聚丙烯酰胺包覆磁性纳米凝胶的光化学法制备及其机理研究

以丙烯酰胺为单体，N，N’-亚甲基双丙烯酰胺为交联剂，采用光化学方法在水溶液体系中制备了聚丙烯酰胺（Polyacrylamide，PAM）包覆的磁性纳米凝胶，用傅立叶变换红外光谱（Fourier transform infrared spectroscopy,FTIR），光子相关光谱（Photo correlation spectroscopy,PCS）和电子自旋共振（Electron spin resonance，ESR）波谱对聚丙烯酰胺磁性纳米凝胶进行了表征。研究了磁性纳米凝胶粒径随反应时间、单体浓度、交联剂浓度的变化规律，并探索了聚丙烯酰胺磁性纳米凝胶的包覆机理。     

粒径可控的羧基化磁性纳米凝胶的合成

采用光化学原位聚合法制备了粒径可控的羧基化磁性纳米凝胶,研究了滴加单体的量、体系pH、光照时间和链转移剂等对羧基化磁性纳米凝胶粒径的影响。     

光聚合一步可控合成表面氨化的核壳型超顺磁性纳米凝胶及其表征

用部分还原共沉淀结合离心分离合成超顺磁性Fe3O4纳米粒子,以其为核,N-（2-氨乙基）甲基丙烯酰胺盐酸盐N-（2-Aminoethyl）methacrylamide,AEM·HCI）为单体,N,N＇-亚甲基双丙烯酰胺（MSA）为交联剂,采用光聚合原位一步合成粒径可控的表面氨化的超顺磁性核壳型Fe3O4纳米凝胶。探索了单体、交联剂量及光照时间对纳米凝胶粒径的影响,并用动态光散射仪（DLS）、TEM、FTIR、TGA、UV、多功能磁测量仪等表征了纳米凝胶的粒径、粒径分布、形貌、结构、磁响应性及稳定性。结果表明：改变单体、交联剂量及光照时间可得到不同粒径、粒径分布均匀的超顺磁性纳米凝胶;与Fe3O4纳米粒子相比,纳米凝胶的磁饱和强度略有降低,但其高的Zeta电位使其稳定性大大提高。     

光化学制备用于链亲和素固定的胺基磁性纳米凝胶的研究

本工作提出制备胺基磁性纳米凝胶的一种改进方法。在含有烯丙基胺的Fe304水分散液中,运用紫外光辐照引发烯丙基胺原位聚合,一步法制备了聚烯丙基胺磁性纳米凝胶（Polyallylamine magnetic nanogels,PAA,MNGs）。透射电子显微镜（Transmission electron microscope,TEM）和光子相关光谱（Photo correlation spectroscope,PCS）表征了PAA-MNG的形貌和粒径分布;热重分析（Thermogravimetric analysis,TGA）确定了磁性成分的含量,振动样品磁强计（Vibrating sample magnetometer,VSM）测试表明其呈现超顺磁性。利用表面的伯胺基,PAA-MNGs可以方便地偶联蛋白等生物大分子。链亲和素（Streptavidin,SA）经1-乙基3-（3-二甲氨基）碳化二亚胺盐酸盐和N-羟基琥珀酰亚胺活化后可以共价固定在PAA—MNGs上,得到链亲和索包覆的纳米磁球（Streptavidin—coated magnetic nanoparticles,SA—MNPs）。使用探针生物素对硝基苯酯（Biotin P—nitrophenyl ester,BNPE）通过光谱检测证实了SA-MNPs的生物素结合能力。表明PAA—MNGs适合于作为载体偶联蛋白等生物大分子,并可能用于生物技术领域的诸多方面。     

聚N-异丙基丙烯酰胺包覆Fe3O4磁导向纳米粒子的制备和表征

选择N-异丙基丙烯酰胺(N-isopropylacrylamide,NIPAM)为单体,N,N′-亚甲基双丙烯酰胺(Methylenebisacrylamide,MBA)为交联剂,用辐射化学方法合成了具有温敏的PNIPAM包覆Fe3O4磁导向纳米粒子。研究了NIPAM单体浓度、交联剂MBA用量、不同光照时间及温度对核壳结构磁性纳米粒子粒径的影响,发现在一定范围内随单体NIPAM浓度的增加、交联剂MBA浓度的减小、光照时间的增加,聚NIPAM包覆Fe3O4核壳结构纳米粒子的粒径增大。在25—39℃温度范围内PNIPAM包覆Fe3O4核壳结构纳米粒子具有最低临界溶解温度特性(Lowercriticalsolutiontemperature,LCST）。以SEM和动态激光光散射仪(PCS)对该核壳结构纳米粒子粒径进行测定,表明辐射化学方法合成的核壳结构纳米粒子比较均匀。     

