F127反相微乳液中纳米AgCl粒子的可控合成和AgCl/F127-PMMA有机/无机杂化膜的研究

在大分子F127为表面活性剂的反相微乳液体系中,合成AgCl纳米粒子。然后通过聚合制备AgCl/F127-PMMA有机/无机杂化膜,用于苯/环己烷混合物的渗透汽化分离。利用电导率仪、紫外可见光谱及透射电镜研究微乳液的增溶水量(ω)对微乳液结构、胶束中AgCl粒子的生成和形貌的影响。结果表明:合成的AgCl粒子粒径小于10 nm;增加微乳液的ω,生成的AgCl粒子变大。聚合后制备的AgCl/F127-PMMA有机/无机杂化膜中,AgCl粒子能保持较好的分散性。50wt%苯/环己烷混合物的渗透汽化结果表明,在合适的ω下,所制备的AgCl/F127-PMMA有机/无机杂化膜能克服常规高分子膜的trade-off现象,表现出较好的分离性能。     

离子液体微乳液合成纳米AgCl及AgCl/poly(MMA-co-St)杂化膜性能调控

在以离子液体氯化-1-十二烷基甲基咪唑(C12mimCl)为表面活性剂,甲基丙烯酸甲酯(MMA)与苯乙烯(St)混合物为油相介质的反相微乳液中合成AgCl纳米粒子,进而采用微乳液原位聚合法制备AgCl/poly(MMA-co-St)杂化膜。通过紫外可见光谱和透射电镜分析了微乳液组成(油相介质组成和增容水量ω)对纳米AgCl粒子形貌的影响。结合扫描电镜和苯、环已烷的溶胀实验探讨了微乳液组成对杂化膜性能的调控作用。结果发现,微乳液油相介质中St/MMA体积比增大有利于在微乳液和杂化膜中获得更多纳米AgCl粒子,增加了杂化膜的苯平衡溶胀吸附量(A∞,b)与苯/环已烷的平衡溶胀吸附选择性(αs,b/c)。在St/MMA体积比为1∶3时杂化膜的A∞,b和αs,b/c分别达到330 mg·g-1和19.21;但过多苯乙烯加入油相介质,其苯环中π键会破坏水核中AgCl粒子的稳定性而引起粒子团聚,从而降低了杂化膜的A∞,b和αs,b/c。反相微乳液中合成的纳米AgCl粒子量随ω增大而增多、粒径增大,杂化膜的A∞,b和αs,b/c随ω的增加而增大。但过高的ω导致微乳液中出现AgCl大粒子,从而引起杂化膜的A∞,b和αs,b/c下降。     

离子液体微乳液合成纳米AgCl及AgCl/poly(MMA-co-St)杂化膜性能调控

在以离子液体氯化-1-十二烷基甲基咪唑(C₁₂mimCl)为表面活性剂,甲基丙烯酸甲酯(MMA)与苯乙烯(St)混合物为油相介质的反相微乳液中合成AgCl纳米粒子,进而采用微乳液原位聚合法制备AgCl/poly(MMA-co-St)杂化膜。通过紫外可见光谱和透射电镜分析了微乳液组成(油相介质组成和增容水量ω)对纳米AgCl粒子形貌的影响。结合扫描电镜和苯、环已烷的溶胀实验探讨了微乳液组成对杂化膜性能的调控作用。结果发现,微乳液油相介质中St/MMA体积比增大有利于在微乳液和杂化膜中获得更多纳米AgCl粒子,增加了杂化膜的苯平衡溶胀吸附量(A_∞,b)与苯/环已烷的平衡溶胀吸附选择性(α_s,b/c)。在St/MMA体积比为1：3时杂化膜的A_∞,b和α_s,b/c分别达到330mg·g^-1和19.21;但过多苯乙烯加入油相介质,其苯环中π键会破坏水核中AgCl粒子的稳定性而引起粒子团聚,从而降低了杂化膜的A_∞,b和α_s,b/c。反相微乳液中合成的纳米AgCl粒子量随ω增大而增多、粒径增大,杂化膜的A_∞,b和α_s,b/c随ω的增加而增大。但过高的ω导致微乳液中出现AgCl大粒子,从而引起杂化膜的A_∞,b和α_s,b/c下降。     

