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1.
Pickering乳液聚合制备核-壳结构PS-SiO2复合微球   总被引:1,自引:0,他引:1  
用二氯二甲基硅烷对纳米SiO2粒子进行疏水改性,当其表面Zeta电位由-54.8 mV变成-25.8 mV时,SiO2粒子就能在苯乙烯-水界面自组装,形成稳定的Pickering乳液,即以胶体粒子为乳化剂的乳液.利用Pickering乳液聚合制备了以聚苯乙烯(PS)为核、纳米SiO2为壳的PS-SiO2复合微球.用FT-IR、XPS、SEM、偏光显微镜等对复合微球进行了表征.结果表明:复合微球由聚苯乙烯和纳米二氧化硅粒子组成,二氧化硅粒子以单层、六方密排的方式分布在聚苯乙烯微球表面.  相似文献   

2.
以聚苯乙烯甲苯溶液为致孔剂,可以制得孔形较规整,孔径分布较均匀,耐高压(200kg/cm~2左右)的交联聚苯乙烯磺酸型离子交换树脂微球。本文对交联20%苯乙烯—二乙烯苯共聚微球,用不同致孔剂致孔后的性能及其磺化前后孔结构形态的变化,以及在色谱分析上的应用进行了探讨。  相似文献   

3.
本文利用聚苯乙烯微球为模板水热合成了聚苯乙烯/二氧化锰有机无机复合微球.复合微球核层为聚苯乙烯微球,壳层是由大量的二氧化锰纳米棒紧密堆积形成的.利用扫描电子显微镜及透射电子显微镜表征可以看出产物含有大量的复合微球,对于可能的反应机理进行了讨论.  相似文献   

4.
微球表面聚乙烯醇气体阻渗层的研制   总被引:5,自引:0,他引:5  
用多温区液熵炉在空心聚苯乙烯微球表面制备聚乙烯醇气体阻渗层,并对实验装置及部分工艺条件对实验结果的影响进行了讨论。  相似文献   

5.
王晓蜂  袁荞龙 《化学学报》2012,70(9):1047-1054
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(Tg)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Tg.  相似文献   

6.
化学镀法制备银壳聚苯乙烯微球   总被引:6,自引:0,他引:6  
采用一种新的化学镀法合成银壳包覆聚苯乙烯微球, 通过三乙醇胺和银离子络合来减小反应的氧化还原电位差, 降低银在改性聚苯乙烯微球表面的沉积速率. 采用TEM、XRD、UV 等测试手段对样品进行了分析和表征, 并考察了不同反应条件对实验结果的影响.实验表明, 该方法可在改性聚苯乙烯微球上包覆均匀的银层.  相似文献   

7.
“核-壳”结构微交联聚苯乙烯微粒的合成与表征   总被引:1,自引:0,他引:1  
本文用复合乳液聚合方法合成了粒径70—160nm的窄分散、微交联聚苯乙烯微粒,透射电子显微镜观测表明该微粒具有核-壳结构。用薄层色谱、透射电镜结合凝胶色谱、粘度等方法对该微粒进行了结构表征并探讨了影响微粒结构的主要因素。实验结果表明:双烯A用量为苯乙烯单体Ⅰ重量的1—4%,第一阶段聚合两小时后,滴加苯乙烯单体Ⅱ进行壳层聚合,合成的微粒含8.0—15.0%的线性聚苯乙烯,壳层主要由与核连接的聚苯乙烯链构成。  相似文献   

8.
在乙醇/氨水介质中,以分散法制备的聚苯乙烯微球为模板,通过乙烯基三乙氧基硅烷水解缩合反应在聚苯乙烯表面形成包覆层.然后将聚苯乙烯球核溶解而制备了乙烯基化二氧化硅空心微球.  相似文献   

9.
报道了通过分散聚合反应在碱式碳酸铜微球表面锚接聚苯乙烯纳米粒子, 以调节其亲水/亲油性的方法. 结果表明, 锚接的聚苯乙烯纳米粒子尺寸愈大, 所得的改性碱式碳酸铜微球疏水性愈强. 用对油和水润湿性适中的改性碱式碳酸铜微球为乳化剂, 能够制备出稳定的油包水型Pickering乳液. 改性碱式碳酸铜微球组装在Pickering乳液的分散相液滴表面, 形成一个固体壳层. 将Pickering 乳液的分散相水核凝胶化, 合成出分级结构琼脂糖凝胶微球.  相似文献   

