行了表征. 将Co₁₆-TC4A-SO₂笼簇直接负载到碳纸上(Co₁₆-TC4A-SO₂/CP)用作工作电极, 其对析氧反应(OER)展现出较好的催化性能. 在1 mol/L KOH中, Co₁₆-TC4A-SO₂/CP在343.8 mV的过电位下达到10.0 mA/cm ²电流密度, Tafel斜率为79.31 mV/dec, 并且在20.0 mA/cm ²电流密度下表现出长达48 h的催化稳定性.     

系列Sm3+配合物的合成、结构及光物理性能

采用水热方法合成了4种Sm³⁺配合物, 即{[SmZn(2,5-pdc)₂(tp)_0.5(H₂O)]·2H₂O}_n(1), [Sm₂Zn₂(C₆H₅COO)₁₀(Imh)₂(H₂O)₂](2), {[Sm₂(NO₂C₆H₄COO)₆(H₂O)₄]·H₂O}_n(3)和{[SmN(CH₂COO)₃(H₂O)₂]·H₂O}_n(4)[2,5-pdc=2,5-吡啶二羧酸根, tp=对苯二甲酸根, C₆H₅COO=苯甲酸根, Imh=咪唑, NO₂C₆H₄COO=对硝基苯甲酸根, N(CH₂COO)₃=氨三乙酸根]. 通过单晶X射线衍射确定了其晶体结构. 在室温下测定了其红外光谱、 紫外-可见-近红外光谱以及在近红外区和可见区的发射光谱. 结果表明, 4种配合物在近红外区或可见区均出现Sm³⁺离子的特征发射. 这是形成配合物后, Zn-配体部分和配体对Sm³⁺离子发光的敏化作用所致. 此外, 讨论了不同有机配体或d过渡金属离子对Sm³⁺离子发光的影响, 并分析了配合物中Sm³⁺离子的近红外发射带位移、 劈裂和加宽的原因.     

纳米Al2O3粒子的制备

以异丙醇铝Al(Oprⁱ)₃(即Al(OCH(CH₃)₂)₃)为原料,用醇盐水解法制备纳米氧化铝粒子,比较系统地研究了制备条件(加水方式、反应物配比、浓度、溶剂等)对产物粒子颗粒大小的影响,采用TEM、X射线衍射等技术对所得产品性能进行了表征.实验结果表明,纳米Al₂O₃粒子分散性好,粒径在20-100nm之间,颗粒的形状和尺寸随反应条件的不同而变化.     

Mixing Behavior of Conventional and Gemini Cationic Surfactants

Micellization behavior of cationic monomeric surfactants, hexadecyltrimethylammonium bromide (CTAB), cetylpyridinium bromide (CPB), cetylpyridinium chloride (CPC), tetradecyltrimethylammonium bromide (TTAB), and dimeric (gemini) cationic surfactant pentamethylene‐1, 5‐bis(hexadecyldimethylammonium bromide) with formula C₁₆H₃₃(CH₃)₂N⁺(CH₂)₅N⁺(CH₃)₂C₁₆H₃₃ · 2Br^?, abbreviated as 16‐5‐16, in mixed states (binary) have been studied by conductivity. The micellar compositions, activities of the components, and their mutual interactions have been estimated from Rubingh's theory. The mixtures show nonideal behavior with favorable interactions.     

Synergism in cationic gemini – additive systems

A series of dicationic gemini surfactants with the general formula C₁₆H₃₃(CH₃)₂N⁺?(CH₂)_s?N⁺(CH₃)₂C₁₆H₃₃, 2Br^? (where s?=?4–6), designated as 16-s-16, were synthesised. Their interaction with organic additives: n-alcohols (C₃H₇OH, C₇H₁₅OH, C₈H₁₇OH) and the corresponding amines (C₃H₇NH₂, C₇H₁₅NH₂, C₈H₁₇NH₂) in the absence and presence of KNO₃ at 30°C was studied viscometrically to observe their effect on assembly formation and micellar transition. The simultaneous presence of KNO₃ and organics induced rich aggregates morphologies in the gemini micellar systems by giving high viscosity values. On comparing the behaviour of the gemini surfactant series for a given alkyl chain length of the organic additive, the spacer is found to markedly influence the behaviour; shorter the spacer, earlier the sphere-to-rod transition. In the case of the conventional surfactant, CTAB, the concentration of KNO₃ used with the geminis was insufficient to induce any transition.     

