山莓状Au-树脂微球的制备及SERS性能

采用抗坏血酸在室温下液相还原AuCl₄^--阴离子交换树脂微球, 同时实现Au微柱的形成及在树脂表面的阵列型组装, 低成本高通量地得到山莓状Au-树脂微球; 以苯硫酚为探针考察了山莓状Au-树脂微球用作表面增强拉曼散射(SERS)活性基底的性能, 结果表明, Au-树脂微球具有良好的Raman增强效应(增强因子EF达到10⁸～10⁹量级), 且有很高的重现性和稳定性, Raman信号强度和EF的相对标准偏差(RSD)为(35±5)%.     

甲基橙为光谱探针研究聚电解质与表面活性剂相互作用

聚电解质与两亲分子间相互作用近年备受关注^[1,2].其原因之一是这种作用与作为形成生物膜基础的类脂间的相互作用极其相似,并可看作细胞中蛋白质-核酸相互作用的一种模式^[3].对众多水溶性高分子尤其是聚电解质与表面活性剂间相互作用研究表明,这种作用不仅有重要的学术意义,而且在实际应用方面也非常重要,如应用于泥浆凝聚,油井采油以及膜分离技术^[4]等.     

分散共聚合制备PSt-AA-EGDMA功能性单分散微米级交联微球的研究

以苯乙烯(St)为主单体,丙烯酸(AA)为功能单体,乙二醇二甲基双丙烯酸酯(EGDMA)为交联单体,聚乙烯吡咯烷酮(PVP)为稳定剂,偶氮二异丁腈(AIBN)为引发剂,乙醇/水混合溶剂为分散介质,用分散聚合法一步合成了功能性单分散大粒径(10～20μm)交联聚苯乙烯微球.研究了PSt-AA-EGDMA三元分散共聚合体系的动力学,由转化率-时间关联得到动力学方程;R_p=k[I]^0.13([St]^1.87+[AA]^0.13+[EGDMA]^0.2)·(1+[PVP]^0.2)exp(-E/RT).详细讨论了AA,EGDMA,PVP的浓度和溶剂极性对羧基分布的影响,阐述了AA和EGDMA对粒子形态、粒径及粒径分布的影响.     

在线性或交联的聚氨酯粒子内原位还原制备纳米银粒子

纳米金属粒子有特异性质 ,可用作高效催化剂、非线性光学材料等 .为防止其聚集 ,不少研究者采用表面活性剂 [1]、配位体 [2 ]和高分子等以阻止纳米金属粒子的聚集 .近年来高分子金属复合纳米粒子引起人们广泛的兴趣 [3～ 9] .文献上大多采用线性或嵌段双亲高分子作纳米金属的分散稳定剂[6 ] 或在高分子粒子表面沉积纳米金属粒子[5] ,也有人采用多孔交联高分子微球的孔洞作为微反应器形成纳米金属粒子[7] .这些方法均不能有效地控制金属粒子的粒径 ,特别难以合成粒径小于 3 0 nm的银粒子 .本文首次报道了在常温处于粘弹态 ,线性或交联的高分…     

聚乙二醇接枝聚乳酸的自组装纳米微球的制备及性能

对制备的新型聚乙二醇(PEG)接枝聚乳酸(PLA)在水中的自组装性能进行研究, 探讨其作为纳米药物载体的可行性和稳定性. 目测法得到其溶解度为(2.16～4.32)×10^－2 mg•mL^－1; 荧光法得到聚合物的临界胶束浓度为1.12×10^－3 mg•mL^－1; 透射电子显微镜观察显示该聚合物在水中的自组装聚集体为纳米级球形; 动态激光光散射测试微球的粒径和Zeta电位发现, 在微球的制备过程中, 聚合物的亲/疏水性比例、水相介质及水溶液的pH值对它影响显著; 而制备后, 稀释和冷冻对它无显著影响, 改变微球的环境pH值至酸性, 出现聚集, 至碱性无影响. 研究结果显示, 该聚合物在水和磷酸钠盐缓冲液中可形成稳定的纳米微球, 通过微球的制备条件和存在环境可控制其粒径和Zeta电位, 因此根据应用需要, 通过控制其粒径和Zeta电位, 可能提高微球的在体血液循环时间并实现靶向缓释.     