反相微乳液中AgCl纳米粒子的可控合成与AgCl/GMA-MMA-AMPS共聚物有机-无机杂化膜的研究

以2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为表面活性剂,在甲基丙烯酸缩水甘油酯(GMA)和甲基丙烯酸甲酯(MMA)混合物为油相的反相微乳液体系中合成了AgCl纳米粒子,然后通过微乳液聚合制备了AgCl/GMA-MMA-AMPS共聚物有机-无机杂化膜,并用于苯/环己烷混合物的渗透气化分离.利用紫外-可见光谱及透射电子显...     

微乳液聚合耦合共混法构建聚偏氟乙烯共混杂化膜

以苯乙烯和甲基丙烯酸甲酯混合物作为油相, 采用反相微乳液法制备了AgCl纳米粒子; 通过微乳液原位聚合油相单体得到包含AgCl纳米粒子的聚合乳液; 将聚合乳液与聚偏氟乙烯(PVDF)通过共混法构建了包含AgCl纳米粒子的PVDF共混杂化膜. 紫外-可见光谱、 透射电子显微镜(TEM)及扫描电子显微镜(SEM)等表征结果和超滤实验结果表明, 聚合乳液加入的同时引入了亲水性聚合物和表面亲水的AgCl纳米粒子, 不仅改善了PVDF共混杂化膜的孔隙率和平均孔径, 还显著增强了PVDF共混杂化膜的极性和亲水性, 最终提升了膜的水通量和抗污染性能; 过量聚合乳液加入后不能与PVDF材料均匀共混, 而且AgCl纳米粒子也会在膜中形成团聚物堵塞膜孔隙, 从而削弱了膜的水通量和抗污染性能.     

苯在Pluronic F127和P123胶束水溶液中的增溶动力学

发展了不分离胶束的增溶动力学数据分析模型,以此考察苯在F127和P123胶束水溶液中的增溶动力学行为.实验发现,这二种胶束增溶苯的速度较快,温度升高进一步促进了增溶.     

17R4/F127混合水溶液的凝胶结构

结合流变学频率扫描和同步辐射小角X射线散射(SAXS), 研究了17R4(PO₁₄-EO₂₄-PO₁₄)含量和温度对17R4/F127(EO₉₉-PO₆₅-EO₉₉)混合水溶液凝胶结构的影响. 结果表明, 溶胶、 软凝胶和硬凝胶分别对应无序结构、 无序与立方相共存结构以及立方相结构. 对于F127水溶液体系, 可以将F127形成的胶束看作硬球, 随着温度的升高, 胶束的硬球半径和胶束中F127链的聚集数随之减小, 这是因为17R4在较低温度下很难形成胶束, 当温度升高时, 17R4链参与胶束的形成, 从而使胶束数目增加, 因此每个胶束中的F127链数也随之减小. 当17R4含量较高时, 胶束外壳中F127部分的PEO链段数随着温度升高而减小, 胶束外壳变得更软, 因此, 当17R4/F127摩尔比为2: 1时, 混合溶液在高温下呈现面心立方(fcc)到体心立方(bcc)的结构转变.     

含叶酸功能端基Pluronic F127的合成及其在水中的形态

通过一系列反应将三嵌段共聚物Pluronic F127的端羟基转变为氨基。利用氨基化F127大单体,最终成功的将生物活性大分子叶酸接到了F127端基上(F127-Folate) 作为靶向配体。利用1H-NMR对嵌段共聚物的结构进行了表征。用透析法制备胶束溶液,利用TEM研究了F127-Folate在水溶液中的自组装形态,结果表明F127-Folate正在水溶液中自组装形成纳米胶束。     

Ag/AgCl/GO可见光催化剂的制备及其性能

采用微乳液法成功制备了AgCl/GO复合可见光催化剂,利用XRD、TEM、FT-IR、UV-vis对复合光催化剂进行了表征.以甲基橙为目标污染物,考察AgCl/GO可见光催化降解活性.研究结果显示AgCl粒子实际上是以Ag/AgCl纳米结构形式较好地负载在石墨烯表面上.在甲基橙为20 mg·L~(-1),催化剂为0.05g的条件下,可见光照射100min后甲基橙的降解率达到91%以上.     