磁性纳米微粒的制备方法及其在放射免疫分析中的初步应用

采用化学共沉淀法合成水溶性正癸酸包覆的Fe3O4磁性纳米微粒,并以此为核心物理吸附羊抗兔IgG制备磁性纳米第二抗体,作为磁性分离载体用于放射免疫分析中。用光子相关光谱仪与透射电镜测定了磁性纳米微粒的粒径大小、粒径分布和多分散度等。研究了羊抗兔IgG包被磁性纳米微粒的包被介质的pH、羊抗兔IgG用量和包被时间等制备条件对磁性纳米微粒二抗免疫反应结合能力和非特异结合的影响。结果表明：化学共沉淀法制得的Fe3O4平均粒径约为10-20nm,吸附羊抗兔IgG后其平均粒径为1000nm左右,并可用于放射免疫分析中。提示羊抗兔IgG可通过物理吸附的方法固定在磁性纳米微粒上,其优点是制备方法简便、省时和成本低,在放射免疫分析中具有磁性分离的方便性,具有较大的医学应用价值。     

氧化锡纳米晶气凝胶制备及其表征

介绍一种低体密度、高表面积、具有纳米量级骨架和晶粒尺寸的块状多孔氧化锡(SnO2)气凝胶的制备方法。场发射扫描电子显微镜（FESEM）表明,气凝胶是由大量纳米粒子堆积而成的三维多孔材料。高分辨透射电子显微镜（HRTEM）表明,气凝胶的骨架粒子由平均粒径为2～3nm的纳米微晶构成。N2吸附表明,气凝胶具有较高的比表面积,约为355.65m2/g,通过该方法计算出的气凝胶的骨架颗粒粒径为2.4nm,与HRTEM结果吻合较好。     

聚α-甲基苯乙烯的可控合成

以α-甲基苯乙烯（α-MS）为原料，采用阴离子聚合方法合成了聚α 甲基苯乙烯均聚物（PAMS），并采用静态光散射凝胶色谱（LS/GPC）对分子量（M_n，M_w）及分子量分布（M_w/M_n）进行了测定。结果表明，采用阴离子聚合能够实现对PAMS分子量可控，且达到极窄的分子量分布(M_w/M_n＜1.1）的目的。     

以PS为模板的RF气凝胶空心微球制备

采用聚苯乙烯(PS)空心微球为模板,间苯二酚/甲醛(RF)为前驱体溶液,邻苯二甲酸二丁酯为分散剂,以界面聚合反应为基础合成PS-RF核壳双层球,用丙酮去除模板,制得RF空心微球.分别采用红外光谱、X光显微分析、透射电镜(TEM)、N2吸附-脱附和原子力显微分析,对RF空心微球成分、形貌、孔径、表面粗糙度等进行表征.结果表明:RF为单层空心球壳,具有典型的气凝胶多孔结构,由粒径约为10 nm且粒度分布较为均匀的纳米粒子构成,平均孔径约为17 nm,球形度和同心度达到95%以上,表面光洁度小于10 nm,达到了快点火靶的基本要求.     

智能纳米凝胶的合成及其生物医学应用

本文首先阐述了高分子微凝胶材料的研究概况，智能纳米微凝胶的研究进展及其应用前景；然后系统分析了微凝胶的合成方法及其特点，智能纳米高分子凝胶的合成方法及粒径控制；最后详细介绍智能纳米栽药体系的特点，靶向和释放机制及其在基因工程治疗上的应用。     

^188 Re labeled MPEG-modified superparamagnetic nanogels：preparation and preliminary application in mice

Superparamagnetic poly（acrylamide） magnetic nanogels produced via photochemical method have been developed. After Hoffmann degradation of carbonyl, the nanogels with amino groups, or poly（acrylamide-vinyl amine） magnetic nanogels, were also obtained. And the magnetic nanogels were further modified by methoxy poly（ethylene glycol） （MPEG） for higher dispersibility and stability. The MPEG-modified magnetic nanogels were characterized by X-ray diffraction （XRD）, photo correlation spectroscopy （PCS） and scanning electron microscopy （SEM）, respectively. The MPEG-modified magnetic nanogels were labeled by ^188 Re radiopharmaceuticals and intravenously injected into tails of mice in the presence and absence of a 0.5 T external magnetic field targeted on the bellies. The radioactivity distribution was monitored in vivo. In the absence of magnetic field, the radioactivity was mainly distributed in liver, spleen, kidney, stomach and lung. In the presence of the magnetic field, the radioactivity was mainly accumulated on the targeted point, verifying the magnetically targeted character.     