掺杂态聚苯胺蜂窝状有序多孔薄膜的制备及形成机制的探讨

近年来,由于微米、亚微米及纳米级有序多孔结构薄膜可以用于催化、生物培养基材、分离或吸附介质、光子晶体等诸多方面从而引起了科学家们极大的研究兴趣^[1～6].微制作是使材料表面具有新性能的重要手段,激光刻蚀及其相关技术已经被应用于不同表面的微图案化和微器件的制作^[7],另外,还可通过自组装技术进行多孔薄膜的制备^[8,9].Francois等^[10]于1994年首次提出了水辅助方法(Water-A ssisted Fab-rication),即在高湿度的环境下,以冷凝水滴为模板,在固体基片上制备了孔径分布均一,排列紧密的蜂窝状有序多孔薄膜.继而人们对此方法做了进一步的研究,不仅突破了最初的聚苯乙烯及其共聚物体系^[10～13],而且使用双亲共聚物^[14]、聚离子复合物^[15]和TiO₂前驱体的混合物^[16]等成功地获得了蜂窝状有序多孔薄膜,同时系统地研究了成膜体系及成膜条件对形成蜂窝状有序多孔薄膜的影响,并对形成机制进行了探讨.聚苯胺是典型的导电高分子,有关聚苯胺有序多孔结构薄膜的研究已有报道^[17～19].本文采用水辅助方法,在高湿度环境下,使用4-十二烷基苯磺酸掺杂的聚苯胺(PANI-DBSA)为成膜材料,制备了双层蜂窝状有序多孔薄膜,并通过原子力显微镜(A FM)对薄膜的形貌和电学性质进行了表征.同时在已有成膜机制的基础上,提出了该双层蜂窝状有序多孔薄膜的形成机制.     

碳酸钙模板法制备高分子微球

模板法是一种制备粒径可控、形貌均一微球的有效途径。以球霰石形态存在的CaCO₃多孔微球具有生物相容、孔径均一,以及可在温和条件下分解等优点,适用于作为模板制备微球。本文在对CaCO₃模板进行简单介绍的基础上,从原料选取与应用角度综述了用CaCO₃模板法制备微球的研究进展。常用的装载CaCO₃多孔微球的方法有物理吸附、共沉淀和渗透法等,所用原料有天然高分子(如多糖、蛋白质、DNA)和合成高分子(如聚苯乙烯磺酸钠、聚乙烯醇)。利用CaCO₃模版制备的微球具有多孔洞或空心结构,尺寸形貌均一可控,特别适用于制药、药物递送、生物传感器及化学分析等领域。预计随着纳米技术的发展和生物医药领域的需求将推动CaCO₃模板法的研究,以期通过该方法制备出应用领域更加广泛的微球。     

空心玻璃微球附载TiO2光催化降解有机磷农药

有机磷农药废水的处理目前大多采用生化法,但是处理后的废水中有机磷的含量仍远远高于国家关于废水的排放标准。近年来,利用半导体粉末作为光催化剂降解有机污染物的研究已有许多报道^[1,2].文献[3-5]报道了利用光催化剂的悬浮体系降解有机磷化合物的研究,结果表明,有机磷在短时间内可被完全光催化降解至无机磷(PO₄^3-).但是由于半导体粉末甚细,采用悬浮体系既造成光催化剂的二次回收困难,又易造成浪费.本文在先前工作的基础上,将TiO₂附载在空心玻璃微球上形成TiO₂/beads光催化降解有机磷农药,探讨了多种因素对光催化降解的影响.     

一种以毛细作用和蒸发为驱动力的新型微泵的研制

关于微泵的研制起始于20世纪80年代^[1],现已研制开发出很多种类的微泵,如可以用多种驱动力驱动的机械微泵(压电驱动、静电驱动和热气动力驱动等)^[2]和以场感应流微泵为主的非机械微泵(包括电渗泵、磁液态动力泵和电液态动力泵等^[3]).机械微泵的制造工艺复杂,而且液流有脉动性;场感应流微泵的液流无脉动性,流速范围可在每分钟几纳升到每分钟几百微升之间变化,因此被微流控系统广泛采用,但这种微泵需要庞大的驱动器,使用不便.     

复合Fe2O3纳米粒子的高分子微球的结构表征

近年来，复合有机、无机粒子的高分子微球及其特殊性质越来越引起人们的兴趣与关注［1］．获得有机、无机复合微球的方法很多，如在无机粒子存在下的乳液或无皂乳液聚会[2，3]，通过可聚合的表面活性剂在粒子表面形成胶囊化层[4]以及共沉淀法等[5]．这些无机粒子包括氧化钛、氧化铁、氧化铝及氧化硅等．Haga等[6]增发现包覆在聚合物粒子中的CdS与其本体的光电性质不同；单分散的聚合物微球可以在基片上被组装成二维乃至三维有序的结构[7]．这为信息存储、立体印刷等领域提供了新途径．因此，将无机粒子与聚合物复合成为功能化粒子是一项有…     

