双亲性无规共聚物P（VM-co-AMPS）的自组装及其性能

以2-丙烯酰胺基-2-甲基丙磺酸（AMPS）和苯乙烯类光敏单体7-（4-乙烯基苄氧基）-4-甲基香豆素（VM）为共聚单体,采用自由基聚合法制备了光敏性双亲共聚物P（VM-co-AMPS）。P（VM-co-AMPS）在溶剂水中自组装胶束化,用原子力显微镜（AFM）表征了自组装胶体粒子的形态、粒径及其分布。紫外光照使胶体粒子中香豆素基元发生光二聚反应,用紫外-可见光分光光度计（UV-Vis）跟踪其光二聚交联过程,用光学显微镜考察了胶体粒子的乳化性能。结果表明：胶体粒子具有较好的紫外吸收性能和较好的乳化性能。该胶束制备工艺简单,条件温和,避免了溶剂的使用。     

光敏性无规共聚物P(FA_2C-co-AA)的自组装及乳化性能

光敏性单体ε-己内酯改性丙烯酸酯肉桂酸酯(FA2C)与丙烯酸(AA)在偶氮二异丁腈(AIBN)的引发作用下,于N,N-二甲基甲酰胺(DMF)中发生自由基共聚反应,制备了具有光敏性的双亲无规共聚物P(FA2C-co-AA)。以红外光谱、凝胶渗透色谱、差示扫描量热和紫外光谱等分析测试手段对共聚产物进行了表征。P(FA2C-co-AA)在选择性溶剂DMF水溶液中自组装得到纳米粒径的胶体粒子。用紫外光引发胶体粒子内双键发生光交联反应,得到稳定的胶体粒子,并用动态激光光散射(DLS)表征了胶体粒子交联前后的粒径变化。结果表明:该胶体粒子具有良好的乳化性能。     

探索光敏性共聚物P(St/CS-alt-MA)的自组装及其乳化行为

以苯乙烯(St)、马来酸酐(MA)、香豆素苯乙烯醚化物(CS)为单体, 通过自由基溶液聚合合成了双亲性交替共聚物P(St/CS-alt-MA), 用凝胶渗透色谱、核磁共振等对聚合物结构进行表征, 并对其溶液自组装及组装体的乳化性进行了研究. 结果表明双亲性P(St/CS-alt-MA)可以在选择性溶剂中进行自组装形成马来酸酐单元为亲水微区、CS与苯乙烯单元为疏水微区的胶体粒子, 用紫外分光光度计, XPS, TEM研究了聚合物胶体粒子性质, 结果显示, P(St/CS-alt-MA)在水溶液中可以形成两亲性聚合物胶体粒子, 亲水单元在胶粒表面富集, 该两亲性聚合物胶体粒子具有良好的乳化性能.     

光敏感三元共聚物的合成及溶液自组装

以一端为肉桂酸酯光交联基元、中间为聚己内酯长柔性链的甲基丙烯酸酯类大单体FM5C为第三单体,与马来酸酐(MAH)及苯乙烯(St)单体以AIBN引发共聚合,制备了光敏感三元共聚物P(FM5C-co-MAH-co-St).该三元共聚物可在选择性溶剂中形成纳米胶体粒子,并可先利用肉桂酸酯基元的光照交联作用使胶体粒子内聚合物交联,进而利用羧酸酐基元与2-氨基吡啶的室温氨解反应改变胶体粒子形态.用FTIR、GPC、1H-NMR等对该聚合物及其氨解产物进行了结构表征.用动态激光光散射(DLS)、透射电镜(TEM)、芘探针等技术研究了该聚合物胶体粒子微观形态、粒径与微环境在光照交联后及氨解后的变化.实验结果表明,P(FM5C-co-MAH-co-St)在选择性溶剂中可自组装成球形胶体粒子,肉桂酸酯光照交联作用使胶体粒子中的聚合物团聚得更加紧密,从而使其粒径更小、疏水区域更加集中;而进一步的室温氨解反应则使聚合物胶体粒子更松散、粒径变大.     

