石蜡聚苯乙烯微球的制备

通过悬浮聚合技术合成了石蜡聚苯乙烯微球，研究了合成过程中引发剂浓度及交联剂用量对微球粒径及其分布的影响。     

乙烯基胶原蛋白微球的制备及其应用

为了得到带有"-C=C-"的胶原蛋白微球,我们使用甲基丙烯酸酐对胶原蛋白改性,再采用乳化交联法将改性胶原蛋白制备成乙烯基胶原蛋白微球(CMAs),并将微球应用到尼龙基材上.研究了CMAs的制备条件,使用傅里叶红外光谱(FT-IR)、扫描电子显微镜(SEM)、激光粒度分析仪等对CMAs和乙烯基胶原蛋白微球/尼龙(Nylo...     

Unusual Formation of ZnCo2O4 3D Hierarchical Twin Microspheres as a High‐Rate and Ultralong‐Life Lithium‐Ion Battery Anode Material

A facile two‐step strategy involving a polyol method and subsequent thermal annealing treatment is successfully developed for the large‐scale preparation of ZnCo₂O₄ various hierarchical micro/nanostructures (twin mcrospheres and microcubes) without surfactant assistance. To the best of our knowledge, this is the first report on the synthesis of ZnCo₂O₄ mesoporous twin microspheres and microcubes. More significantly, based on the effect of the reaction time on the morphology evolution of the precursor, a brand‐new crystal growth mechanism, multistep splitting then in situ dissolution recrystallization accompanied by morphology and phase change, is first proposed to understand the formation of the 3D twin microshperes, providing new research opportunity for investigating the formation of novel micro/nanostructures. When evaluated as anode materials for lithium‐ion batteries (LIBs), ZnCo₂O₄ hierarchical microstructures exhibit superior capacity retention, excellent cycling stability at the 5 A g^?1 rate for 2000 cycles. Surprisingly, the ZnCo₂O₄ twin microspheres show an exceptionally high rate capability up to the 10 A g^?1 rate. It should be noted that such super‐high rate performance and cycling stability at such high charge/discharge rates are significantly higher than most work previously reported on ZnCo₂O₄ micro/nanostructures and ZnCo₂O₄‐based heterostructures. The ZnCo₂O₄ 3D hierarchical micro/nanostructures demonstrate the great potential as negative electrode materials for high‐performance LIBs.     

Charge-Driven Self-Assembled Microspheres Hydrogel Scaffolds for Combined Drug Delivery and Photothermal Therapy of Diabetic Wounds

The treatment of diabetic wound remains a big clinical challenge. Hydrogel that can provide physical barrier and humidity displays amazing potentials for managing the diabetic wounds healing. Herein, a new charge-driven self-assembled microsphere hydrogel scaffold (SMHS) is reported based on an electric charge interaction, by combining use of black phosphorus (BP)-contained chitosan methacryloyl (CS) microspheres with positive charge and basic fibroblast growth factor-contained hyaluronic acid methacryloyl (HA) microspheres with negative charge. The weak charge attraction among microspheres gives the SMHS the injectable characteristic. Due to the existence of BP, near-infrared (NIR) irradiation has obvious effects on the degradation and drug release behaviors of SMHS. Significantly, SMHS that combines the short-term physical (photothermal) intervention and long-term chemical (drug release) intervention may be promising in spatio-temporal regulation of regenerative microenvironment. SMHS with NIR irradiation (SMHS+NIR) can promote cell proliferation, cell migration, angiogenesis and macrophage polarization. Moreover, in diabetic rat skin wounds, SMHS+NIR significantly accelerates the wound healing process by simultaneously inhibiting the inflammatory response, promoting angiogenesis and tissues remodeling. The outcome of this research not only provides a biomaterial for diabetic wounds healing, but also demonstrates a new strategy for designing novel hydrogel-based biomaterials which have the free editing and combination functions.     

