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。     

Fe_3O_4/聚丙烯酸/CdS复合粒子的光化学制备及光催化性能

采用光引发丙烯酸聚合的方法对Fe3O4纳米粒子进行表面改性,制备了羧基功能化的Fe3O4/聚丙烯酸复合纳米粒子(Fe3O4/PAA);以Fe3O4/PAA为磁核,以硫酸镉和硫代硫酸钠为原料,采用光化学方法制备Fe3O4/聚丙烯酸/CdS复合粒子(Fe3O4/PAA/CdS),并借助红外光谱、X射线粉末衍射、透射电子显微镜、荧光光谱和振动样品磁强计对其进行表征。结果表明,核-壳结构的Fe3O4/PAA/CdS为表面粗糙的球形粒子,平均粒径为155 nm,具有发光性能和准超顺磁性。Fe3O4/PAA/CdS在有机染料罗丹明B的降解实验中显示出良好的可见光催化活性,可以借助磁铁在2 min内从溶液中完全回收。     

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.     

γ射线辐照合成γ-Fe2O3/聚苯乙烯磁性复合微球

结合^60Coγ射线辐照与分散聚合，分别通过两步法和一步法，在常温常压下，成功地合成了γ-Fe2O3／聚苯乙烯(γ-Fe2O3／PSt)磁性复合微球，并对复合微球的形成机理进行了探讨。用透射电子显微镜(TEM)、电子衍射(ED)、X射线衍射(XRD)、付里叶变换红外(FTIR)光谱对样品进行表征和研究。实验结果表明，产品为多个γ-Fe2O3纳米粒子均匀地分散于PSt微球中的γ-Fe2O3／PSt磁性复合微球，体系中的丙烯酸(AA)对磁性复合微球的形成起到了非常重要的作用。     

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。     

Au/Fe3O4磁性复合粒子的光化学制备

用紫外光辐照含有纳米 Fe3O4磁流体的氯金酸和聚乙烯醇的水溶液,制备了 Au/Fe3O4磁性复合粒子,并用紫外.可见光谱、X射线衍射和透射电镜对其进行了表征.磁性复合粒子中Au纳米粒子具有面心立方结构,其等离子共振吸收峰分布较窄,说明金纳米粒子的粒径分布较均匀.TEM表明该复合粒子具有团簇状结构,由许多Au和Fe3O纳米粒子构成,尺寸介于70-230 nm范围.对照实验表明聚乙烯醇是Au纳米粒子与Fe304之间复合的必需媒介,据此提出了生成团簇状Au/Fe3O4磁性复合粒子的可能机制.     

乳液微封装技术制备聚苯乙烯空心微球

介绍了乳液微封装技术制备不同直径空心聚苯乙烯微球的工艺技术,着重研究了表面活性剂、电解质、水溶性聚合物对多重乳液的稳定性、微球的直径以及微球表面光洁度的影响。在选定的实验参数下,制备得到直径150～3000μm,壁厚0.8～15μm,表面粗糙度Ra约为4nm,微球同心度≥95%的空心聚苯乙烯微球。     

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。     

三氧化二铬-聚苯乙烯单层复合靶丸的制备

在聚苯乙烯(PS)中掺杂金属元素可为微球打靶过程提供诊断信息。以Cr2O3-PS复合材料为原料，采用微封装法通过两步乳化制备出掺杂Cr2O3的PS复合靶丸，Cr2O3在球壳内掺杂均匀，表面粗糙度低于30nm。     

固相微球放免分离剂的研制

采用丙烯酰胺丙烯酸为单体的共聚反应,生成带有羧基官能团的载体微球;用化学偶联法,使微球的羧基与抗体的氨基共价结合,形成牢固而稳定的固相抗体微球;用1-乙基-3-(3-二甲基丙氨基)碳二亚胺为联接剂,制备出T_3。T_4固相一抗及固相二抗。对该固相抗体微球的悬浮性、牢固性、沉淀的结实性以及高温下的稳定性等做了测定。在放射免疫分析中,使用固相微球分离剂,具有非特异结合低(2～3％),批内变异<5％,批间变异<15％,且操作简便、迅速、稳定等优点,是一种先进的分离技术。     

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。     

冠醚包覆聚苯乙烯磁性颗粒的合成、表征及其对锶离子的吸附性能

为建立应用磁性颗粒快速分离低水平~(90)Sr的方法,分别以沉淀法合成Fe_3O_4纳米颗粒,微乳聚合法合成磁性聚苯乙烯-二乙烯苯颗粒(Pst-DVB@Fe_3O_4),并将4,4’(5’)-二叔丁基二环己基-18-冠-6(DtBuCH18C6)通过物理作用包覆在Pst-DVB@Fe_3O_4颗粒表面,最终生成一种新型的核-壳结构的DtBuCH18C6包覆的聚合物磁性颗粒(DtBuCH18C6@Pst-DVB@Fe_3O_4)。采用扫描电镜、红外光谱、X射线光电子能谱等方法对颗粒的形貌、结构、表面元素组成及含量进行分析。用于分离水溶液中Sr~(2+)的批实验结果表明,Sr~(2+)的吸附量随着pH值而增加,而在pH=11和pH=13之间急剧上升,温度升高,其吸附量增加。吸附动力学模型结果表明,Sr~(2+)在DtBuCH18C6@Pst-DVB@Fe_3O_4表面的吸附更接近于其和Sr~(2+)之间形成络合物的单层化学吸附过程,符合Langmuir模型。在优化的条件下其最大吸附容量为2.62 mg/g。     