光敏感双亲性梳状SMA聚合物的合成及其胶束化

以含香豆素型苯乙烯类光敏单体(coumarin-containing styrene monomer, CS)与苯乙烯(St)、马来酸酐(MA)为反应单体, 以偶氮二异丁腈(AIBN)为引发剂制备了光敏感三元苯乙烯-马来酸酐共聚物(SMA)双亲交替聚合物P(St/CS-alt-MA), 再利用羧酸酐基元与正辛胺的室温胺解反应获得光敏感双亲性梳状聚合物P(St/CS-alt-MAA8). 用傅立叶变换红外光谱(FTIR)、凝胶渗透色谱(GPC)、1H核磁共振(1H-NMR)等对该双亲梳状聚合物进行结构表征. 通过香豆素基元的光二聚作用, 使梳状聚合物溶解在DMSO中进行光照预交联; 非交联与预交联聚合物分别在选择性溶剂中自组装形成胶束; 利用羧酸基元与NaOH的离子化作用改变聚合物胶束的亲疏水性质. 动态激光光散射(DLS)与芘荧光探针实验表明预交联聚合物胶束较非交联胶束粒径大, 负载芘的能力强; 离子化作用使聚合物胶束解离重组成粒径更小的胶束, 但预交联胶束较非交联胶束小, 离子化后胶束疏水微区更加紧密, 负载芘的能力也增大.     

HA/PDM自组装复合胶体粒子及其乳化性能

以阴离子天然大分子透明质酸(HA)和阳离子单体甲基丙烯酸二甲氨基乙酯(DM)组成带相反电荷的聚合物/单体复合体系, DM通过水相原位聚合可制备荷正电的聚甲基丙烯酸二甲氨基乙酯(PDM), PDM与HA间的静电作用可诱导两者在水溶液中进行自组装, 得到HA/PDM复合胶体粒子. 用傅里叶变换红外(FTIR)光谱仪对HA/PDM复合物结构进行了表征. 用动态激光光散射(DLS)研究了HA与PDM复合体系在水溶液中的自组装行为, 并表征了反应时间对HA/PDM复合胶体粒子粒径的影响. 利用透射电镜(TEM)表征了胶体粒子的形貌. 考察了溶液pH 对胶体粒子粒径及zeta 电位的影响, 并对胶体粒子的乳化性能进行初步探索. 结果表明:DM单体聚合前, 无HA/DM复合物聚集体形成; 而随着DM的逐步聚合, HA与PDM可通过静电作用逐渐组装形成球状HA/PDM复合胶体粒子, 其粒径随反应时间延长逐渐减小并趋于稳定. 同时, 该复合胶体粒子具有pH敏感性和乳化性, 乳化性能较纯HA和PDM有较大提高.     

光交联Pickering乳液中的粒子稳定剂制备胶体体微胶囊

研究了光敏性聚合物刷修饰二氧化硅纳米粒子的制备及其乳化行为, 提供了一种制备新颖“胶体体”微胶囊的方法. 首先, 在二氧化硅纳米粒子表面引入原子转移自由基聚合(ATRP)引发剂分子, 通过表面引发ATRP得到含有香豆素侧基聚合物刷光敏性的纳米二氧化硅粒子(SiO₂-PMMA-PCMA); 然后, 以该粒子为乳化剂制备油包水型的皮克林乳液; 最后, 在紫外光的照射下引发香豆素侧基的交联反应从而得到“胶体体”微胶囊. 结果表明, 香豆素单体7-(2-甲基丙烯酰乙氧基)-4-甲基香豆素(CMA)和SiO₂-PMMA-PCMA在紫外光作用下都可以发生交联反应, 以SiO₂-PMMA- PCMA纳米粒子作乳化剂可以制备稳定的皮克林乳液, 光交联后得到的“胶体体”微胶囊的平均粒径约为170 μm.     

