明胶纳米颗粒的制备

以B型明胶为原料,戊二醛为交联剂,通过改进的两步去溶剂法制备了较小粒径(约100 nm)的明胶纳米颗粒(Gelatin nanoparticles,GNPs),考察了分散体系浓度、去溶剂化试剂、交联剂用量对GNPs粒径的影响。结果表明:降低明胶在二次分散体系中的浓度,制得的GNPs的尺寸更小且分布均匀。残留的去溶剂化试剂丙酮需去除,因为它会使GNPs分散性变差。在明胶质量浓度为8 g/L的分散液中,当戊二醛加入量为4.5%(以明胶的质量为基准,下同)时,即可制得稳定的GNPs,其粒径为50~150 nm,PDI约为0.14,Zeta电位绝对值大于30 m V。AFM和TEM测试结果表明:GNPs呈光滑球形,为边缘部分比核心更为疏松的非均质结构。     

用于稳定Pickering乳液的氨基化明胶纳米颗粒的制备

以氨基化改性的B型明胶为原料,通过二次去溶剂法可制得具有良好单分散性(PDI≈0.068)的氨基化明胶纳米颗粒(Aminated gelatin nanoparticles,AGNPs),其粒径约为240 nm,表面带正电荷(ζ≈35 mV),并考察了制备过程中溶液pH对AGNPs粒径以及分散性的影响。结果表明:当pH≈4.0时,制备的AGNPs粒径较小(≈240nm),分散较为均匀。SEM、AFM及TEM测试结果表明:AGNPs为一种粒径窄分布的球形纳米颗粒;相比明胶纳米颗粒(Gelatinnanoparticles,GNPs),AGNPs刚性结构特点增强,且质地较为均匀。颗粒表面润湿性测试结果显示,AGNPs的三相接触角(θow=67?±5?)比GNPs(θow=31?±6?)显著增大,表明AGNPs的表面疏水性有所增强。以AGNPs为稳定剂制备的水包油(O/W)型Pickering乳液4℃下储存9个月未出现分层,表现出较高的稳定性。     

明胶海绵吸水性能的研究

分别以甲醛、戊二醛为交联剂,制备了明胶海绵支架。考察了不同交联剂对明胶海绵吸水性能的影响。结果表明,戊二醛为交联剂制得的明胶海绵的吸水率明显高于甲醛。     

聚β—羟基丁酸戊酸酯（PHBV）为载体的药物缓释微球的制备

泽用ＰＨＢＶ为载体,采用乳化溶剂蒸发法制备黄体酮的缓释微球进行了研究。结果表明,当选用明胶为乳化剂时,可以制得分散、较圆且表面光滑的微球;明胶浓度及搅拌转速不但影响微球的粒径而且影响药物包埋率;药物的包埋率还受ＰＨＢＶ在氯仿相中浓度、药物加入量以及制备温度的影响。研究微球体外释放行为发现,当ＰＨＢＶ在氯仿中浓度为０．１（ｗ／ｖ）、黄体酮加入量为ＰＨＢＶ质量的０．０６（ｗ／ｖ）、温度为４０℃时,制得     

非离子表面活性剂微乳液中苯乙烯聚合

在烷基葡萄糖苷（APG）／苯乙烯／水三元体系形成的WinsorI型多相微乳液介质中，通过聚合反应制得粒径37nm、单分散（P=0．17〈0．2）聚苯乙烯颗粒，聚合过程中没有出现分层现象。研究了温度、引发剂类型以及无机盐浓度对产物粒径和相对分子质量的影响，并比较了一次性加料和连续加料进行聚合对粒径的影响。结果表明，在水溶性引发剂、高温（60-70℃）条件下制得的是小粒径（37nm）、单分散的聚苯乙烯颗粒，且随着无机盐浓度增大，聚合物颗粒粒径变大（40hm），多分散度变小（P=0．05）。     

