超支化聚(胺-酯)接枝改性纳米TiO_2的研究

提出了一种对纳米TiO2表面进行化学改性的新方法,即利用硅烷偶联剂KH550进行表面预处理,得到接枝有KH550的纳米TiO2,在此基础上以改性纳米TiO2为中心核,通过与AB2型单体进行缩聚反应,在纳米TiO2的表面原位接枝超支化聚(胺-酯)(HBP)。红外光谱、热失重和透射电镜的测试结果表明纳米TiO2表面接枝上了超支化聚合物,接枝率约为15%。研究结果表明,纳米TiO2经超支化聚(胺-酯)接枝改性后,在乙醇和氯仿中的分散性和稳定性得到提高。     

超支化聚(胺-酯)接枝改性纳米二氧化硅增韧增强PVC的研究

用偶联削KH-550和超支化聚（胺-酯）对纳米SiO2进行改性,并通过熔融共混法制得了PVC／SiO2复合材料。利用透射电镜、扫描电镜、力学性能测试等方法研究了复合材料的结构和性能。结果表明,通过超支化聚（胺-酯）的接枝改性可以明显提高纳米SiO2在PVC基体中的分散均匀性;超支化聚（胺-酯）接枝改性纳米SiO2的加入可有效提高PVC的力学性能,且添加量为1％时,效果最好,同时PVC的加工性能也有所改善。     

纳米二氧化硅表面改性研究

采用甲苯二异氰酸酯(TDI)接枝聚乙二醇(PEG)对纳米SiO2进行表面改性,并利用红外光谱(FTIR)和热重(TG)、扫描电镜(SEM)、粒径分析、重力沉降法等方法对改性前后的纳米SiO2的表面形貌和在介质中的分散稳定性进行了表征和分析.结果表明,改性后的纳米SiO2表面接枝上了TDI、PEG的有机官能团,降低了颗粒...     

MASC-SiO_2杂化颗粒的制备、表征与分散性能

合成马来酸酐-十二烯-苯乙烯梳形共聚物(MASC),利用球磨工艺将MASC接枝到SiO2颗粒表面,对聚合物进行核磁共振氢谱和红外光谱分析,对杂化颗粒进行红外光谱分析、热重、接触角、透射电镜和透光度测试。结果表明,颗粒表面的最大接枝率为21.05%;当聚合物与纳米SiO2质量比为1∶1时,接触角为140°;调整共聚物与颗粒的质量比可使改性后的颗粒在不同极性的有机溶剂中有良好的分散性。     

聚苯乙烯/纳米SiO2复合颗粒制备与表征

为改善二氧化硅(SiO2)纳米粒子与聚合物基体间的亲和性,使SiO2表面功能化,将硅烷偶联剂KH-570引入C=C基团,采用乳液聚合方法在纳米SiO2粒子表面接枝苯乙烯(St)单体,实现了纳米二氧化硅表面的聚苯乙烯(PS)高分子包覆改性,制备了具有核/壳结构的SiO2-PS复合纳米粒子,产物的单体转化率和接枝效率在80%以上.研究了二氧化硅含量和偶联剂用量对聚合反应的单体转化率和接枝效率的影响,探讨了偶联剂的作用机理,利用FT-IR、TEM、TG对SiO2-PS复合粒子的表面结构进行了表征.结果表明,复合粒子具有明显的核壳结构,壳层厚度在20nm左右,乳液聚合过程可有效使二氧化硅的团聚体剥离呈纳米级颗粒.     

甲基丙烯酸甲酯对纳米SiO2的表面接枝聚合改性研究

将经过硅烷化处理的偶联剂γ-MPS接枝到纳米SiO2表面,然后在引发剂AIBN的作用下引发单体MMA发生自由基聚合包覆.利用FTIR、TG、CA(接触角)以及TEM等手段分别表征了改性工艺条件对粒子改性前后化学组成结构、接枝率、表面亲水性以及形貌等的影响.系统研究了单体用量、引发剂用量以及反应时间对SiO2/γ-MPS/PM-MA纳米复合粒子接枝改性效果的影响.结果表明,经过PMMA接枝包覆制得了高接枝率的复合粒子,并大大改善了纳米粒子的分散性.     

二氧化硅/聚合物纳米复合材料的研究进展

目的总结二氧化硅(SiO2)/聚合物纳米复合材料的制备方法以及应用等最新研究进展。方法分别从物理法、化学法两大类对国内外SiO2/聚合物纳米复合材料的制备方法优缺点进行阐述总结,并结合SiO2的特点对其应用现状进行详细描述。结果两大方法中,化学法所制备的SiO2/聚合物纳米复合材料分散性好、功能多样、性能高,是目前制备SiO2/聚合物纳米复合材料的最常用方法。SiO2/聚合物纳米复合材料在多功能涂料涂层以及生物医学和环境等领域具有重要应用。结论SiO2/聚合物纳米复合材料的制备方法日趋完善,但在其制备过程中依然存在部分问题尚未解决;对SiO2颗粒进行化学接枝和表面改性,改善其在聚合物材料中的分散,可以进一步改善和拓宽SiO2/聚合物纳米复合材料的应用范围,这也是未来SiO2研究的重要发展方向之一。     

