新型核-壳结构丙烯酸酯乳胶涂料

采用无皂种子乳液聚合合成出聚甲基丙烯酸甲酯（ＰＭＭＡ）为核,聚丙烯酸正丁酯（Ｐｎ－ＢＡ）为壳的复合乳液,并以此乳液为基材配制出性能优良的建筑外用乳胶涂料。研究了单体配比、增稠剂用量、ｐＨ值等因素对涂料性能的影响。     

单体含量对核壳结构聚氨酯-聚丙烯酸酯乳液性能影响

以水性聚氨酯（PU）为种子乳液,以丙烯酸酯（PA）为聚合性单体,采用种子乳液聚合法合成核壳结构聚氨酯-聚丙烯酸酯乳液（PUA）。研究了单体含量对乳液及胶膜性能的影响。实验结果表明：随着乙烯基单体含量的增加,乳液颜色加深,稳定性下降,胶膜的断裂伸长率降低,硬度和耐水性增加。当乙烯基单体和PU百分比（M／P）为25％时,乳液的稳定性大于12个月,胶膜的断裂伸长率为498％,硬度为0．64,吸水性为22．8％。红外光谱分析表明合成了PUA。     

气流-静电纺丝法制备聚对苯二甲酸乙二酯纳米纤维

采用50%苯酚和50%1,1,2,2-四氯乙烷的混合溶液为溶剂,通过气流-静电纺丝法制备了聚对苯二甲酸乙二酯(PET)纳米纤维。利用扫描电镜(SEM),研究了聚合物分子质量、溶液浓度、电压、接收距离(喷丝孔到接收板的距离)对电纺纤维形态结构的影响。结果表明:随着聚合物分子质量和溶液浓度增加,纤维平均直径也随之增加;纤维平均直径随电压的增加而减小;随接收距离的增加,纤维平均直径先减小后增加。最佳工艺条件为:聚合物特性黏度为0.818 dL/g,溶液质量分数为15%,电压为32 kV,接收距离为23 cm,所得PET电纺纳米纤维平均直径为85 nm。     

皮革涂料用丙烯酸酯核-壳乳液的研制

采用种子乳液聚合法，以交联型软性聚合物为核，交联型硬性高聚物为壳，合成了具有优异耐寒性及高温抗回粘性聚合物。讨论了乳化剂种类及应用、核／壳比等对聚合物性能的影响。     

乳化剂对核／壳型丙烯酸酯乳液性能的影响

选用阴离子乳化剂和非离子乳化剂复合使用,研究了乳化剂的用量、乳化剂的配比以及加入方式对核／壳型丙烯酸酯乳液性能的影响。     

Fabrication of Multifunctional Composite Nanofibers by Green Electrospinning

The present work takes advantage of green electrospinning to create novel composite multifunctional nanofibers (NFs) bearing inorganic nanoparticles (NPs), more specifically quantum dots (QDs), cerium oxide nanoparticles (CeO₂ NPs) and iron oxide nanoparticles (Fe₃O₄ NPs). This is achieved by first encapsulating the desired inorganic NPs into polymer particles by the use of miniemulsion polymerization, and second, spinning the hybrid polymer particles using polyvinyl alcohol (PVA) as template polymer. It is proved that using green electrospinning, it is not only possible to ensure an excellent distribution and encapsulation of the inorganic NPs along the NFs, but also allows to control and change the concentration, size, and type of the inorganic NPs without altering the NFs size, a fact that is not possible by conventional solution electrospinning. As proof of concept, NFs with up to three different types of inorganic NPs have been created in a single electrospinning step, but this technology allows to incorporate as much inorganic NPs as desired without altering the NFs morphology and ensuring a good distribution and encapsulation of the NPs. This paper demonstrates that green electrospinning is a powerful and attractive technology to create multifunctional NFs that are promising materials for sensing and biomedical applications.     