超增溶自组装原位合成ZSM-5纳米分子筛

采用超增溶胶团法制备纳米ZSM-5分子筛。考察体系水含量、乳化剂用量、晶化温度和焙烧温度等因素对合成分子筛产品的粒径、晶体形貌、孔径、孔容和比表面积等的影响，并采用BET、XRD和TEM等手段对其进行表征。结果表明，制备纳米ZSM-5分子筛的最佳条件：n（H₂O）∶n（SiO₂）=90,乳化剂（RHP）质量分数为10%,晶化温度180 ℃,焙烧温度500 ℃。制得的粒子平均粒径（50～70） nm,大多数粒子为球形，粒径分布较窄，呈单分散且微粒不易团聚。     

烷基多苷微乳液中苯乙烯聚合的研究

在烷基多苷（APG）／苯乙烯／水三元体系O／W微乳液中,选用水溶性K2S2O8作为引发剂,制得小粒径（35．4nm）、单分散（P=0．180〈0．2）聚苯乙烯颗粒。研究了苯乙烯、过硫酸钾、烷基多苷以及NaCl质量浓度对产物粒径和多分散度的影响。结果表明：聚苯乙烯随苯乙烯的增加颗粒粒径变大（43．8nm）;随过硫酸钾的增加颗粒粒径变大（37．9nm）,多分散度变小（P=0．153）;随烷基多苷的增加颗粒粒径变小（33．4nm）,而多分散度变大（P=0．195）;随NaCl的增加颗粒粒径变大（45．6nm）。微乳结构的转变点对产物有重要的影响。     

5-氟尿嘧啶/明胶的制备及释药性能

以A型明胶为原料、5-氟尿嘧啶为模型药物、异丙醇为凝聚剂,采用单凝聚法制备了5-氟尿嘧啶/明胶纳米载药颗粒(5-FU/GNPs),并测定了纳米颗粒的粒径分布、载药量、体外缓释效果和抗肿瘤性能。结果表明:5-FU/GNPs表面形态良好,分散均一,平均粒径为(75.1±2.1)nm,载药量为23.5%±1.9%;5-FU/GNPs具有良好的缓释性能,Higuchi方程对微球的体外药物释放情况拟合度较高。四甲基偶氮唑蓝实验表明:5-FU/GNPs对胃癌细胞(SGC7901)的抑制率可达71%。     

溶剂热法合成硫化镉材料实验研究

以硫脲、九水硝酸镉为原料,乙二醇为溶剂,聚乙烯吡咯烷酮（PVP）为分散剂,聚丙烯酰胺（PAM）或N,N-二甲基甲酰胺（DMF）为生长调节剂,采用溶剂热法成功制备了硫化镉纳米材料。探究了分散剂与生长调节剂对溶剂热法合成硫化镉纳米材料的影响。研究表明,仅以PVP为分散剂制得的硫化镉颗粒呈现规则的球形且粒度均匀,小球粒径约为500 nm;以PVP为分散剂,DMF为生长调节剂,两者协同作用抑制了硫化镉的生长,得到的硫化镉颗粒粒度均匀,小球粒径约为250 nm;以PVP为分散剂,PAM为生长调节剂,两者协同作用得到的硫化镉颗粒呈现规则的球形且粒度均匀,小球粒径约为125 nm。X射线衍射（XRD）表征结果表明,合成的硫化镉是纯相硫化镉,生长调节剂具有粒径“倍增效应”。     