Effects of ion irradiation on cobalt nanocomposite

The effects of ion irradiation of 3-dimensional arrays of Co nanoparticles were investigated. Arrays were obtained by electron beam deposition of 15 Co/SiO₂ bilayers 0.5 and 20 nm thick, respectively. The Co layers consist of Co nanoparticles 3.2 nm in diameter with a standard deviation of 16%. Irradiation was carried out using combinations of 150 kV Ar²⁺ and 90 kV Ar⁺ ion bombardments with a Ar⁺:Ar²⁺ fluence ratio of 1:4. The effects of ion irradiation were followed by Rutherford backscattering, measurements of hysteresis loops at 5 K and of temperature-dependent field-cooled (FC) and zero-field-cooled (ZFC) measurements of the magnetic susceptibility. A decrease of the peak temperature in the ZFC curve for displacements per atom (DPA) up to 1.1 was observed. Irradiation also induces progressively lower coercivity values. The Co particles showed a remarkable high resistance to ion irradiation, surviving damage up to 33 DPA.     

Cu2O nanoparticles:Radiation synthesis,and photocatalytic activity

<正>Cu_2O nanocrystals were synthesized by irradiating an aqueous solution of CuSO_4·5H_2O(1.25g),polyvinyl alcohol(PVA,0.8 g),and isopropanol(3.1 mL).The products were characterized by powder XRD,TEM and SEM. Methyl orange degradation under visible light using the Cu_2O nanocrystals as catalyst was studied by UV-Vis absorption method.The results show that the products are nanocrystals of pure Cu_2O.Morphology and size of the nanoparticles are affected by the irradiation dose and pH value of the initial solution.Octahedral Cu_2O nanocrystals of 116 nm in size can be obtained at the initial pH of 8.0 and 280-kGy irradiation.The nanocrystals have excellent catalytic activity for photodegradation of the methyl orange solution bubbled at the air-flow rate of 750 mL·min~(-1),due to the large {111} facets of octahedral Cu_2O particles.     

同步辐射圆二色谱法研究Fe3O4纳米颗粒对细胞色素C结构的影响

四氧化三铁纳米颗粒(Fe3O4-NPs)在生物医学领域有着广泛的应用。通过同步辐射真空紫外圆二色谱(SRCD)和紫外可见(UV-Vis)吸收谱技术研究了Fe3O4纳米颗粒的粒径(10 nm和40 nm)对细胞色素C(Cyt c)结构的影响。结果表明,随着Fe3O4-NPs颗粒物浓度的增大,Cyt c在408 nm处的吸光度值逐渐下降。SRCD结果显示Cyt c与Fe3O4-NPs作用后,蛋白的α螺旋含量减少,β折叠含量增加;Fe3O4-NPs与Cyt C的作用强度具有尺寸依赖性,小尺寸的Fe3O4-NPs作用更为明显。     

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。     

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.     

Radiochemical synthesis of silver nanoparticles onto textile fabrics and their antibacterial activity

This paper presents a new technique for synthesizing silver nanoparticles immobilized on textile fabrics using a radiochemical process. In this process, the irradiation of a high-energy electron beam on an aqueous solution containing silver ions induces a reducing reaction that forms metallic silver nanoparticles. Small Ag particles of about 2–4 nm were observed together with relatively large particles of more than 10 nm. These nanoparticles are firmly immobilized on the surface of a support textile fabric without the need for any binder or surfactant. The amount of silver nanoparticles immobilized was found to depend on the water content of the support textile fabric, suggesting that the silver ions are reduced not only by radiochemical species generated by the radiolysis of water, but also by radiochemical species generated in the irradiated support fabric itself. The silver nanoparticles that were immobilized on the support textile fabric exhibited an excellent antibacterial activity across a wide antibacterial spectrum, even after a durability test involving washing the fabric 100 times.     

快速响应PNIPA／Fe3O4复合凝胶辐射制备与性能研究

采用化学共沉淀法制备了四氧化三铁粒子,以N-异丙基丙烯酰胺（NIPA）、N,N-亚甲基双丙烯酰胺（MBA）和聚乙二醇（PEG）为原料,以60Coγ,射线为放射源,辐照聚合制备了多孔PNIPA／Fe3O4复合水凝胶,并对其温度敏感性、平衡溶胀率进行了表征。研究发现：磁性四氧化三铁纳米粒子在凝胶中分散均匀;凝胶具有明显的温度敏感性;致孔剂的添加提高了水凝胶的平衡溶胀率,多孔复合水凝胶失水率达96％,比普通磁性水凝胶失水率提高了约76％;致孔剂的添加使复合凝胶的最低临界相转变温度由34℃升高至37℃左右。