单分散聚苯乙烯微球的表面皱纹化

首先制备了不同粒径的未交联的单分散聚苯乙烯(PS)微球;而后通过离子溅射技术在PS微球表面沉积了一层均匀光滑的铂(Pt)壳层,得到了PS-Pt核壳结构的复合微球;最后借用溶剂溶胀法诱导微球表面起皱的发生,从而制备了表面带有皱纹微结构形貌的PS微球.系统考察了微球表面Pt层厚度(t)、微球粒径(D)、溶剂组成(即溶胀度)等因素对球面起皱和皱纹形貌的影响,获得了球面皱纹周期与Pt层厚度的指数关系;结合理论分析了其起皱行为,实验结果与理论分析相吻合.此外,将表面起皱与表面等离子体刻蚀技术相结合,实现了表面带有纳米点状凸起与皱纹复合微结构形貌的PS微球的可控制备.     

Functionalized Polystyrene Nanoparticles Trigger Human Dendritic Cell Maturation Resulting in Enhanced CD4+ T Cell Activation

Nanoparticles (NP) represent a promising tool for biomedical applications. Here, sulfonate‐ and phosphonate‐functionalized polystyrene NP are analyzed for their interaction with human monocyte‐derived dendritic cells (DC). Immature dendritic cells (iDC) display a higher time‐ and dose‐dependent uptake of functionalized polystyrene NP compared to mature dendritic cells (mDC). Notably, NP induce an enhanced maturation of iDC but not of mDC (upregulation of stimulatory molecules and cytokines). NP‐triggered maturation results in a significantly enhanced T cell stimulatory capacity (increased CD4⁺ T cell proliferation and IFN‐γ production), indicating a shift to a pronounced Th1 response. Immunomodulatory properties of NP may be a useful strategy for strengthening the efficacy of NP‐based approaches in immunotherapy.

     

制备氯甲基化聚苯乙烯交联微球的新方法

使用Lewis酸催化剂, 用自制的氯甲基化试剂1,4-二氯甲氧基丁烷(BCMB), 在室温下对聚苯乙烯交联微球(白球)进行氯甲基化反应, 制得了氯含量接近17%的氯甲基化聚苯乙烯交联微球(氯球); 通过红外光谱法与佛尔哈德分析法表征了产物的化学结构与组成; 考察了各种因素对氯甲基化反应过程的影响规律. 结果表明, 各种因素对白球氯甲基化过程的影响表现在两个方面: (1) 影响白球的氯甲基化程度; (2) 抑制或促进分子链之间通过Friedel-Crafts反应进一步交联, 影响微球的强度.     

通过简单方法合成先驱体并利用电纺法制备BCN微米空心球

以三氯硼吖嗪(B3N3H3Cl3)和苯胺在N-甲基吡咯烷酮(NMP)溶剂中合成的聚合物为电纺液,由改进的电纺设备制备具有六方结构的BCN微米球。通过控制纺丝电压来控制BCN球体的直径。对其进行元素分析,并通过扫描电子显微镜,能量色散谱,X射线衍射和X射线光电子能谱进行表征。结果表明BCN微米空心球表面微凹,直径在10~30μm之间。硼碳氮间的比例约为1∶1.12∶0.94。     

Preparation and Characterization of Insulin-Loaded Lipid-Based Microspheres Generated by Electrospray

Electrospray has been recognized as an efficient technique for the fabrication of polymer micro and nanosystems and recently it was applied to lipids. The objective of this study was to assess the potential of electrospray for the encapsulation of insulin into lipid particles. Spherical particles of about 1 µm were obtained jetting a propanolic solution of palmitic or stearic acid and ethylcellulose or Pluronic F127 in a 10:1 or 20:1 (w/w) ratio under an electric field of 30 kV. Insulin was entrapped into the particles with high encapsulation efficiency by the formation of an ion-pair with sodium dodecyl sulphate. Far-ultraviolet circular dichroism spectroscopy indicated that electrospray did not modify the secondary structure of insulin. An in vitro prolonged release over 24 hours was observed after an initial burst effect. This study demonstrates that electrospray represents a viable new alternative for preparing in a single step peptide-protein loaded lipid based microspheres directly in powder form.     

受限空间内聚苯乙烯微粒的制备

以(N,N-二甲氨基-4-吡啶)五氰合铁(II)封端的聚氧丙烯聚氧乙烯共聚物(EPE-Fe)与苯乙烯在水中自组装形成纳米体系(EPE-Fe-St), 在纳米尺度受限空间内进行了苯乙烯自由基聚合, 制备了聚苯乙烯微球(EPE-Fe-PS). 用Fe³⁺对自组装体系的纳米球壳进行固化后形成Fe-EPE-Fe-St 体系, 聚合后也制备了聚苯乙烯微球(Fe-EPE-Fe-PS). 研究结果表明,制备了粒径为60～200 nm 的不同粒径单分散聚苯乙烯微球, 聚合温度对纳米Fe-EPE-Fe-St 体系粒径影响较小, 而对EPE-Fe-St 体系较大. 在受限空间内苯乙烯的自由基聚合可得到数均分子量超过70 万的聚苯乙烯; 自组装体系中引发剂量增多使聚苯乙烯分子量下降, 聚合温度上升也使分子量下降, 而增加自组装的EPE-Fe 用量可增加聚苯乙烯的分子量. 两种受限条件下的聚苯乙烯微球的玻璃化转变温度(T_g)在90～135 ℃之间, 纳米反应器壳层的硬化提高了聚苯乙烯微球的T_g.     