具有硬核—软壳结构的丙烯酸聚合物乳液的研究

利用种子乳液聚合法合成了具有硬核—软壳结构的丙烯酸聚合物微粒子,通过对种子粒子数和最终粒子数的理论计算,并结合最低成膜温度(MFT)的测试结果,描述了聚合物微粒子的聚合过程,同时,还对聚合物乳液的各项性能进行了研究。     

核壳型醋丙乳液胶黏剂的制备及其性能研究

乳胶粒子形态控制是聚合物乳液研究的重要领域,几十年中在聚合物材料、涂料、胶黏剂等诸多领域的成功的应用使得核壳结构聚合物复合粒子备受关注。采用种子乳液聚合法,采用复配乳化剂体系合成了以醋酸乙烯酯为核,醋酸乙烯酯和丙烯酸丁酯为壳的乳液,并重点研究了单体滴加速率、SDS与OP-10质量比、引发剂用量对乳液性能的影响,通过透射电镜和红外光谱仪表征了乳胶粒子核壳结构的存在。     

水性核（PMMA）／壳（PU）聚氨酯丙烯酸酯杂化乳液的合成研究

合成高Tg低成膜温度的水性聚氨酯丙烯酸酯杂化乳液,研究了合成工艺、—N CO和—O H的比例、丙烯酸酯含量等因素对乳液稳定性和其他性能的影响。     

静电纺丝制备复合纳米纤维方法的研究进展

近年来,复合纳米纤维因其具有优异的特性而引起国内外广泛关注.简要阐述了静电纺丝制备纯纳米纤维的方法,重点综述了静电纺丝构建复合纳米纤维方法的研究进展。     

电纺丝技术制备无机/有机复合纳米纤维的研究进展

静电纺丝法是一种利用聚合物溶液或熔体在强电场中进行喷射纺丝的加工技术,是获得纳米尺寸长纤维的有效方法之一。目前电纺丝技术逐渐转移到无机/有机纳米复合纤维的制备方面。回顾了近年来电纺丝技术制备无机/有机复合纳米纤维的研究进展,包括:半导体纳米粒子/聚合物复合纳米纤维的制备,无机氧化物纳米粒子/聚合物复合纳米纤维的制备以及贵金属纳米粒子/聚合物复合纳米纤维的制备。     

Multiwalled Carbon Nanotubes/CsPbX3@Polyacrylonitrile Core/Shell Nanofibers with Ultrahigh Water,Thermal, and Ultraviolet Stability

The application of all-inorganic perovskite nanocrystals (PNCs) is considerably limited by their inherent instability under the ubiquitous environmental conditions with high water content, temperature, and UV intensity. The multiwalled carbon nanotubes (CNTs) are combined with polyacrylonitrile (PAN) for the first time to improve the uniform luminous performance and environmental stability of PNCs, attributing to the dense growth of PNC via lead ions bound with rich carbonylation on CNT surfaces, the excellent characteristics of CNTs (including hydrophobicity, electrical conductivity, specific heat, UV absorption capacity), the weather resistance of PAN polymer, and their synergistic effect. Here, via one-step single-nozzle electrospinning at room temperature, CNTs, PNCs, and PAN are comprised as core–shell nanofibers (i.e., CNTs/PNCs@PAN) with tunable emissions between 472 and 683 nm, covering the visible light range from blue to red. The photoluminescence intensity of CNTs/CsPbBr₃@PAN can be 93%, 91%, and 91% of the initial value, respectively, after being immersed in water for 20 days, heated to 90 °C, and exposed to 365 nm light irradiation for 48 h, which are superior to those of the previously reported PNCs/PAN fibers. The ultrahigh water stability is further proven by CNTs/PNCs@PAN-based sensor for rhodamine 6G solution fluorescence detection.     

核/壳型苯乙烯-丙烯酸酯共聚乳液及其外墙涂料的研究

采用预乳化、半连续种子聚合法工艺,通过St—BA—MMA—AA四元共聚,研制出了具有核壳结构的苯丙乳液,并以此配制成外墙涂料。着重讨论了乳化剂和丙烯酸的用量,以及核中不同单体用量比对涂料性能的影响,同时用MDSC及IR表征了所得聚合物乳液的结构。     

One‐Step Immobilization of Protein‐Encapsulated Core/Shell Particles onto Nanofibers

A novel method is described to functionalize nanofibers to form a nanocomposite with core/shell particles in order to control protein release. The nanocomposite is produced by electrically neutralizing negatively charged poly(lactic acid) nanofibers with positively charged poly[(lactic acid)‐co‐(glycolic acid)] particles via a one‐step electrohydrodynamic jetting process. The protein‐encapsulated core/shell particles exhibited no significant initial burst release or denaturation. The protein release profile was controlled by porosity and protein/polymer interactions. The method may be promising to engineer intelligent scaffolds that can fulfill the needs of biomimetic materials.