窄粒径分布磁性纳米凝胶的光化学制备和表征

Modified magnetic nanoparticles have gained considerable attention because of their great potential applications in biomedical fields, such as protein and enzyme immobilization, bioseparation, immunoassays and biosensor etc. In recent years, great efforts have been made in developing targeted drug carriers by use of magnetic nauogels.Magnetic nanogels of common interest are ferromagnetic magnetite (Fe3O4) coated with cross-linked polymer nanogels. Several methods have been developed to prepare magnetic micro- and nanogels, such as inverse microemulsion polymerization, emulsion polymerization and other methods. In this paper, we propose an alternative approach to synthesize poly (N-isopropylacrylamide) (PNIPAM), polyacrylamide (PAM) superparamagnetic nauogels via photochemical reactions at room temperatures in au emulsion- and initiator-free aqueous system.Temperature-dependent magnetic nanogels weresynthesized by using NIPAM as monomer[1]. The PNIPAM-modified magnetic nauogels have the character of lower critical solution temperature (LCST),and its particle size is sensitive to environmental temperature. Polydispersity index of the magnetic nauogels modified with PNPAM are lower than 0.25(Fig. 1). The magnetic nauogels modified with PAM were prepared by using acrylamide (AM) as monomer.After Hoffinann elimination, nanogels with amino groups were also obtained[2]. Particle size of all the nauogels can be controlled by controlling the reaction time, the monomer concentration and the cross-linker concentration.High zeta potential of the magnetic nauogels were measured by PCS, and their core-shell structure and regular morphology were confirmed by TEM, AFM and SEM, respectively. The nauogels with amino groups were covalently radiolabeled with 188Re complex in vitro.In conclusion, a new approach to produce magnetic nanogels via photochemical reaction has been developed.Narrow size distribution magnetic nanogels with temperature-sensitive shell and amino groups have been synthesized successfully. This suggests promising potential applications for targeted drug carriers.     

18-冠-6/LA/Fe3O4复合磁性纳米粒子的制备及其吸附性能研究

Fe₃O₄磁性纳米粒子（MNPs）比表面积大、吸附能力强,且在外磁场作用下易于液固分离,冠醚具有对铀酰离子选择性配位的能力。本研究制备了兼具两者特点和优势的18-冠-6/LA/Fe₃O₄复合磁性纳米粒子。其结构经红外（IR）、扫描电镜-X射线能谱（SEX/EDX）、振动样品磁强计（VSM）、热综合分析仪（TGA）进行表征,表明18-冠-6/LA/Fe₃O₄复合磁性纳米粒子的粒径为12～23 nm,饱和磁化强度为56.34 emu/g。用制得的复合磁性纳米粒子对溶液中铀酰离子进行初步吸附实验,在选定的条件下,平衡吸附率达95%,操作方法快速简便,吸附后的磁粒子可方便地进行富集和回收。     

微波非热效应对有机硫化合物结构的影响

为探究微波辐照脱除煤中有机硫的作用机理以及影响程度,通过核磁共振氢谱、红外光谱和激光共聚焦显微拉曼光谱技术,研究了微波非热效应对有机硫模型化合物结构性能的影响。红外光谱测试说明,微波辐照有机硫化合物存在非热效应并影响化学键的键能分布、基团的振动强度和稳定性,但仅限于分子的极化机制,不会破坏分子中原有的化学键也不会生成新的化学键和基团;核磁共振氢谱揭示非热效应影响了模型化合物分子内部的电子云密度分布和磁环境,对含硫化合物产生的双重极化作用既可改变微观的电子或原子极化,也可改变分子固有偶极矩的取向;显微激光拉曼光谱证明非热效应可有效极化含硫键,使之振动强度减弱,从而有助于有机硫的微波辐射脱除。     

高能电子束辐射对碳纤维表面结构的影响

利用激光拉曼光谱（Raman Spectroscopy）、X射线光电子能谱（XPS）、原子力显微镜（AFM）和X射线衍射（XRD）对高能电子束辐射前后的表面结构进行分析，结果表明，随着剂量的增加，碳纤维表面石墨微晶尺寸增大。碳原子在高能电子束的作用下离位，使表面棱角超于圆滑，当剂量较大时，处于石墨片层边缘的活性碳原子重新增多。碳纤维表面极性官能团受辐射介质产生的活性种的影响，同时在高能电子束辐射下激活，发生自淬灭反应和解离反应，前者占优势时，高价态的C＝O增多，反之，C－O基团增多。在试验范围内，高能电子束对碳纤维的晶型结构无影响。     

Preparation of silica-coated CdSe QDs for cell imaging applications

CdSe quantum dots (QDs) were prepared at room temperature by E-beam irradiation of the solution, using ethylene diamine tetraacetic acid as stabilizer. Silica-coated CdSe QDs were made in water-in-oil microemulsion, while amino groups were introduced synchronously onto the nanoparticles by copolymerization of 3-aminopropyl- trimethoxysilane and tetraethyl orthosilicate. The results of TEM imaging, fluorescent spectroscopy and photostability tests show that the QDs are of uniform spherical size (200±8 nm), monodispersity, and high fluorescence and photostability.