微晶纤维素丙烯酸酯复合磁性微球的制备

采用反相悬浮聚合法合成一种微晶纤维素丙烯酸酯复合磁性微球,并对磁性微球的内部结构和性能进行了分析,结果表明微晶纤维素被包埋在聚丙烯酸酯内部而Fe₃O₄被包裹在微球内部孔洞中,通过磁性分析,此微晶纤维素丙烯酸酯复合磁性微球为具有半硬磁性的微球材料。     

锰锌铁磁性复合微球的制备及对头孢噻肟钠的吸附性研究

采用反向悬浮聚合法,以自制的锰锌铁氧体和四氧化三锰磁性颗粒为核,以淀粉为壳,制备磁性复合微球。利用磁天平(CTP)、扫描电镜(SEM)、红外光谱(IR)及紫外分光光度计(UV-Visible)对微球进行表征。以头孢噻肟钠(CTX)针剂为吸附对象考察微球对药物的吸附量。结果表明,磁性复合微球球形规整,分散性好,四氧化三锰磁性淀粉微球的交联度和磁含量均较锰锌铁(Mn-Zn ferrite)氧体磁性淀粉微球的高,对头孢噻肟钠的饱和吸附量为9.8 mg/g。     

BaFe12O19/聚氨酯磁性复合微球的制备和表征

通过BaFe12O19硅烷偶联剂改性,聚乙二醇1000、甲苯二异氰酸酯在二甲苯溶液中预聚合,预聚物溶液在分散剂聚乙烯吡咯烷酮K30的水溶液中悬浮聚合,三步合成了BaFe12O19/聚氨酯复合微球.用扫描电镜、红外光谱仪、热重-差示扫描同步热分析仪和振动样品磁强计对微球的形貌、结构、玻璃化温度(Tg)和磁性能进行了表征.结果表明:合成的微球以BaFe12O19颗粒为核聚氨酯为壳.表面分布有微孔,微球粒径在400μm左右,粒径大小可通过控制反应条件调节.微球中磁性物质BaFe12O19的含量为11.11%(质量分数),Tg在290 ℃左右,耐热性能好,微球的饱和磁化强度为3.36×103 A/m,矫顽力为3.06×104 A/m.该复合微球是一种有潜在应用价值的新型血管内栓塞材料.     

新型悬浮聚合法制备多孔磁性高分子微球的研究

采用新型悬浮聚合法制备了平均粒径为4.06 μm的多孔磁性高分子微球.以硅烷偶联剂KH-570对羰基铁粉颗粒进行表面修饰,并经一步聚合得到多孔磁性高分子微球.SEM结果表明该微球表面由纳米级聚合物粒子层层粘合而成,粒子间孔径在几十到几百纳米之间不等.采用红外光谱及X射线衍射表征了多孔磁性高分子微球的化学成分和晶体结构.用热失重方法测得多孔磁性高分子微球中磁性物质的含量可达26.7%.     

石蜡聚苯乙烯微球的制备Ⅱ.分散剂及复合介质的影响

通过悬浮聚合法合成了石蜡聚苯乙烯微球,研究了合成过程中复合介质的配比和用量以及分散剂种类和用量对微球粒径及其分布的影响。结果表明:采用聚乙烯醇作分散剂,更有利于合成小粒径高产率的石蜡聚苯乙烯微球,悬浮聚合体系中水-乙醇复合介质的最佳体积配比和用量分别为1:2.5和150mL。     

分散剂及复合介质对石蜡-聚苯乙烯微球合成的影响

通过悬浮聚合法合成石蜡-聚苯乙烯微球,研究了合成过程中复合介质的配比和用量以及分散剂种类和用量对微球粒径及其分布的影响。实验结果表明:采用聚乙烯醇作分散剂,更有利于合成小粒径、高产率的石蜡-聚苯乙烯微球,悬浮聚合体系中水-乙醇复合介质的最佳体积配比和用量分别为1:2.5和150mL。     

羟基磁性微球的制备及表征

本研究以共沉淀法制备的Fe3O4为核,采用溶胶-凝胶法,使用正硅酸乙酯(TEOS),在Fe3O4表面包覆一层Si O2,进而用硅烷偶联剂3-(异丁烯酰氧)丙基三甲氧基硅烷对Fe3O4@Si O2复合微球进行表面改性,制得表面含有双键核壳结构的Fe3O4@Si O2复合磁性微球。采用乳液聚合法,将复合磁性微球与功能单体甲基丙烯酸羟乙酯(HEMA)共聚,得到表面带有羟基的高分子磁性微球。对所制备的复合磁性微球用傅里叶红外光谱(FT-IR)、扫描电镜(SEM)以及X射线衍射(XRD)进行表征,结果表明,成功制备出了单分散性良好的功能性高分子羟基磁性微球。     