磁响应交联糖化酶聚集体的制备及催化特性

提出了一种采用羧基磁性纳米粒子制备杂化磁响应交联酶聚集体（M-CLEAs）的方法。表面羧基修饰的约10 nm的磁性纳米粒子与酶分子表面的氨基位点通过静电相互作用,形成复合物,在磁场作用下可将磁性纳米粒子-酶复合物从溶液中分离,经戊二醛交联即形成M-CLEAs。传统的表面氨基修饰的磁性纳米粒子与酶需在沉淀剂作用下,从溶液中分离,而后采用戊二醛共交联,而本方法无须沉淀剂,过程更为简化。以糖化酶为对象,对该过程的影响因素（交联时间、pH、酶浓度、戊二醛浓度等条件）进行了探索,并对制得的M-CLEAs的酶学性质进行了较为详细考察。结果表明,最优制备条件为：酶浓度1 mg·ml^-1,磁流体浓度10 mg·ml^-1,戊二醛浓度0.25%（质量体积比）,在pH 6.0下交联反应6 h,最终载酶量可达80 mg·g^-1、比活为50 U·mg^-1。制得的固定化酶pH稳定性、热稳定性和储存稳定性均显著改善,可实现糖化酶重复使用10次,仍保留接近60%的酶活。     

Compatibility and mechanical properties of gelatin-filled polybutylene succinate composites

Gelatin nanoparticles (GNPs) with small size (200 nm) have been prepared by two-step solvent removal method using glutaraldehyde as crosslinking agent. The formation mechanism and characteristics were determined by Fourier transform infrared (FTIR), atomic force microscopy, and transmission electron microscopy. Polybutylene succinate/gelatin (PBS/GEL) and polybutylene succinate/nanogelatin (PBS/GNPs) composites by solvent hybridization were prepared. The dispersion of GEL/GNPs in the composites was observed by scanning electron microscopy, and the hybrid mechanism of GEL, GNPs, and PBS was explored. The results of FTIR and XPS indicated that the ─OH of GNPs was easier to obtain hydrogen bond with PBS. The swelling test showed that the swelling degree of PBS/GEL, PBS/GNPs reached 253 ± 8.65% and 308 ± 10.3% due to their good compatibility. Compared with pure PBS, especially when the ratio of PBS:GNPs was 1:0.75, the crystallinity of PBS/GNPs composites reached 36.43 ± 5.7%, the elongation at break and tensile strength were 49.0 ± 2.94% and 33.3 ± 2.62 MPa, respectively. Overall, GNPs have played an active role in the heterogeneous nucleation of PBS matrix. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48881.     

Nanoparticle‐loaded UV‐blocking contact lenses

We have developed a novel approach of incorporating UV‐blocking features into contact lenses by dispersing nanoparticles into the lenses. The nanoparticles are prepared by controlling polymerization dynamics using chain terminating and chain transfer agents. A theoretical model is developed to predict the effect of various formulation parameters on the particle size. This approach can produce UV‐blocking nanoparticles of controlled size below 10 nm in diameter with close to 10% conversion. The model predictions for the mean size are in reasonable agreement with the experimental data. The nanoparticles are cleaned and loaded in silicone hydrogel contact lenses by soaking the lenses in a solution of particles in ethanol and acetone. Lenses loaded with about 6% particles w/w in the hydrated lens block sufficient UV light to be classified as Class 1 blockers. The nanoparticles are retained in the lens during soaking in phosphate buffered saline (PBS) and are stable to sterilization by autoclaving. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42495.     

Radiation synthesis and characterization of poly(vinyl alcohol)/poly(N-vinyl-2-pyrrolidone) based hydrogels containing silver nanoparticles

A series of PVA/PVP based hydrogels at different compositions were prepared by gamma irradiation. The gel fraction degree of swelling were investigated. Highly stable and uniformly distributed silver nanoparticles have been obtained onto hydrogel networks. The morphology and structure of (PVA/PVP) hydrogel and dispersion of the silver nanoparticles in the polymeric matrix were examined by scanning electron microscopy (SEM) and infrared spectroscopy (FT-IR), respectively. The formation of silver nanoparticles has been confirmed by ultraviolet visible (UV–vis) spectroscopy. A strong characteristic absorption peak was found to be around 420 nm for the silver nanoparticles in the hydrogel nanocomposite. The X-ray diffraction pattern confirmed the formation of silver nanoparticles with average particle size of 12 nm. The diameter distribution of silver nanoparticles was determined by dynamic light scattering DLS. Transmission electron microscope (TEM) showed almost spherical and uniform distribution of silver nanoparticles through the hydrogel network and the mean size of silver nanoparticles ranging is 23 nm. The good swelling properties and antibacterial of PVA/PVP-Ag hydrogel suggest that it can be a good candidate as wound dressing.     