分散聚合法制备单分散交联聚苯乙烯微球

以苯乙烯为单体、二乙烯基苯为交联剂,通过优化反应条件,制备了平均粒径为3.28～9.04 μm的单分散聚苯乙烯微球和平均粒径为6.60 μm的单分散交联聚苯乙烯微球.探讨了单体浓度、引发剂含量、分散稳定剂用量对微球粒径和分散性的影响.热稳定性分析表明:交联聚苯乙烯微球耐热性明显优于线性聚苯乙烯.     

分散聚合法制备单分散聚苯乙烯微球

以苯乙烯为单体,偶氮二异丁腈为引发剂,聚乙烯吡咯烷酮为分散稳定剂,在乙醇/水的极性反应体系中,使用分散聚合法制备了聚苯乙烯(PS)微球。研究了制备工艺对微球分子量等远程结构参数的影响。研究结果表明:在适合微球形成的单体用量、引发剂和分散稳定剂的浓度、反应温度、时间和乙醇/水的比例等参数下,克服了以往存在的粒径不均匀、分子量较低、微球表面圆整光洁度较低和产率偏低等主要问题,制备了粒径在1.5~3μm之间、粒径分布1.05~1.08、分子量80×104左右、最高得率达97%、球体表面光洁、球形对称均匀且相互不粘连的单分散PS微球。     

Synthesis of Polystyrene and Polystyrene/Poly(methyl methacrylate) Nanoparticles

Summary: Polystyrene nanosize particles have been synthesized by a differential microemulsion polymerization process involving the use of a small amount of poly(methyl methacrylate) as the seeds. Sodium dodecyl sulfate and ammonium persulfate were used as the surfactant and initiator, respectively. The effects of various reaction conditions on the particle size have been investigated. Particle sizes of less than 20 nm have been achieved at milder conditions than those previously reported in the literature.

An HRTEM image of PS/PMMA nanoparticles.     

Fluorescent Determination of Mercury(II) Using Rhodamine B Immobilized on Polystyrene Microspheres

A novel microsphere-based fluorescent sensor 1 for determination of Hg(II) in food samples has been successfully synthesized and its fluorescent sensing properties were investigated in detail. Polystyrene microsphere was innovatively surface modified by a rhodamine derivative; therefore sensor 1 was a fluorescent sensor with high polymer material properties of polystyrene and the optical properties of a fluorescent probe. Sensor 1 displayed high selectivity, good anti-interference performance, and instantaneous response to Hg(II). The fluorescence intensity of sensor 1 showed a linear response to Hg(II) in the concentration range of 0?µM to 8?µM with a detection limit of 0.439?µM. The most valuable advantage was that sensor 1 was recyclable and environmentally-friendly. This proposed sensor 1 was applied to monitor the content of Hg(II) in real food samples, such as tap water, rice, and anglerfish. The recovery range of tap water was from 92.60 to 105.80%, the recovery range of rice was from 90.45 to 106.10%, and the recovery range of anglerfish was from 91.30 to 105.84%. The relative error was below 10% in spiked recovery studies, suggesting that fluorescent sensor 1 provides a simple, efficient, and promising method for determination of Hg(II) in complex matrices.     

Low‐Temperature Growth of Thick Polystyrene Brushes via ATRP

Summary: This contribution describes the graft polymerization of polystyrene (PS) by atom transfer radical polymerization at 50, 60, and 75 °C. Thick PS brushes were grown from initiator‐functionalized PGMA layers on silicon, and constant growth rates provide indirect evidence that the polymerizations were controlled.

Formation of polystyrene brushes at T < T_g by ATRP of styrene from α‐bromoester initiator‐functionalized poly(glycidyl methacrylate) layers.     

端环氧基聚苯乙烯低聚的物合成与表征

采用阴离子聚合法,以正丁基锂(n-BuLi)为引发剂、乙二醇二缩水甘油醚(EGDE)为封端剂,在常压惰性气体保护下引发苯乙烯(St)聚合,制得端环氧基聚苯乙烯低聚物(PS-ep)。采用GPCI、R和1H-NMR对PS-ep进行表征,并用盐酸-二氧六环银量法测定端环氧基含量。结果表明:以EGDE为封端剂可以使端环氧基摩尔分数(xep)达到0.80左右;升高封端反应温度和延长封端反应时间有利于提高端环氧基的摩尔分数;EGDE与n-BuLi的摩尔比以4∶1为宜。     

Preparation of Janus Graphene Oxide (GO) Nanosheets Based on Electrostatic Assembly of GO Nanosheets and Polystyrene Microspheres

A facile and versatile method for the synthesis of Janus graphene oxide (GO) nanosheets with different structures is reported. Based on electrostatic assembly, Janus GO nanosheets can be easily functionalized with a template polymer or be defunctionalized by altering the ionic strength. By using this approach, Janus GO nanosheets are prepared successfully with hydrophobic polystyrene chains on one side and hydrophilic poly(2‐(dimethylamino)ethyl methacrylate) chains on the other side.