Preparation of Monodispersed Polymer Microspheres by SPG Membrane Emulsification‐Solvent Evaporation Technology

The membrane emulsification coupled with solvent evaporation was adopted to prepare monodispersed polystyrene (PS) microspheres. Firstly, stable oil‐in‐water emulsion has been successfully obtained by pressing PS solution through SPG membrane into continuous phase at appropriate pressures. Then monodispersed PS microspheres with size of 2–20 µm were obtained following the removal of solvent. The size of the PS microspheres was strongly dependent on the mean pore size of SPG membrane and concentration of PS solution. Furthermore, the effect of emulsion stability, operation pressure and emulsifier on the size and size distribution of microspheres were systemically investigated. Finally, the surface character of PS microspheres was examined via SEM.     

单分散聚苯乙烯微球的制备及表征

应用膜乳化-液中干燥法成功制备出粒径为2～20μm的单分散聚苯乙烯(PS)微球.PS微球的粒径主要由膜孔径决定,其值约为膜孔径的2倍;PS溶液的浓度对其也有一定的影响.膜乳化过程中的压力对微球粒径的分散性有很大的影响,在一定压力范围内,粒径呈单分散.在分散相中加入致孔剂,制备出表面多孔的PS微球.采用复乳-液中干燥法制备出中空PS微球.     

用多孔玻璃膜管悬浮聚合法制备单分散性聚苯乙烯微球

Monodisperse polystyrene microspheres are prepared by shell porous glass(SPG)-suspension polymerization. The influences of SPG on size and size dispersity of the microspheres are investigated. The properties of the microspheres are studied by GPC, TEM and SEM. The results indicate that the polystyrene microspheres possess definite monodispersibity and their particle size is in the range of 5～12μm.     

Effect of polyethylene glycol on preparation of rifampicin-loaded PLGA microspheres with membrane emulsification technique

Monodisperse poly(lactide-co-glycolide) (PLGA) microspheres containing rifampicin (RFP), anti-tubercle drug, as hydrophobic model drug were prepared by solvent evaporation method with a membrane emulsification technique using Shirasu Porous Glass (SPG) membranes. Five kinds of rifampicin-loaded PLGA (RFP/PLGA) microspheres with different sizes were prepared by changing pore size of the membranes. Effect of polyethylene glycol (PEG) added to polyvinyl alcohol (PVA) solution (continuous phase) upon the monodispersity of microspheres was studied. PEG was used as a stabilizer for microspheres dispersing in PVA solution. The most suitable molecular weight of PEG as a stabilizer was 20,000. RFP/PLGA microspheres prepared with PEG20000 were apparently more uniform than those prepared without PEG. The yield of RFP/PLGA microspheres was 100%. The initial burst observed in the release of RFP from RFP/PLGA microspheres was suppressed by the addition of PEG.     

A Comparison of Membrane Emulsification Obtained Using SPG (Shirasu Porous Glass) and PTFE [Poly(Tetrafluoroethylene)] Membranes

SPG (Shirasu porous glass) membrane emulsification used to prepare uniform polymeric microspheres is briefly reviewed, and the performance of a hydrophilically treated PTFE [poly(tetrafluoroethylerie)] membrane is described and compared with that of the SPG membrane. A mixture of styrene. divinyl benzene and hexadecane (HD) was extruded through the membranes and dispersed in an aqueous phase containing polyvinylalcohol (PVA) and sodium lauryl sulfate (SLS) as mixed stabilizers. A hvdrophilically treated PTFE membrane was used with a stainless steel mesh support so that the membrane would not expand to affect the pore size during the emulsification. The nominal pore size of the PTFE membrane was replaced with the calculated one using a theoretical expression derived from the force balance between the external pressure and the interfacial tension between oil and water phases. The emulsion droplets prepared with the PTFE membrane revealed a broader size distribution than those obtained with the SPG membrane, and the rate of emulsificaton was nearly same for both membranes. Droplet size control was readily possible. The performance was significantly affected by the adsorption behavior of the stabilizers on the membrane surfaces. The contact angle profile of oil droplets on the PTFE membrane implied that the hydrophilically treated PTFE membrane is still hydrophobic compared to the SPG membrane. This tendency was reflected by the dependence of the average droplet diameter (and coefficient of variation, CV) on the concentration and composition of mixed stabilizers.     