Studies on preparation and properties of PAA/gelatin core-shell nanoparticles via template polymerization

Taking advantage of the simultaneous polymerization and self-assembly between the components during the template polymerization, narrowly distributed nanoparticles with core-shell structure were prepared at high concentrations via polymerizing acrylic acid (AA) in aqueous solution of template gelatin. The influences of various polymerization parameters such as medium pH, concentration, and ratio of AA/gelatin were systematically investigated, which indicates that the size and structure of the nanoparticles can be adjusted by changing the reaction conditions. The nanoparticles are stimuli-responsive: the nanoparticles' size increases when increasing or decreasing pH value from about 2.8 while it first decreases slightly and then increases monotonically as salt concentration increases. Also, the nanoparticles exhibit a stronger salt-resistance as compared with those prepared by dropping method. The structure of the nanoparticles was further locked by selectively crosslinking gelatin with glutaraldehyde. The size and swelling capacity of the nanoparticles decrease with the increase of crosslinking degree.     

Synthesis and photochromic property of nanoparticles with spiropyran moieties via one-step miniemulsion polymerization

Summary  Photochromic nanoparticles with spiropyran moieties were prepared by a facile one-step miniemulsion polymerization. The nanoparticle dispersion was obtained by mixing the monomers, spiropyran-containing molecules and hydrophobe, dispersing them into an aqueous solution with surfactant, subjecting the dispersion to ultrasonification and polymerizing the monomers by using a water soluble initiator. The shape and size of the nanoparticles was determined with the atomic force microscope (AFM) and dynamic light scattering (DLS), and the determined average diameter of the nanoparticles ranges from 30 nm to 60 nm. The absorption and fluorescence spectra for the nanoparticles dispersions reveal that the spiropyran molecules were successfully incorporated in the polymer nanoparticles. Moreover, the nanoparticle dispersions were found to exhibit enhanced photo-reversibility, photo-stability and relatively fast photo-responsive property compare to the same species in aqueous solution.     

乳化法明胶亚微米粒子的制备

以A型明胶为原料,石蜡油为油相,采用乳化化学交联方法制备了明胶亚微米粒子. 用扫描电子显微镜(SEM)观察了明胶亚微米粒子的形貌和粒径. 研究了影响微球粒径的多种因素,包括明胶溶液浓度、乳化搅拌速度、乳化温度、乳化剂和固化剂. 结果表明,采用戊二醛为固化剂、增加明胶的浓度、提高乳化搅拌速度、使用混合性的乳化剂都有利于降低明胶粒子的粒径. 此外,对制备工艺进行了优化,并在7000 r/min左右高速搅拌的条件下,得到了成球性较好的粒径约为450 nm的明胶亚微米粒子.     

Controlled assembly of graphene shells encapsulated gold nanoparticles and their integration with carbon nanotubes