     

含C60聚苯乙烯微球的制备及光电导性能研究

目前,多功能、高性能聚合物微球的合成及应用已成为研究热点.制备聚合物微球的方法有乳液聚合法、分散聚合法、无皂乳液聚合法、超微乳液聚合法和悬浮聚合法等.制备微米级微球通常采用乳液聚合法和分散聚合法.     

Controllable Preparation of Monodisperse Polystyrene Microspheres with Different Sizes by Dispersion Polymerization

Summary: Monodisperse polystyrene (PS) microspheres with different sizes were prepared by dispersion polymerization in dispersion media of ethanol/water and isopropayl alcohol/water, respectively. The effect of polarity of the dispersion medium, stabilizer and initiator concentration on the average sizes and size range were evaluated. The results show that monodisperse PS microspheres with different sizes could be prepared in dispersion media of ethanol and isopropyl alcohol/water when appropriate initiator and stabilizer concentrations were employed, and the latter is a more appropriate medium to prepare uniform PS microspheres. It was found that the microsphere sizes reduced with increasing water content in the dispersion medium. Furthermore, in isopropyl alcohol/water dispersions, the average sizes decreased with increasing stabilizer concentration.     

分散聚合制备聚苯乙烯/聚氧乙烯两亲磁性高分子微球

采用分散聚合法，以乙醇／水为介质，在Fe3O4磁流体存在下，通过苯乙烯与聚氧乙烯大分子单体共聚制备休磁性高分子微球。 研究了聚合条件对微球粒径的影响。通过改变聚合条件，可以得到平均粒径为5μm-100μm的两亲磁性高分子微球。     

单分散聚苯乙烯微球的制备及影响因素研究

以聚乙烯吡咯烷酮为分散剂，无水乙醇为反应介质，偶氮二异丁腈为引发剂，采用分散聚合工艺，通过优化反应条件，制备出了粒径为5μm单分散（分散系数≤5％）聚苯乙烯微球。所制备的聚苯乙烯微球标准偏差δ＝0．16μm，分散系数ε＝0．02，且具有良好的球形度，表面非常光滑，无破损，无缺损。对影响单分散聚苯乙烯微球的因素进行了研究，结果表明：随着分散稳定剂用量的增加，聚苯乙烯微球的粒径减小；随着单体和引发剂用量的增加，聚苯乙烯微球的粒径增大。分散稳定剂和单体用量是影响聚苯乙烯微球粒径分布的两个主要因素。     

Superhydrophobic Surfaces Produced by Carbon Nanotube Modified Polystyrene Composite Coating

The present work investigates the enhancement of water repellency on engineering materials surfaces using nanoscale roughness inherent in multi-walled carbon nanotubes (MWCNTs) together with a hydrophobic polystyrene coating via a simple spraying-based technique. The coatings show both a high contact angle and a small sliding angle for water droplets. The different surfaces obtained exhibit contact angles from 125° up to 153° depending on the preparation conditions. The observations of the topology by scanning electron microscopy reveal that the nanostructure created by the MWCNTs and the microstructure induced by the deposition of polystyrene particles forming a two-level structure that conceptually mimics the lotus leaf surface are necessary to create stable superhydrophobic surfaces.     

氯甲交联基聚苯乙烯微球的氨甲基化改性及其席夫碱型螯合树脂微球的制备

以氯甲基化交联聚苯乙烯(CMCPS)微球为出发物质,首先在催化剂KI存在下,与六次甲基四胺(HMTA)进行Delepine反应,制得氨基化改性的聚苯乙烯微球AMCPS;然后再使微球AMCPS与水杨醛(SA)发生Schiff碱反应,制备了Schiff碱型螯合树脂SACPS微球,采用红外光谱法表征了其化学结构。 重点研究了CMCPS微球氨基化改性Delepine反应的影响因素,探讨了反应机理。 研究结果表明,催化剂KI对CMCPS微球表面的苄氯基团与HMTA之间的Delepine反应,具有很强的催化作用;使用极性较强的溶剂DMSO及在较高的温度(80 ℃)下反应,氯甲基转变为氨甲基的效率高;Schiff碱型螯合树脂SACPS对Cu2+离子具有良好的螯合能力。     

窄分散大粒径交联聚苯乙烯功能微球的合成研究

用分散聚合法，以聚乙烯吡咯烷酮（PVP）为稳定剂，偶氮二异丁腈（AIBN）为引发剂，乙二醇二甲基双丙烯酸酯（EGDMA）为交联剂，一次加料法在醇水介质中制备数个微米交联聚苯乙烯（PS）微球。研究了苯乙烯（St)、丙烯酸（AA）、EGDMA的用量对粒子大小，粒径分布的影响。测量了微球表面羧基的含量。