磁性两性淀粉复合微球的制备及吸附性能研究

以玉米淀粉和环氧丙烷为原料,制备了交联淀粉,接着采用半干法合成了高取代度的磁性两性淀粉。然后以两性淀粉、FeCl_2和FeCl_3为原料,采用混合共沉淀法制备了磁性两性淀粉复合微球。对复合微球进行了IR、SEM、VSM表征,结果表明:复合微球呈不规则球形、表面粗糙、平均粒径为20nm,同时具有超顺磁性,易于实现磁分离。以甲基橙和次甲基蓝为客体分子,测定了磁性两性淀粉复合微球的吸附性能并优化了合成条件。由甲基橙的吸附效果得出制备阳离子淀粉的最佳条件为:淀粉5g,NaOH 0.98g,醚化剂2.85g,水占体系25%,80℃下反应2.5h。由次甲基蓝的吸附效果得出制备阴离子淀粉的最佳条件为:阳离子淀粉5g,碱0.36g,氯乙酸钠0.87g,60℃下反应2h。当淀粉与氧铁比例不超过1∶1时,磁性两性淀粉复合微球对甲基橙及次甲基蓝的吸附率都接近100%。当超过这一比例时,吸附率有所下降。     

磁性高分子微球的制备

磁性微球是一种新型功能材料,具有磁效应和小尺寸效应,在众多领域展现出巨大的应用潜力。本文综述了磁性微球的制备方法,磁性高分子微球目前有三种主要的的制备方法:包埋法、原位沉积法、单体聚合法。单体聚合法又以悬浮聚合法、乳液聚合法、分散聚合法为主。     

羧基磁性高分子微球的制备和表征

用改进的悬浮聚合法制备了表面含有羧基功能团的聚苯乙烯磁性微球。考察了磁微球的形态与结构 ,测定了磁微球的粒径与磁响应性 ,主要研究了单体 /水、丙烯酸 /单体、反应温度和反应时间对磁性微球形成的影响 ,并对磁性微球的生物吸附活性进行了表征。优化得到了制备具有良好生物吸附活性的羧基磁性微球的最佳实验条件     

化学沉积法制备高分子复合导电微球

研究了聚苯乙烯微球表面化学沉积铜的速度及其影响因素，确定了最佳工艺参数。ＳＥＭ分析表明，本工艺制得的微球表面铜沉层厚度均匀，与基体间结合牢固，微球本身具有很好的导电性。     

无皂乳液聚合制备阳离子功能性微球研究

苯乙烯 (St) /丙烯酸丁酯 (BA)体系在无乳化剂的条件下分别与少量的自制的 N,N-二甲基 ,N-丁基 ,N-甲基丙烯酰氧乙基溴化铵 (DBMEA)、N,N-二甲基 ,N-丁基 ,N-(3-甲基丙烯酰胺基 )丙基溴化铵 (DBMPA)进行共聚 ,通过离子交换—电导滴定确定了两体系微球表面基团及粒子表面电荷密度 ,认为微球大小及表面电荷密度主要由引发剂浓度、共聚单体浓度、离子强度、St/BA主单体比及单体加料方式决定。粒子的形态规则 ,大小均一、表面干净。     

药物偶联亲和高分子微球对牛血蛋白吸附性能研究

在制备亲和高分子乳液微球基础上,对其进行空间臂改性和药物分子偶联制得PSGN-MTA亲和高分子微球药物。为研究亲和高分子微球生物相容性,考察了高分子微球药物在缓冲液中药物释放行为及对BSA蛋白吸附能力。结果表明,亲和微球表面化学键合MTA药物浓度较高且分布均匀时,对BSA蛋白的吸附过程较符合一级动力学方程。还考察了pH值对BSA蛋白吸附的影响,中性条件时PSGN-MTA微球对于BSA吸附效果较好。     

Novel poly(3‐hydroxybutyrate) composite films containing bioactive glass nanoparticles for wound healing applications

Bioactive glass is considered an ideal material for haemostasis as it releases Ca²⁺ ions upon hydration, which is required to support thrombosis. In this study the effects of the presence of nanoscaled bioactive glass (n‐BG) in poly(3‐hydroxybutyrate) (P(3HB)) microsphere films on the structural properties, thermal properties and biocompatibility of the films were studied. The n‐BG with a high surface area was also tested for its in vitro haemostatic efficacy and was found to be able to successfully reduce clot detection time. In an effort to study the effect of the roughness induced by the formation of hydroxyapatite on cellular functions such as cell adhesion, cell mobility and cell differentiation, the composite films were immersed in simulated body fluid for periods of 1, 3 and 7 days. From scanning electron microscopy images, the surface of the P(3HB)/n‐BG composite microsphere films appeared fairly uniform and smooth on day 1; however on day 3 and day 7 a rough and uneven surface was observed. The presence of hydroxyapatite on the composite microsphere films on day 3 and day 7 influenced the surface roughness of the films. However, when the P(3HB)/n‐BG composite microsphere films with enhanced surface roughness were tested for biocompatibility, reduced amounts of protein adsorption and cell adhesion were observed. This study thus revealed that there is an optimal surface roughness for the P(3HB) microsphere films for increased cell adhesion, beyond which it could be deleterious for cell adhesion and differentiation. © 2016 Society of Chemical Industry     