     

种子聚合法制备PS/PAA核壳微球的研究

设计制备了以疏水性聚苯乙烯(PS)为核、以亲水性聚丙烯酸(PAA)为壳的PS/PAA核壳结构复合微球。首先利用无皂乳液聚合法制备了亚微米级的PS微球,再以其为种子,利用种子无皂乳液聚合法制备PS/PAA核壳微球。在种子聚合阶段,选用AIBN当引发剂,经过红外光谱(IR)表征,表明当使用油溶性引发剂偶氮二异丁腈(AIBN),使其最终形成PS/PAA核壳结构微球。这种方法解决了亲水性较强的单体在以水为介质时在PS微球溶于少量的苯乙烯(St),并在引发聚合之前经过充分的吸附溶胀,可使亲水性单体AAc在PS种子微球表面聚合生成壳层,解决表面不容易直接聚合生成壳层的问题。     

核/壳苯丙乳液的合成

采用预乳化工艺和种子乳液聚合技术合成了具有核／壳结构的苯丙乳液，研究了引发剂种类、乳化剂用量及两阶段用量等对苯丙核／壳乳液合成的影响。得到了聚合过程稳定、综合性能好的核／壳型乳液。     

静电纺丝制备具有扭曲螺旋结构的微/纳米纤维

天然纤维大多具有一种自扭曲螺旋结构,这种结构使得天然纤维具有较强的柔韧性和很高的孔隙度。主要介绍了两种可以用来制备扭曲螺旋结构微/纳米纤维的静电纺丝装置,并分别阐述了用这两种装置制备具有自扭曲螺旋结构微/纳米纤维的聚合物体系,最后指出了其发展现状和前景。     

具有核/壳结构的改性硅橡胶微粒的研制

研究了在采用种子乳液聚合法合成具有核／壳结构的改性硅橡胶微粒过程中，作为种子的纯硅橡胶微粒的交联度及其乙烯基含量、表面活性剂种类及其使用浓度，作为形成壳层材料的烯类单体的种类及其用量、以及反应时间和反应温度等因素对生成目的产物的影响。实验结果表明，要得到结构稳定、易分散的具有核／壳结构的改性硅橡胶微粒，需要具有一定交联度和一定数量的乙烯基基团的硅橡胶微粒作为种子，并选用由非离子型表面活性剂和阴离子型表面活性剂组成的复合乳化体系，选用其均聚物具有较高玻璃化温度的烯类单体作为形成壳层的材料，其用量与有机硅部分的用量相当；反应温度５０～９５℃，反应时间大于７ｈ。     

Property and Stability of Astaxanthin Emulsion Based on Pickering Emulsion Templating with Zein and Sodium Alginate as Stabilizer

Astaxanthin loaded Pickering emulsion with zein/sodium alginate (SA) as a stabilizer (named as APEs) was developed, and its structure and stability were characterized. The encapsulation efficiency of astaxanthin (Asta) in APEs was up to 86.7 ± 3.8%, with a mean particle size of 4.763 μm. Freeze-dried APEs showed particles stacked together under scanning electronic microscope; whereas dispersed spherical nanoparticles were observed in APEs dilution under transmission electron microscope images. Confocal laser scanning microscope images indicated that zein particles loaded with Asta were aggregated with SA coating. X-ray diffraction patterns and Fourier transform infrared spectra results showed that intermolecular hydrogen bonding, electrostatic attraction and hydrophobic effect were involved in APEs formation. APEs demonstrated non-Newtonian shear-thinning behavior and fit well to the Cross model. Compared to bare Asta extract, APEs maintained high Asta retention and antioxidant activity when heated from 50 to 10 °C. APEs showed different stability at pH (3.0–11.0) and Na⁺, K⁺, Ca²⁺, Cu²⁺ and Fe²⁺ conditions by visual, zeta potential and polydispersity index measurements. Additionally, the first order kinetics fit well to describe APEs degradation at pH 3.0 to 9.0, Na⁺, and K⁺ conditions. Our results suggest the potential application of Asta-loaded Pickering emulsion in food systems as a fortified additive.     

具有核壳结构的聚苯胺/二氧化硅微球的制备与表征

利用原位聚合(In-situ)方法,在二氧化硅微球表面上成功包覆了聚苯胺层.透射电镜(TEM)照片显示,微球呈现良好的核壳结构,大部分粒径在500 nm左右;包覆后,聚苯胺的红外特征吸收峰发生了红移,表明二氧化硅与聚苯胺两相之间不是简单的物理包覆,而是存在类似于共价键的缔合作用.热重(TG-DTG)曲线显示聚苯胺/二氧化硅微球具有3个明显的失重阶段,并且无机二氧化硅提高了聚苯胺的氧化分解温度.