香豆素改性透明质酸颗粒乳化剂的制备及应用

利用7-(2-羟基乙氧基)-4-甲基香豆素(HEMC)疏水改性透明质酸(HA)制得光敏双亲大分子(HA-HEMC),并通过自组装形成了HA-HEMC胶体粒子。通过核磁共振氢谱和紫外分光光度计确定了HA-HEMC的结构及取代度;采用动态激光光散射、纳米粒度仪和透射电镜等手段对胶体粒子的性质及形貌进行了表征。进一步以HA-HEMC胶体粒子作为颗粒乳化剂稳定油水界面,研究了胶体粒子质量浓度、油相类型、水相pH和盐浓度对胶体粒子乳化性能的影响。结果表明:HA-HEMC可以在选择性溶剂中自组装形成粒径约为236nm的球形胶体粒子;该胶体粒子能够在较宽的pH范围内(3~11)稳定水包油型乳液且所得乳液有良好的耐盐性;此外,HAHEMC胶体粒子还能稳定多种油-水体系。     

双亲性共聚物P(St/VBT-co-MA)自组装胶束的制备及其乳化性能

以1-(4-乙烯基苄基)胸腺嘧啶(VBT)、苯乙烯(St)、马来酸酐(MA)为共聚单体,采用自由基聚合法制备了双亲性共聚物P(St/VBT-co-MA)(PSVM)。PSVM在选择性溶剂N,N-二甲基甲酰胺(DMF)的水溶液中进行自组装可形成胶束。利用透射电镜(TEM)和动态激光光散射(DLS)表征了自组装胶束的形态和粒径分布。以该胶束作为颗粒乳化剂稳定白油-水体系形成乳液,研究了PSVM胶束浓度、pH、盐浓度等对其乳化性能的影响,并用光学显微镜(OM)表征了其乳液形态。结果表明:通过自由基聚合的方法成功合成了双亲共聚物PSVM,其自组装形成粒径分布均匀的球形胶束;该胶束具有优异的乳化效率,其乳液长期稳定且具有pH响应性及强耐盐性,静置四个月后,乳液仍具有良好的乳化效果且乳液层高度基本不变。     

共溶剂性质对双亲性无规共聚物P(St-co-DM)胶束化行为及其性能的影响

以苯乙烯(St)和甲基丙烯酸二甲氨乙酯(DMAEMA)为共聚单体, 通过普通自由基溶液聚合合成了双亲性无规共聚物P(St-co-DM). 用傅里叶变换红外(FTIR)光谱、核磁共振氢谱(¹H NMR)、凝胶渗透色谱(GPC)和差示扫描量热(DSC)仪对聚合物结构进行表征. 研究了共溶剂的性质对P(St-co-DM)自组装胶束结构及其乳化性能的影响. 用透射电镜(TEM)和动态激光光散射(DLS)表征了自组装胶体粒子的形态、粒径大小及其分布. 通过测量胶束在甲苯/水界面的接触角表征胶束表面性能. 结果表明: P(St-co-DM)以四氢呋喃(THF)为共溶剂自组装时, 胶束的临界聚集水含量较大, 胶束表面亲水性较强, 流体力学半径较大; 用二氧六环或THF为共溶剂, 水为选择性溶剂, P(St-co-DM)自组装可以得到外层松散、内层比较密实的球状胶束, 用N,N-二甲基甲酰胺(DMF)为共溶剂时, 胶束整体呈现比较密实的球状胶束; 分别用DMF、二氧六环和THF为共溶剂制备的胶束, 其接触角均值都小于90°, 可形成O/W型(水包油型)乳液. 乳化实验结果表明, 以二氧六环和THF为共溶剂制备的胶束作为颗粒乳化剂制备的乳液性能较好.     