Catalytic role of gemini surfactant micelles in the ninhydrin-L-isoleucine reaction

Effect of dicationic gemini surfactants C₁₆H₃₃(CH₃)₂N⁺-(CH₂) _s -N⁺(CH₃)₂C₁₆H₃₃, 2Br⁻ (where s = 4, 5, 6) on the reaction of ninhydrin with L-isoleucine has been investigated spectrophotometrically as a function of [gemini], [L-isoleucine], [ninhydrin], and pH. The reaction follows first- and fractional-order kinetics, respectively, in [L-isoleucine] and [ninhydrin]. The gemini surfactant micellar media are found more effective for the reaction than their conventional monomeric counterpart CTAB. Furthermore, whereas typical rate constant (k _ψ) increase and leveling-off regions are observed with CTAB and geminis, the latter produce a third region of increasing k _ψ at concentrations ≥ 60 cmc’s. ¹H NMR studies reveal that this unusual third-region effect of the geminis is due to changes in their micellar morphologies. Quantitative kinetic analysis has been performed on the basis of modified pseudo-phase model.     

Micellization of monomeric and dimeric (gemini) surfactants in polar nonaqueous-water-mixed solvents

Dimeric or gemini surfactants are novel surfactants that are finding a great deal of discussion in the academic and industrial arena. They consist of two hydrophobic chains and two polar head groups covalently linked by a spacer. Data on critical micelle concentration (cmc) and degree of counterion dissociation (α) are reported on bis-cationic C₁₆H₃₃N⁺(CH₃)₂–(CH₂)_s–N⁺(CH₃)₂C₁₆H₃₃, 2Br⁻, referred to as 16-s-16, for spacer lengths s=4, 5, 6 in aqueous and in polar nonaqueous (1-propanol, 2-methoxyethanol or methyl cellosolve, dimethyl sulfoxide, acetonitrile)-water-mixed solvents. The behavior is compared with conventional monomeric surfactant cetyltrimethylammonium bromide (CTAB). Thermodynamic parameters are obtained from the temperature dependence of the cmc values. It is observed that micellization tendency of the surfactants decreases in the presence of polar nonaqueous solvents. However, detailed studies with dimethylsulfoxide (DMSO) show that the geminis nearly outclass the micellization-arresting property of this solvent. Also, within geminis, higher spacer length is found suitable for showing micellization even with high DMSO content (50% v/v). The implications of these results of gemini micellization may be useful in micellar catalysis in polar nonaqueous solvents.     

Effect of dicationic gemini surfactants 16–s‐16 (s = 4, 5, 6) on the ninhydrin‐dipeptide (glycyl‐tyrosine) reaction

The effect of dicationic gemini surfactants H₃₃C₁₆(CH₃)₂N⁺‐(CH₂)_s‐N⁺(CH₃)₂ C₁₆H₃₃, 2Br^? (s= 4, 5, 6) on the reaction of a dipeptide glycyl–tyrosine (Gly–Tyr) with ninhydrin has been studied spectrophotometrically at 70°C and pH 5.0. The reaction follows first‐ and fractional‐order kinetics, respectively, in [Gly–Tyr] and [ninhydrin]. The gemini surfactant micellar media are comparatively more effective than their single chain–single head counterpart cetyltrimethylammonium bromide (CTAB) micelles. Whereas typical rate constant (k_Ψ) increase and leveling‐off regions, just like CTAB, are observed with geminis, the latter produces a third region of increasing k_Ψ at higher concentrations. This subsequent increase is ascribed to the change in the micellar morphology of the geminis. The pseudophase model of micelles was used to quantitatively analyze the k_Ψ ? [gemini] data, wherein the micellar‐binding constants K_S for [Gly–Tyr] and K_N for ninhydrin were evaluated. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 44: 800–809, 2012     