Pluronic嵌段共聚物F127胶团对布洛芬的增溶(英文)

研究了PluronicF127胶团溶液对药物布洛芬(IBU)的增溶作用.通过芘探针荧光法测定了不同温度下F127在水溶液和0.01mo·lL-1pH7.4磷酸盐缓冲生理(PBS)溶液中的临界胶束浓度(cmc),采用高效液相色谱(HPLC)测定了F127溶液中布洛芬的溶解度,并依据公式计算了增溶参数(摩尔增溶量c和胶团-水分配系数K),考察了温度、溶剂和F68的加入对F127胶团化行为及其对布洛芬增溶作用的影响.结果表明:布洛芬的溶解度随F127质量分数的提高线性增加;随着温度升高,cmc急剧下降,胶团内核的疏水性增强,χ和K稍有增大;与水溶液相比,在PBS溶液中cmc减小,χ几乎不变,K显著降低;F68的加入对F127胶团的性质几乎无影响,对增溶的影响也不明显.对增溶参数的分析表明,K反映的是药物布洛芬的性质,χ则可反映嵌段共聚物F127的溶解效能,并证实了布洛芬是通过F127胶团的内核和栅栏层而实现增溶的.     

核-壳结构的氯化银/聚丙烯酰胺复合纳米粒子的制备与表征

用反相微乳液作为模板制备了核-壳结构的氯化锯／聚丙烯酰胺(AgCI／PAM)复合纳米粒子。透射电镜(TEM)证实复合粒子为核-壳结构，平均直径约100nm。扫描电子显微镜(SEM)和X射线衍射分析显示，平均粒径约50nm的AgCl均匀分散在聚合物中。FTIR谱图表明：AgO与PAM之间存在较强的相互作用。用能级探洲光谱(Energy Detected Spectrum，EDS)和润湿分散实验比较了不同方法改性的复合粒子的表面结构与润湿性能。     

Photogeneration of Silver Nanoparticle Facilitated by Pluronic F127 Surfactant in Ethanolic Solution

In the present study, the photo-generation of silver nanoparticles in ethanolic solution and in the presence of F127 block copolymer using UV irradiation have been investigated. The aim of the present study is preparing the green, facile and much faster method than previous studies. The kinetics of silver nanoparticles formation has been investigated by using UV-vis spectroscopy. The two-dimensioanl map technique has been used to estimate the switching time between the nucleation and growth of Ag nanoparticles. The results show that the dispersed Ag nanoparticle in ethanol can be formed by high intensity ultraviolet exposure within few minutes.     

Sonochemical synthesis of Ag/AgCl nanocubes and their efficient visible-light-driven photocatalytic performance

A novel one-step sonochemical approach to synthesize a plasmonic photocatalyst of AgCl nanocubes (ca. 115 nm in edge length) with a small amount of Ag metal species is presented. The nanoscale Ag/AgCl hybrid photocatalysts with cubic morphology are readily formed under ambient ultrasonic conditions and neither external heat treatment nor reducing agents are required. The size of the Ag/AgCl photocatalysts could be controlled by changing the concentrations of Ag(+) ions and polyvinylpyrrolidone molecules in precursor solutions. The compositions, microstructures, influencing factors, and possible growth mechanism of the Ag/AgCl hybrid nanocubes were systematically investigated. The Ag/AgCl photocatalysts show excellent photocatalytic performance for degradation of various dye molecules under visible light.     

Sonochemical Synthesis of Ag/AgCl Nanocubes and Their Efficient Visible‐Light‐Driven Photocatalytic Performance

A novel one‐step sonochemical approach to synthesize a plasmonic photocatalyst of AgCl nanocubes (ca. 115 nm in edge length) with a small amount of Ag metal species is presented. The nanoscale Ag/AgCl hybrid photocatalysts with cubic morphology are readily formed under ambient ultrasonic conditions and neither external heat treatment nor reducing agents are required. The size of the Ag/AgCl photocatalysts could be controlled by changing the concentrations of Ag⁺ ions and polyvinylpyrrolidone molecules in precursor solutions. The compositions, microstructures, influencing factors, and possible growth mechanism of the Ag/AgCl hybrid nanocubes were systematically investigated. The Ag/AgCl photocatalysts show excellent photocatalytic performance for degradation of various dye molecules under visible light.     