10.
将聚苯乙烯改性制成磺化聚苯乙烯离聚体,溶解在甲苯/甲醇混合溶剂中,缓慢加水将聚苯乙烯乳化成稳定的水包油的水基微乳液。本文通过研究在乳化过程中体系粘度和导电性的变化,研究了聚苯乙烯离聚体溶液乳化过程的相反转机理和离子含量对乳化过程和相反转机理的影响。  相似文献   

11.
Microstructures of various polymers, such as polystyrene and polymethyl methacrylate, were fabricated with microcontact printing, directly using the corresponding dilute polymeric solutions as “inks”, whose concentrations were about 10 g/L. By repeatedly cross-stamping with the inks, multilayer quasi-three-dimensional polymeric microstructures could be obtained. Both optical photographs and SEM photos showed clear microstructures, which were nearly accurate replication of the original patterns in the PDMS stamps. Microlines of poly-bis-(p-toluene sulfonate)-2,4-hexadiyne-1,6-diol) (PTS) were also fabricated by first processed microcontact printing with solution of the corresponding monomer TS/acetone as ink, then followed with UV polymerization of the monomer micropatterns at solid state. Unlike small molecule processes, the molecules of polymeric inks did not self assembly on the surface of substrates. The formation of polymeric microstructures could be ascribed to the fact that, after volatilization of solvents, polymers tend to stick to the surface of glass substrate which has higher surface free energy (about 72 mN/m), but not to the surface of PDMS stamp which has lower surface free energy (about 20 mN/m). Also the microcontact printing process was studied with optical microscopy, and the main factor--volatilization time of solvent was discussed. The results showed that the volatilization time of solvent is very crucial to the process of polymeric microcontact printing, and with too longer or too shorter volatilization time, the obtained microstructures would become discontinuous or distorted, respectively. For example, with a polystyrene/chloroform solution as ink, the optimal volatilization time was about 15~20 s.  相似文献   

12.
微接触印刷法构造金属银的二维和准三维微图纹结构   总被引:4,自引:0,他引:4  
刘建平  何平笙 《物理化学学报》2003,19(12):1143-1145
以聚二甲基硅氧烷(PDMS)有机硅橡胶为弹性印章,以十八烷基三氯硅烷(OTS)正已烷溶液为“墨水”,用微接触印刷分别在普通盖玻片表面和直径为20 mm的试管外表面直接盖印,以及在直径为10 mm的玻璃棒表面进行滚动式微接触印刷盖印.将这些盖好印的基材放在化学镀银液中进行选择性镀银沉积,得到金属银在平面上的二维微结构和在曲面上的准三维微结构.这些微结构的显微照片显示,采用微接触印刷法制备的微图纹结构,图纹转移效率高,精细度很好,特别是微接触印刷操作方法灵活多变,适用于多种形态的表面,是一类实用的微制造方法.  相似文献   

13.
Conjugated polymers can be the alternatives to metals to manufacture the integrated circuit in nano/micro electromechanical systems (NEMS/ MEMS)[1], while patterning is the basis for such an application. It has been well known that the electro-deposition on a template[2—10] represents the simplest method to construct a patterned conducting polymer structure as compared with the conventional ap-proaches such as photolithography, e-beam writing, screen-printing, and ink-jet printing[11]. For…  相似文献   

14.
IntroductionThe preparationofmicro particlelatticewithstrictsizesandspacecontrolisanimportantproblemtobesolvedurgentlyinmanyhigh techfields .Tradi tionalmicro fabricationmethodisphotolithography ,butitisunabletoproduceanypatternsonacurvedsurfaceanddiffic…  相似文献   

15.
Micro-patterned films obtained from micro-contact printing (microCP) method are often challenged by site selectivity limitation. For applications site-selectivity requires improvements. In this paper a site-selective deposition of the rutile TiO2 thin films on patterned SnO2 film, which was formed on the patterned octadecyltrichlorosilane (OTS) SAMs through microCP is described. The depositions proceeded in an environmentally friendly aqueous solution (SnCl4 and peroxotitanium acidic solution) at a lower temperature (80 degrees C). It is shown that the OTS SAMs has a good selectivity deposition for SnO2 particles, which was mainly dominated by the heterogeneous nucleation mechanism. The SnO2 layer had a structure-directing effect for growth of the rutile TiO2, which was usually formed above 600 degrees C. The patterned films were characterized by a variety of techniques, including ellipsometry, optical microscopy, SEM, AFM, XPS, and DLS to determine the thicknesses, topologies, microstructures, chemical compositions of the films, particle sizes and zeta potentials of the titanium particles.  相似文献   