Synthesis and Surface Properties of Novel Cationic Gemini Surfactants

A series of novel cationic gemini surfactants, p-[C _n H_2n+1N⁺(CH₃)₂CH₂CH(OH)CH₂O]₂C₆H₄·2Cl^? [A(n = 12), B(n = 14) and C(n = 16)], containing a spacer group with two flexible and hydrophilic groups (2-hydroxy-1,3-propylene) on both sides of a rigid and hydrophobic group (1,4-dioxyphenylene) has been synthesized by the reaction of hydroquinone diglycidyl ether with N,N-dimethylalkylamine and N,N-dimethylalkylamine hydrochloride. Their surface-active properties have been investigated by surface tension measurement. The critical micelle concentration (cmc) values of the synthesized cationic gemini surfactants are one order of magnitude lower than those of their corresponding monomeric surfactants (C _n H_2n + 1N⁺(CH₃)₃·Cl^?). Both the cmc and surface tension at the cmc (γ_cmc) of A are lower than those of p-[C₁₂H₂₅N⁺(CH₃)₂CH₂]₂C₆H₄·2Cl^? (D). The novel cationic gemini surfactants A and B also show good foaming properties.     

Micellization behavior of [C16-12-C16], 2Br gemini surfactant in binary aqueous-solvent mixtures

The micellization behavior of bis cationic gemini surfactant, N,N′-dihexadecyl-N,N,N′,N′-tetramethyl-1,12-dodecanediammonium dibromide [C₁₆H₃₃N⁺(CH₃)₂-(CH₂)₁₂-N⁺(CH₃)₂C₁₆H₃₃, 2Br⁻] has been studied in binary aqueous mixtures of dimethyl sulfoxide, methanol, 1,4-dioxane, glycerol and ethylene glycol by conductivity and surface tension measurements at 300 K. The critical micellar concentration, degree of micelle ionization (α), surface excess concentration (Г_max), minimum surface area per molecule of surfactant (A_min), Gibbs free energy of micellization (ΔG_m°), the surface pressure at cmc (π_cmc), and the Gibbs energy of adsorption (ΔG_ad°) of the gemini surfactant have also been determined. The cmc, α, A_min increases where as (ΔG_m°), Г_max, and π_cmc decreases with increasing volume percentage of the solvents in the solvent–water binary mixture. The interfacial properties of the gemini surfactant, solute–solute, solvent–solute interactions and the effectiveness of a surface-active molecule in binary solvent systems have been discussed.     

Quelques precisions sur les effets catalytiques des micelles cationiques hydroxylees

The alkaline hydrolysis of p-nitrophenyl acetate and of CH₃CO₂(CH₂)₂N⁺(CH₃)₂C₁₆H₃₃, Br^? was studied in the presence of micelles C₁₆H₃₃N⁺(CH₃)₂CH₂CH₂OH, Br^? and CTAB, C₁₆H₃₃N⁺(CH₃)₃,Br^?. A pathway involving an intermediate is suggested for the hydrolysis of the ester. Hydrolysis rate of the intermediate in the presence of micelles is the same as hydrolysis rate for the ester in the absence of micelles. Consequently, hydrolysis of p-nitrophenyl acetate is not catalysed by one type of micelle, while it is enhanced by another type of micelle.     

Micellization and Thermodynamic Parameters of Butanediyl-1,4-bis(tetradecyldimethylammonium Bromide) Gemini Surfactant at Different Temperatures: Effect of the Addition of 2-Methoxyethanol

The effect of the addition of 2-methoxyethanol on the critical micelle concentration (cmc) and on the degree of counterion dissociation (??) of butanediyl-1,4-bis(tetradecyldimethylammonium bromide) gemini surfactant, [C₁₄H₂₉N⁺(CH₃)₂?C(CH₂)₄?CN⁺(CH₃)₂C₁₄H₂₉,2Br^?] (referred as 14?C4?C14,2Br^?), has been studied by varying the compositions of the 2-methoxyethanol + water mixed solvent media (0 to 50?%). To determine various thermodynamic parameters of micellization, on the basis of the mass?Caction model for micelle formation, the experiments were performed at selected compositions of the mixed solvent at four temperatures ranging between 25?°C and 50?°C. Furthermore, the air/bulk surface tensions of the pure and mixed media were determined, and a successful attempt was made to correlate the cohesive energy density described through the Gordon parameter with the values of Gibbs energy of micellization.