A novel method for the preparation of silver chloride nanoparticles starting from their solid powder using microemulsions

A novel method of preparing AgCl nanoparticles by mixing AgCl powder and a microemulsion consisting of dioctyldimethylammonium chloride/n-decanol/water/isooctane is introduced. This new method was discovered during the preparation of AgCl nanoparticles in single microemulsions by direct reaction with the dioctyldimethylammonium chloride surfactant counterion. The effect of the following variables on the concentration of the colloidal AgCl nanoparticles (the nanoparticle uptake) and the particle size were studied: (1) operating variables, including mixing and temperature; and (2) microemulsion variables, including surfactant and cosurfactant concentration, and water to surfactant mole ratio. Manipulating these variables provides an insight into the role of the surfactant surface layer rigidity on the phenomenon. The results were explained by the effect of these variables on reaction rates and the colloidal nanoparticle stability. Mixing had a significant effect on the nanoparticle uptake. At 300 rpm an equilibrium AgCl nanoparticle uptake was achieved in about 1 h, while without mixing only 5% of the equilibrium value was reached even after 24 h. An optimum temperature was found for which a maximum nanoparticle uptake was obtained. At higher temperatures, the nanoparticle uptake declined. The nanoparticle uptake increased linearly with the surfactant concentration, and the particle size increased as well. A monotonic decrease in the nanoparticle uptake accompanied by an increase in the particle size was observed when increasing n-decanol concentration or the water to surfactant mole ratio.     

Bifunctional AgCl/Ag composites for SERS monitoring and low temperature visible light photocatalysis degradation of pollutant

With the assistance of Polyvinylpyrrolidone (PVP), AgCl/Ag composites were fabricated in N, N-Dimethylformamide (DMF) solvent via a photoactivated route. The size of AgCl particles was in the range of 500 nm to 1 μm and the Ag particle's diameter was about 10–20 nm. Different from those core–shell structures reported before, the Ag nanoparticles were dispersed uniformly both on the surface and in the body of AgCl particles. The generation of such kind of composites was resulted from the reducing ability of DMF and light irradiation during the formation of AgCl particles. The as-obtained AgCl/Ag composites presented great activity for both surface-enhanced Raman scattering (SERS) detection and visible light photocatalytic degradation of organic dyes. Additionally, the AgCl/Ag composites could maintain high photocatalytic activity even though the ambient temperature was as low as 15 °C and recycle photocatalysis experiments indicated that the photocatalyst exhibited higher stability. Such kind of AgCl/Ag composites holds great potential for environmental monitoring devices and pollutant treatments.     

Synthesis and photocatalytic performance of Ag/AgCl/ZnO tetrapod composites

Ag/AgCl is a visible-light plasmonic photocatalyst that has attracted considerable attention because of its high visible-light absorption and activity owing to the surface plasmon resonance of noble-metal nanoparticles. In this study, Ag/AgCl/ZnO tetrapod composite was prepared by introducing ZnO tetrapods into Ag/AgCl prepared by a polydopamine reduction route. Ag/AgCl was densely deposited on the three-dimensional support framework provided by the ZnO tetrapods. The framework possessed a certain degree of porosity, thereby improving the specific surface area of the Ag/AgCl/ZnO composite. The interaction of ZnO with Ag/AgCl further increased the separation and transfer of electron–hole pairs. The Ag/AgCl/ZnO composite showed excellent photocatalytic activity and good stability. Under xenon lamp irradiation for 20 min, degradation of rhodamine B reached 90%. After four recycling tests, degradation remained stable without any sign of reduction. Ag/AgCl/ZnO tetrapod composite is shown to be a kind of green photocatalyst offering high activity, good stability, and recyclability.