Polar Gradient Latex Particles with Hydrophilic Core and Hydrophobic Shell Prepared via Multistep Emulsion Polymerization

Monodisperse polar gradient particles were synthesized via a three‐step emulsion polymerization using poly(butyl acrylate‐methyl methacrylate‐methacrylic acid‐ethylene glycol dimethacrylate) (P(BA‐MMA‐MAA‐EGDMA)) as core, poly(methyl methacrylate‐methacrylic acid‐styrene) (P(St‐MMA‐MAA)) as interlayer and polystyrene (PSt) as shell. The particle growth and encapsulation in each emulsion polymerization step were followed by transmission electron microscopy (TEM), dynamic light scattering (DLS) and conductometric titration. Results indicated that the feeding mode and the interlayer were essential to prepare the polar gradient latex particles with hydrophilic core and hydrophobic shell. The morphologies of the two‐layer core/interlayer and three‐layer core/interlayer/shell particles were observed in TEM micrographs, and the sequential encapsulations of the carboxyl‐containing core and the core/interlayer particles were confirmed by an increase in the particle size as well as an increase in the buried carboxyl percentage.     

The Preparation and Properties of Polyurethane/Nano-CeO<Subscript>2</Subscript> Hybrid Aqueous Coating

To improve the ultraviolet resistance and thermal stability of waterborne polyurethane, stable waterborne polyurethane/nano-cerium oxide hybrid dispersions were obtained by adding nano-cerium colloids to previously synthesized waterborne polyurethane dispersions. The dried ceria colloid was characterized by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). The XRD results indicated the prepared CeO₂ was a face-centered cubic structure. The prepared polyurethane/CeO₂ dispersions were studied by dynamic light scattering (DLS), transmission electron microscopy (TEM), UV–Vis spectroscopy and accelerated weathering test. The dried polyurethane/CeO₂ films were characterized using thermogravimetric analysis (TGA). The DLS analysis indicated the particles average diameter of hybrids emulsion was bigger than that of the pure waterborne polyurethane dispersion. TG analysis and accelerated weathering test suggested the hybrid latex films had better thermal stability and mechanical properties than those of the pure waterborne polyurethane. The UV–Vis absorption capacity of the dispersions prepared was increasing with the amount of CeO₂ colloid increased.     

交替共聚物P(St-alt-Ma-Dopa)的自组装及乳化性能

以二甲亚砜(DMSO)为溶剂, 用多巴胺(Dopamine)胺解聚(苯乙烯-alt-马来酸酐)(P(St-alt-Man))制备双亲交替共聚物P(St-alt-Ma-Dopa). 在选择性溶剂(N,N-二甲基甲酰胺(DMF)/水)中对P(St-alt-Ma-Dopa)进行溶液自组装, 用紫外分光光度计(UV)、透射电镜(TEM)、荧光探针技术、zeta电位仪等技术研究了添加剂(HCl, NaOH或NaCl)对P(St-alt-Ma-Dopa)自组装行为的影响及其胶体粒子的乳化性能. 结果表明, P(St-alt-Ma-Dopa)链在选择性溶剂(DMF/水)中可自组装形成球状胶体颗粒, 其临界聚集水含量(CWC)明显大于P(St-alt-Man). 体系的pH值、盐浓度等对P(St-alt-Ma-Dopa)胶体粒子的性质(粒子大小、zeta电位、亲疏水性等)有较大的影响, 引入多巴胺结构使交替共聚物胶体粒子的乳化性能有所提高.     

Facile synthesis of hollow polymer microspheres with movable cores with the aid of hydrogen-bonding interaction

Poly(divinylbenzene-co-acrylic acid) (poly(DVB-co-AA)) hollow microspheres with movable poly(DVB-co-AA) cores were prepared by a facile route. In this approach, poly(DVB-co-AA) microspheres were first used as templates to synthesize poly(DVB-co-AA)@PAA core-shell particles with a non-crosslinked PAA shell by distillation precipitation polymerization in acetonitrile. In situ polymerization to prepare poly(DVB-co-AA)@PAA@poly(DVB-co-AA) trilayer microspheres was then developed, in which the hydrogen-bonding interaction between the carboxylic acid groups played a key role as the driving force for the formation of monodisperse trilayer structure polymer microspheres. After removal of the non-crosslinked poly(acrylic acid) (PAA) midlayer of the poly(DVB-co-AA)@PAA@poly(DVB-co-AA) microspheres in ethanol under basic conditions, poly(DVB-co-AA) hollow microspheres with movable poly(DVB-co-AA) cores were obtained. Functional poly(DVB-co-AA) cores could be released successfully when the hollow structure was destroyed. The resultant core-shell, trilayer polymer microspheres and hollow polymer microspheres with movable cores were characterized by transmission electron microscopy (TEM), dynamic laser scattering (DLS), and Fourier transform infrared (FT-IR) spectra.     