Controlled growth and uniform patterning of graphene/carbon shells encapsulated gold nanoparticles (GNPs) on silicon wafer or on high curvature carbon nanotubes (CNTs) is reported here. This was achieved by utilizing patterned gold nanoparticles with controlled sizes (∼30–600 nm) via gold film dewetting process. Surface-oxidized and patterned nanoparticles were used as sacrificial catalysts for the chemical vapor deposition (CVD) growth of graphene/carbon shells. The shell morphological evolution and thickness as well as surface migration of nanoparticles during the CVD process were studied as a function of the gold nanoparticles size. Reduced surface migration and coalescence was observed for gold nanoparticles after the CVD growth and this was attributed to the initial formation of graphene/carbon shells as well as stable dispersion of the dewetted gold nanoparticles. It is proposed that graphene/carbon shell growth was controlled by Ostwald’s ripening, surface gold oxide, and reducing CVD growth environment. Furthermore, complex heterostructures based on CNTs coated with GNPs were fabricated by dewetting Au films on CNTs and followed by surface oxidation and CVD growth steps. CNTs successfully survived multiple processing steps and selective growth of graphene shells around Au nanoparticles was achieved and studied using microscopic and spectroscopic methods.     

Application of the dry‐spinning method to produce poly(ε‐caprolactone) fibers containing bovine serum albumin laden gelatin nanoparticles

We designed and manufactured a polymeric system with combined hydrophilic–hydrophobic properties by loading gelatin nanoparticles (GNPs) containing bovine serum albumin (BSA) into poly(ε‐caprolactone) (PCL) fibers. Our ultimate goal was to create a device capable of carrying and releasing protein drugs. Such a system could find several biomedical applications, such as those in controlled release systems, surgical sutures, and bioactive scaffolds for tissue engineering. A two‐step desolvation method was used to produce GNPs, whereas PCL fibers were produced by a dry‐spinning method. The morphological, mechanical, and thermal properties of the produced system were investigated, and the distribution of nanoparticles both inside and on the surface of the fibers was examined. The effect of the particles on the biodegradability of the fibers was also evaluated. In vitro preliminary tests were performed to study the release of BSA from nanoparticle‐laden fibers and to compare this with its release from free nanoparticles. Our results indicate that the distribution of particles inside the fibers was quite homogeneous and only a few of them were present on the surface. The presence of the particles in the fibers did not affect the thermal properties of the PCL polymer matrix, although it created voids that affected the degradation characteristics so the PCL fibers favored faster erosion compared to the plain fibers. Preliminary results indicate that the release from GNP‐laden fibers occurred much more slowly compared to that in the free GNPs. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44233.     

蒙脱石和聚乙烯吡咯烷酮界面作用对零价铁纳米颗粒制备及其性能调控的影响与机理

以蒙脱石为载体,水溶性聚合物聚乙烯吡咯烷酮（PVP）为稳定剂,通过硼氢化钠化学液相还原高铁离子制备了零价铁纳米粒子。采用扫描电镜、透射电镜、X射线衍射分析、X射线光电子能谱分析等手段对所得铁粒子进行了表征。结果表明,所得铁粒子大致呈球状形貌,尺寸较均匀,平均粒径约为34nm,在蒙脱石颗粒外表面分散良好。该铁粒子内核为零价铁,表面包覆铁氧化物外壳,外壳厚度保持3nm左右,有效抑制了零价铁内核的深度氧化。PVP自身及其与蒙脱石颗粒通过界面作用形成的层离结构均可对铁粒子起到分散作用,使所得铁粒子较之蒙脱石和PVP未参与制备的铁粒子粒径减小、分散程度提高。     

用离子液体聚合物制备和稳定金纳米粒子

以1-甲基咪唑和4-乙烯基苄氯制备了聚〔1-甲基-3-(4-乙烯基苯甲基)咪唑氯〕(PMVBIC),并用1HNMR和FTIR进行了结构表征。然后在PMVBIC的水溶液中,用NaBH4还原HAuCl4制备金纳米粒子,通过UV-Vis光谱和TEM分析发现,PMVBIC能有效稳定金纳米粒子,而且PMVBIC和NaBH4的浓度会明显影响金纳米粒子的粒径、形状和分散性,当m(PMVBIC)∶m(HAuCl4)=34.5∶1,n(NaBH4)∶n(HAuCl4)=2∶1时,可以制得粒径约7nm、均匀分散的球形金纳米粒子,室温存放150 d无明显变化。