介孔SiO_2接枝改性及应用研究进展

介孔SiO2(MSN)在药物输送、酶固定和催化等领域有广泛的应用。由于MSN极易团聚,使其应用受到限制。接枝改性能有效地改善这一缺点,接枝改性包括小分子改性和聚合物改性。主要介绍了原子转移自由基聚合方法(ATRP)对MSN的接枝改性,ATRP方法可以控制聚合物链的长度。详细介绍了接枝改性后的MSN在作为催化剂载体、作模板制备纳米粒子、药物控释和废水处理等方面应用的现状。     

纳米SiO2表面改性及其应用在复合材料中的研究进展

简单介绍了纳米SiO2改性目的及改性机理,对近年来国内外纳米SiO2表面改性方法及聚合物/纳米SiO2复合材料（PSN）的应用进行了阐述,并对未来的研究内容和方向提出了展望。     

改性聚硅氧烷/纳米SiO2杂化膜的制备与疏水性

先以甲基丙烯酸十八醇酯(SMA)、烯丙基缩水甘油醚(AGE)和含氢硅油(PHMS)的硅氢加成反应制得一种梳状结构的十八酯基/环氧基改性聚硅氧烷(PSAMS),再通过其与氨基功能改性纳米SiO2间的接枝共聚反应制备了一种改性聚硅氧烷/纳米SiO2杂化材料(PSAMS-SiO2).采用一次浸渍法,简便地在天然棉纤维表面制得...     

超支化聚合物在炭黑表面接枝改性的研究

以羟甲基化炭黑为中心核,利用其活性羟基与AB3型单体进行缩聚反应,在炭黑的表面原位接枝超支化聚合物。实验表明,炭黑表面接枝超支化聚合物后,粒子间聚集作用减弱,在乙醇中的分散性和稳定性提高,且对PVC有很好的增强、增韧作用。     

Grafted glycopolymer-based receptor mimics on polymer support for selective adhesion of bacteria

A sugar-containing monomer (2-lactobionamidoethyl methacrylate, LAMA) was grafted on a polypropylene (PP) microfiltration membrane surface by UV-induced graft copolymerization. The degree of grafting can be controlled by variation of monomer concentration, UV irradiation time, and photoinitiator concentration. Fourier transform infrared spectroscopy and scanning electron microscopy were employed to confirm the surface modification on the membranes. The water contact angle was used to evaluate the hydrophilicity change of the membrane surface before and after modification. Bacteria capture experiments showed that the membrane could selectively bind E. faecalis while adhesion of S. maltophilia was not influenced by the functionalization of PP with grafted poly(LAMA). The adhesion of E. faecalis onto poly(LAMA) grafted membrane could be inhibited by 200 mM galactose solution; however, glucose solution showed no inhibition effect. Moreover, occupying sugar residues on the membrane surface primarily by a galactose targeting lectin, peanut agglutinin, could significantly suppress the following adhesion of E. faecalis. All these results clearly demonstrate that this poly(LAMA) grafted PP membrane can selectively capture E. faecalis and that this selection is based on the interaction between galactose side groups on grafted flexible functional polymer chains on the membrane surface and galactose binding protein on the E. faecalis cell membrane.     

新型超支化聚羟甲基醚液晶的合成

合成了联苯氰类介晶基元。改变软段的长度对超支化聚羟甲基醚进行改性。POM，DSC的研究表明。当n=1时，改性超支化聚羟甲基醚不表现出液晶性；n=5,10时，改性超支化聚羟甲基醚表现出液晶性，且为向列型液晶。     

Modification of polypropylene fibers by plasma and preparation of hybrid luminescent and rodlike CdS nanocrystals/polypropylene fibers

A simple method for the preparation of hybrid luminescence and rodlike CdS nanoclusters/poly (propylene-grafted-(2-methylacrylic acid 3-(bis-carboxymethyl amino-2-hydroxy-propyl ester) (GMA-IDA fibers, by plasma induced method following chemical deposition method, is presented in this study. GMA-IDA chelating groups which are grafted onto the poly(propylene) fibers are the coordination sites for chelating Cd+2, on which nano-sized CdS nanocrystals grew. TEM observations demonstrate that the mean diameter of CdS nanocrystals inside the poly(PP-graft-GMA-IDA) fibers alters from 2 nm to 8 nm at various concentrations of S2- solution. Additionally, SEM presents that the CdS nanocrystals on the surface have rod-like structure. The UV-vis absorption spectra provide the information of the absorption edges, band-gaps, and average diameter of CdS nanocrystals, the results of which are coincidence with the TEM observations. Furthermore, the photoluminescence (PL) shows the maximum peaks are 495 nm, 571 nm, 657 nm, and 675 nm corresponding to the mean particle sizes 2.6 nm, 3.5 nm, 4.8 nm, and 7.7 nm, respectively, at an excitation wavelength of 366 nm.     