Luminescent amphiphilic nanogels by terpyridine-Zn(II) complexation of polymeric micelles

In this work, we investigated terpyridine (tpy)/Zn(II) complexation for the crosslinking of polymeric micelles of the branched poly(ethylene oxide)–poly(propylene oxide) block copolymer Tetronic® 1107 (T1107) in water and produce physically stable amphiphilic luminescent nanogels. Nanoparticles displayed a size of 235 ± 25 and 318 ± 57 nm before and after Zn(II) crosslinking, respectively, as measured by dynamic light scattering. High-resolution scanning electron microscopy analysis revealed the multimicellar nature of the crosslinked nanoparticles. In addition, Zn(II) complexation prevented nanoparticle disassembly after extreme dilution below the critical micellar concentration and reduced the minimum concentration required for the reverse thermal gelation of concentrated aqueous T1107 systems. The cell compatibility and uptake were initially assessed in the murine macrophage cell line RAW 264.7. Results showed that complexation increases the cell compatibility of the nanoparticles with respect to the non-complexed counterparts. In addition, non-crosslinked nanoparticles accumulated in the cell membrane, while the complexed ones were internalized, as observed by confocal laser scanning fluorescence microscopy. Then, the antiproliferative activity of the crosslinked nanoparticles was confirmed in the rhabdomyosarcoma cell line Rh30; their inhibitory concentration 50 (IC₅₀) being 101 μg/mL (6.7 μM). Finally, the encapsulation and release of the hydrophobic antiretroviral efavirenz was characterized in vitro. Complexation slightly reduced the release kinetics with respect to the pristine nanoparticles. Overall results demonstrate the promise of this simple modification strategy to produce amphiphilic nanogels with a set of advantageous physicochemical, optical, and biological properties.     

无皂乳液聚合制备光敏聚合物微球及其光响应性

利用红外光谱(IR)和核磁共振(1H NMR)对所制备的光敏可聚合单体重氮萘醌苯磺酸甲基丙烯酸羟乙酯(DNQMA)进行了表征. 采用无皂乳液聚合方法制备DNQMA与甲基丙烯酸叔丁酯(t-BMA)的共聚合光敏微球. 利用紫外光谱(UV/Vis)、动态光散射(DLS)、扫描电镜(SEM)对光敏微球在光照前后形态的变化进行了表征. DLS的研究结果表明在水分散液中, 光敏微球的尺寸随光照时间的增加, 先增大, 然后达到平衡. 这与紫外光谱中DNQMA特征吸收达到饱和的时间相一致. SEM研究结果表明光敏微球的形态在光照后破坏很严重, 并基本解体.     

Fluorescent Vesicular Particles Assembled by Inclusion Complexes Between Cyclodextrins and BPB

Vesicular particles based on inclusion complexes between BPB and γ-HB-β-CDs were prepared and characterized for the first time. The morphologies and sizes were confirmed by transmission electron microscopy (TEM), scanning electron microscope (SEM), and dynamic light scattering (DLS). Particularly, these vesicular particles exhibiting clearly fluorescent dots observed by laser confocal scanning microscopy (LCSM) could be alternative candidates as fluorescent probes and labels being applied to cellular staining, labeling, bio-mimicking and drug delivery. The ultraviolet, fluorescence, and nuclear magnetic resonance (NMR) measurements confirmed the existence of stable 1:1 BPB-γ-HB-β-CD complexes in the system. The vesicular particles were assumed to be constructed by orderly self-aggregates of these inclusion complexes.