TiO2纳米晶/空心玻璃微珠复合填料的制备与研究

采用化学沉积法使TiO2以纳米粒子的形式包覆于空心玻璃微珠表面,成功制备了TiO2纳米晶/空心玻璃微珠复合填料.分别用扫描电镜(SEM)及紫外可见近红外分光光度计对产物进行了晶体形貌观察及光反射性能测试.结果表明:TiO2在空心玻璃微珠表面包覆效果良好,且经过热处理后空心玻璃微珠破损率很低,二氧化钛纳米晶尺寸为5～50 nm,膜层厚度为50～500 nm;光谱分析表明:该复合粉体对可见光和近红外波段的太阳光辐射具有很高的反射率(＞95%).将改性空心微珠、空心玻璃微珠及国外较好的玻璃微珠分别作为填料制备隔热涂料,光谱分析表明:以改性微珠作为填料制备的涂料,漆膜对太阳光主要能最波段(500～1500 nm)的光反射性能得到显著提高,当涂料与改性微珠质量比为100:15时,漆膜的光反射效果最佳,平均光反射率高于85%,该性能指标优于空心玻璃微珠及国外同类产品.     

热固性酚醛树脂基微球的制备方法的研究

球形活性炭由于其特殊的几何结构和多孔性,在许多方面得到了应用研究。实验以热固性酚醛树脂为原料,采用乳化法制备酚醛树脂基微球。研究了表面活性剂的结构、表面活性剂的用量、搅拌速度和分散比对成球的影响。研究结果表明：选择有分支结构的表面活性剂可以得到球形度良好的微球。酚醛树脂基微球的球径随着搅拌速度的增加,先增加后又有所降低;随着分散比的增加,球径减小。Span85的用量为1．5g、搅拌速度在300～400r／min之间,分散比为8：100时可以得到球形度良好的酚醛树脂基微球。     

双分散反相悬浮聚合制备吸水微球方法及装置

针对反相悬浮聚合存在热力学不稳定、分散剂难于清洗及难以实现工业化生产的缺点,基于落球法测黏度原理,建立了先后采用机械搅拌分散和自然沉降分散的反相悬浮聚合制备微球的方法,并设计了制备装置。该方法依靠搅拌速度及水相与油相体积比确定球径,然后在不采用分散剂的条件下,利用自然动力使微球边沉降边反应,有效避免微球粘连结块;制备装置结构简单,可实现连续生产,反应釜体高度需大于2 m以保证足够的反应时间,釜体材质为非极性材料以防止微球吸附釜壁。聚丙烯酰胺微球制备实验表明,制备工艺易于操作,微球不存在粘连,分散介质可重复使用,且无污染,便于工业化生产。     

Immobilization of glucoamylase on polymer surface by radiation-induced polymerization of glass-forming monomers at low temperatures

Glucoamylase was immobilized in hydrophilic porous poly(2-hydroxyethyl methacrylate) (PHEMA) and hydrophobic microsphere poly(diethylene glycol dimethacrylate) (PDGDA) by radiation-induced polymerization at low temperatures, in the presence of acetate buffer solution. The distribution on the matrix of immobilized glucoamylase was investigated using fluoresce in isothiocyanate (FITC)-conjugated glucoamylase and the fluorescence microscope. It was found that in the porous PHEMA system, the FITC-conjugated glucoamylase is present mainly on the interface between polymer membrane and pore structure and partly in the polymer, while in the microsphere PDGDA system the immobilized glucoamylase is present merely on the surface of the polymer microsphere.     

空心微珠化学镀银研究

使用钛酸酯偶联剂对空心微珠表面进行处理后再进行超声波辅助化学镀银,并借助SEM、EDX、XRD和XPS检测技术对镀层结构、表面形貌和成分进行了分析。研究结果表明,不同还原剂化学镀银微珠的导电性有所差异,其中葡萄糖镀银微珠导电性最好。不同还原剂化学镀银微珠表面形貌明显不同,由此引起表面反射光谱的不同。     

Carboxylic acid functionalized MWNT coated poly(methyl methacrylate) microspheres and their electroresponse

The effect of solvent on adsorption of the multi-walled carbon nanotube (MWNT) onto poly(methyl methacrylate) (PMMA) microspheres is examined and then their electrorheological (ER) behavior under an applied electric field when dispersed in a silicone oil is observed, using the MWNT which was initially modified with carboxylic acid functional groups on its outside wall through an oxidation treatment (c-MWNT). The c-MWNT was successfully incorporated onto the PMMA microsphere surface in either Di-water or methanol, while the adsorption state of the c-MWNT is strongly dependent on the solvent used. The dense and well dispersed c-MWNT is found to be more strongly attached onto the surface of PMMA microspheres when prepared in Di-water than in methanol. It is believed that hydrogen bonding component in the Hansen solubility parameter is a principal factor determining dispersion state of the c-MWNT in the solvent, because the nanotubes used have carboxylic acid functional groups on their surface forming hydrogen bonding between c-MWNT and the solvent. Moreover, c-MWNT/PMMA microsphere as an ER material dispersed in a silicone oil is observed to exhibit typical ER characteristics of fibril structure under an applied electric field, and the ER characteristics are found to be influenced by the conductivity of c-MWNT/PMMA microspheres.