16.
Photoluminescent, porous silicon pixel arrays were fabricated via a Pt-promoted wet etching of p-type Si(100) using a 1:1:1 EtOH/HF/H2O2 solution. The pixels were fabricated with micrometer-scale design rules on a silicon substrate that had been modified with an octadecyltrichlorosilane (OTS) monolayer patterned using microcontact printing. The printed OTS layer serves as an orthogonal resist template for the deposition of a Pt(0) complex, which preferentially deposits metal species in areas not covered with OTS. The Pt centers generate a localized oxidative dissolution process that pits the Si in the Pt-coated regions, resulting in the formation of a porous silicon microstructure that luminesces around 580 nm upon illumination with a UV source. Scanning electron microscopy and fluorescence microscopy images of the fabricated porous silicon structures showed that features in the size range of approximately 10-150 microm, and possibly smaller, can be generated by this catalytically amplified soft lithographic patterning method. Importantly, the OTS acts as an etch mask, so that, even with significant hole transport, etching is confined to areas coated with the Pt(0) complex.  相似文献   

17.
利用去湿现象制备图案化的离子刻蚀聚合物保护层   总被引:3,自引:0,他引:3  
微米和纳米尺度的图案化表面的制备在微电子、光学、生物、化学和材料科学等领域具有重要的科学意义和应用价值 [1~ 3 ] .由于需要复杂昂贵的设备和苛刻的工作环境 ,光刻技术难以广泛应用于微电子以外的领域 ,因此 ,发展简单、便宜、适用于普通实验室 (尤其是化学实验室 )的表面图案化技术已成为一个涉及众多学科领域的课题 .在近年来不断涌现出来的物理、化学和生物的表面图案化技术 [4~ 6]中 ,最具代表性的是由 Whitesides等 [7]发明的以表面具有微观图案的聚二甲基硅氧烷 (PDMS)弹性体作为模具或印章的软光刻技术 .结合溶胶 -凝胶、…  相似文献   

18.
We describe a straightforward approach to the covalent immobilization of cytophilic proteins by microcontact printing, which can be used to pattern cells on substrates. Cytophilic proteins are printed in micropatterns on reactive self-assembled monolayers by using imine chemistry. An aldehyde-terminated monolayer on glass or on gold was obtained by the reaction between an amino-terminated monolayer and terephthaldialdehyde. The aldehyde monolayer was employed as a substrate for the direct microcontact printing of bioengineered, collagen-like proteins by using an oxidized poly(dimethylsiloxane) (PDMS) stamp. After immobilization of the proteins into adhesive "islands", the remaining areas were blocked with amino-poly(ethylene glycol), which forms a layer that is resistant to cell adhesion. Human malignant carcinoma (HeLa) cells were seeded and incubated onto the patterned substrate. It was found that these cells adhere to and spread selectively on the protein islands, and avoid the poly(ethylene glycol) (PEG) zones. These findings illustrate the importance of microcontact printing as a method for positioning proteins at surfaces and demonstrate the scope of controlled surface chemistry to direct cell adhesion.  相似文献   

19.
结合微接触印刷术和TiO2沉积成膜技术,在单晶硅表面成功地制备了具有微米级图案结构的TiO2薄膜,并利用XPS,SEM和AFM对其表面性质和结构进行了表征.该硅基图案化TiO2微结构在光电转化、微机电和光催化等领域中的应用具有重要意义.  相似文献   

20.
We report on a general lithography method for high-resolution biomolecule patterning with a bilayer resist system. Biomolecules are first immobilized on the surface of a substrate and covered by a release-and-protection interlayer of water-soluble polymer. Patterns can then be obtained by lithography with a spin-coated resist layer in a conventional way and transferred onto the substrate by reactive ion etching. Afterward, the resist layer is removed by dissolution in water. To demonstrate a high-resolution patterning, soft UV nanoimprint lithography has been used to produce high-density dot arrays of poly-(L-lysine) molecules on a glass substrate. Both fluorescence images and cell proliferation behaviors on such a patterned substrate have shown evidence of improved stability of biomolecule immobilization comparing to that obtained by microcontact printing techniques.  相似文献   

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