PLA/MSM缓释微球的制备及生物活性

采用膜乳化-液中干燥法制备出担载二甲基砜(MSM)的聚乳酸(PLA)微球(PLA/MSM), 并研究了膜孔径、 搅拌转速和MSM浓度对载药微球形貌、 尺寸、 载药量、 体外释放及细胞活性的影响; 采用场发射环境扫描电子显微镜(ESEM)观察微球形貌、 尺寸及分布, 用等离子体发射光谱(ICP-AES)法检测PLA/MSM微球载药量、 包封率及体外释放, 采用ESEM观察微球内部结构, 并通过体外细胞培养和噻唑蓝(MTT)法检测MC-3T3-E1细胞的增殖能力. 研究结果表明, 膜乳化法制备的载药微球规整, 呈典型的圆球状, 表面光滑, 内部有多孔结构. 当膜孔径为5.1 μm且搅拌转速为500 r/min时, PLA/MSM微球大小更为均一; 当体系中MSM质量分数为8.6%时, 载药量可达到77.43%. 随着膜孔径减小及药物浓度的增加, 体外释放速率加快, 但初期均无明显的突释现象, 约10 d后累积释放量达到89.2%. 细胞实验结果显示, 在膜孔径为5.1 μm且MSM质量分数为8.6%的条件下, 制备的载药微球在细胞培养7 d时表现出明显的促增殖作用.     

含VE微胶囊的制备及其控制释放性能研究

以天然维生素E（VE）为芯材，利用Shirasu porous glass (SPG) 膜乳化结合液中干燥法，制备了粒径单分散的聚苯乙烯（PS）微胶囊.微胶囊的粒径为膜孔径的4倍，粒径单分散系数CV小于0.2.考察了改变PS和VE的比例及微胶囊的粒径对控制释放性能的影响.     

膜乳化-溶剂挥发法制备表面羧基功能化苯乙烯-马来酸酐共聚物微球

以苯乙烯-马来酸酐共聚物(PSMA)为原料,利用膜乳化-溶剂挥发法,成功制备了表面光滑、尺寸均一的表面羧基功能化聚合物微球.研究表明:将膜乳化法和溶剂挥发法相结合,可以有效提高微球粒径的均一性,乳化剂种类及浓度、连续相流速、分散相中聚合物浓度等参数对微球粒径及粒径分布有显著影响.此外,利用盐酸使微球酸酐基团水解,可以得...     

Facile synthesis of hollow polymeric microparticles possessing various morphologies via seeded polymerization

In this paper, hollow poly(styrene-co-divinylbenzene-co-methacrylic acid) microparticles possessing various morphologies were synthesized by a combination of seeded polymerization and SPG membrane emulsification. Three families of polystyrene (PS) microspheres with various molecular weights but similar diameters were fabricated by SPG membrane emulsification. These PS microspheres were used as seeds to investigate the effect of their molecular weight on the phase separation between the PS seeds and microgel-like networks formed during seeded polymerization and on the morphologies of the resultant particles. Our study revealed that three resultant microparticles possessed diameters of ca. 10?μm and hollow cavities. The shell thickness of the particles became thinner as M _w increased from 3.5?×?10⁴ to 28.0?×?10⁴. The morphological evolution of the microparticles during seeded polymerization was monitored, and these results verified the influence of the molecular weight of the PS seeds on the phase separation behavior and hence the morphologies of the resultant particles.     

Study of SPG membrane emulsification processes for the preparation of monodisperse core-shell microcapsules

Experimental investigations on the Shirasu-porous-glass (SPG)-membrane emulsification processes for preparing monodisperse core-shell microcapsules with porous membranes were carried out systematically. The results showed that, to get monodisperse oil-in-water (O/W) emulsions by SPG membrane emulsification, it was more important to choose an anionic surfactant than to consider hydrophile-lipophile balance (HLB) matching. Increasing the viscosity of either the disperse phase or the continuous phase or decreasing the solubility of the disperse phase in the continuous phase could improve both the monodispersity and the stability of emulsions. With increasing monomer concentration inside the disperse phase, the monodispersity of emulsions became slightly worse and the mean diameter of emulsions gradually became smaller. Monodisperse monomer-containing emulsions were obtained when the SPG membrane pore size was larger than 1.0 micro m, and from these emulsions satisfactory monodisperse core-shell microcapsules with a porous membrane were prepared. On the other hand, when the SPG membrane pore size was smaller than 1.0 mciro m, no monodisperse emulsions were obtained because of the formation and chokage of solid monomer crystals in the pores or at the end of the pores of the SPG membrane. This was due to the remarkable solvation and diffusion of the solvent in water. With increasing the emulsification time the average emulsion diameter generally decreased, and the monodispersity of the emulsions gradually became worse.