新型超支化聚(酰胺-酯)的制备及表征

以二异丙醇胺和六氢化苯二甲酸酐为原料,合成AB_2型单体(DH)。二异丙醇胺过量,利用DH和过量的二异丙醇胺在共沸带水剂二甲苯中进行缩聚反应,合成新型超支化聚(酰胺-酯);同时利用傅立叶红外光谱和化学滴定法对DH和超支化聚(酰胺-酯)进行表征,并对超支化聚(酰胺-酯)的相对分子量分布、溶解性能进行研究。实验结果表明:合成的超支化聚(酰胺-酯)具有较高的分子量,M_n高达42769g/mol,多分散性指数在1．28～1．60之间,呈现很窄的分子量分布;合成的超支化聚(酰胺-酯)具有良好的溶解性能,能溶于醇类、酮类、四氢呋喃等极性溶剂;相对线形高分子,合成的超支化聚(酰胺-酯)具有较低的黏度,体系中含40%的超支化聚(酰胺-酯)仍能全部溶解,且黏度仅为6．61mPa·s。     

超支化聚(胺-酯)的合成及在皮革中的应用

以三羟甲基丙烷为中心核分子,N,N-二羟乙基-3-胺基丙酸甲酯为合成单体,在对甲苯磺酸催化下,采用一步法合成了一系列新型超支化聚(胺-酯)复鞣剂(G1、G2和G3),并用红外(IR)光谱、核磁共振(1H-NMR)和羟值测定对其结构进行了表征,结果表明,合成的超支化聚(胺-酯)化学结构与设计的分子结构一致。将其用作皮革复鞣剂,相对传统复鞣剂的复鞣效果,经超支化聚(胺-酯)复鞣后的皮革在抗裂强度和透气性等方面的性能都有明显的提高,且随着代数的增加,效果更加明显。     

Effect of grafted polymer species on particle monolayer structure at the air-water interface

We have studied poly(methyl methacrylate)-grafted(PMMA) particle monolayer systems at the air-water interface. In previous papers, we reported that PMMA chains grafted from particles (silica particle and polystyrene latex) were extended on water surfaces. Through observing deposited particle monolayers on substrates using SEM, we have confirmed that PMMA of large molecular weights were either dispersed or arrayed in structure with long inter-particle distances approximately 500 nm. In contrast, low molecular weight PMMA were observed to aggregate upon deposition. We speculated that the difference in morphology in deposited particle monolayers would be attributed to the affinity between the grafted polymer and the substrate. To examine the effect of this affinity three new polymer-grafted silica particles were synthesized with a fairly high graft density of about 0.14 approximately 0.43 nm(-2). As well as PMMA-grafted silica particles (SiO2-PMMA), poly(2-hydroxyethyl methacrylate) and poly(t-butyl methacrylate)--grafted silica particles (SiO2-PHEMA and SiO2-PtBuMA) were also prepared and subjected to pi-A isotherm measurements and SEM observations. These pi-A isotherms indicated that polymer-grafted silica formed monolayer at the air-water interface, and the onset area of increasing surface pressure suggests that the polymer chains are extended on a water surface. However, the morphology of the deposited monolayer is highly dependent on polymer species: SiO2-PHEMA showed that the dispersed particle monolayer structure was independent of grafted molecular weight while SiO2-tBuMA showed an aggregated structure that was also independent of grafted moleculer weight. SiO2-PMMA showed intermediate tendencies: dispersed structure was observed with high grafted molecular weight and aggregated structure was observed with low grafted molecule weight. The morphology on glass substrate would be explaiened by hydrophilic interaction between grafted polymer and hydrophilic glass substrate.     

Modification of multi-walled carbon nanotubes by plasma treatment and further use as templates for growth of CdS nanocrystals

In this study, we present a novel method for preparing multi-walled carbon nanotubes (MWCNTs) grafted with a poly(2-methacrylic acid 3-(bis-carboxymethylamino)-2-hydroxy-propyl ester) (GMA-IDA)-cadmium sulfide complex (CNTs-G-ICdS complex) through plasma-induced grafting polymerization. The characteristics of the MWCNTs after being grafted with the GMA-IDA polymer were monitored by a Fourier transform infrared (FT-IR) spectroscope. Scanning electronic microscopy (SEM) shows that the amount of GMA-IDA grafted onto the MWCNTs increases with the concentration of GMA-IDA monomer. The complex resulting from GMA-IDA polymer grafting onto the MWCNTs, CNTs-G-I (15%), shows excellent dispersion properties in aqueous solution and has high Zeta potential values over a wide range of pH values, from 2 to 12. Moreover, Raman spectroscopy was used to confirm the successful chemical modification of MWCNTs through the plasma treatment. The chelating groups, -N(CH(2)COO(-))(2) in the GMA-IDA polymer grafted on the surface of the CNTs-G-I, are the coordination sites for chelating cadmium ions, and are further used as nano-templates for the growth of CdS nanocrystals (quantum dots). Moreover, TEM microscopy reveals that the size of the CdS nanocrystals on the CNT surfaces increases with increasing S(2-) concentration. In addition, high resolution x-ray photoelectron (XPS) spectroscopy was used to characterize the functional groups on the surface of the MWCNTs after chemical modification by the plasma treatment and grafting with GMA-IDA polymer.