喷雾干燥法制备亚微米鞣酸铁/硝胺炸药复合微球及其催化性能

为了研究鞣酸铁催化剂对固体推进剂中常见组分热分解性能的影响,采用超声喷雾干燥法制得三种亚微米复合微球(鞣酸铁(Ta-Fe)/六硝基六氮杂异伍兹烷(CL-20)、鞣酸铁/黑索今(RDX)、鞣酸铁/奥克托今(HMX))。利用扫描电镜(SEM)和粒度分析等方法分别对复合微球的形貌、粒度和组分进行表征。采用差示扫描量热法(DSC)研究复合微球中鞣酸铁对CL-20、RDX、HMX热分解的催化过程及动力学参数的影响。结果表明,鞣酸铁分布均匀,样品均呈球状颗粒,且流散性好,粒度为500~1000 nm;鞣酸铁能有效促进CL-20、RDX、HMX的热分解,使得CL-20、RDX、HMX的热分解峰温分别提前了17.2,8.2,11.5℃,其中鞣酸铁对CL-20的热分解催化效果最佳,Ta-Fe/CL-20复合微球的活化能与原料CL-20相比降低了9.6 kJ·mol……-1。     

脲醛树脂/TiO2复合微球缓蚀剂的制备及性能表征

为降低发射药的烧蚀性,在不引入模板剂和结构导向剂的情况下,控制尿素和甲醛逐步聚合得到一种表面多孔的脲醛树脂微球作为基体,用溶胶-回流法在孔上沉积纳米TiO_2颗粒,形成复合微球作为缓蚀添加剂使用。扫描电镜及粒径分析结果表明脲醛树脂微球表面存在明显的斑驳纳米孔,结合傅里叶红外(FT-IR)和光电子能谱(XPS)分析,确定纳米孔可用于沉积纯度较高的纳米TiO_2,形成的脲醛树脂/TiO_2复合微球粒径分布在7～30μm。热分析结果显示,复合微球中无机组分的含量约为6%,复合微球与发射药具有良好的相容性,不会影响发射药的热分解且有利于提高发射药的热安定性。半密闭爆发器试验证实了复合微球的缓蚀性能,当复合微球相对于发射药的质量占比为3.4%时效果最好,缓蚀效率可达20.5%。该复合材料有望应用于制式发射药改性和新型高能发射药设计。     

Virus‐Tethered Magnetic Gold Microspheres with Biomimetic Architectures for Enhanced Immunoassays

In immunoassays, non‐specific bindings to biosensing surfaces can be effectively prevented by formation of biocompatible and hydrophilic self‐assembled monolayer (SAM) on the surfaces. A thin gold (Au) layer on magnetic microspheres, 15 μm in diameter, enables facile SAM formation and thereby accepts second layer of filamentous virus scaffolds for the immobilization of functional proteins. The merger of the virus and SAM‐Au protected microspheres not only provides exceptionlly dense antibody loading, but also resembles biological cellular structures that enhance ligand‐receptor interactions. Site‐specific biotinylation of filamenous viruses allows formation of free‐standing virus threads (>1.0 × 10¹⁰) on streptavidin‐modified SAM‐Au microspheres. The augmented yield of antibody loading, due to the increased surface to volume ratio, on virus‐modified Au microspheres is confirmed by measuring fluorescence intensities. The bead‐based immunoassays for the detection of cardiac marker proteins exhibit increased sensitivity of virus‐Au microspheres, as low as 20 pg mL^?1 of cardiac troponin I in serum, and extremely low non‐specific adsorption when compared with bare polymer beads. This increased sensitivity due to filamentous morphology and SAM‐Au layer demonstrates the feasibility of merging viruses with non‐biological materials to yield biomimetic tools for the enhanced bead‐based immunoassays.     

铝对自蔓延火焰淬熄法合成空心陶瓷微珠的影响

以自蔓延高温合成技术(SHS)为基础,采用自反应淬熄法研究TiO2+蔗糖,TiO2+蔗糖+Al两种体系下空心陶瓷微珠的反应生成情况。以SEM、XRD、EDS为手段分别测试所得产物的形貌、主要相组成以及微区成分组成。结果表明:TiO2+蔗糖体系所得产物由不规则的块状物质与表面凹凸不平的类球形物质组成;TiO2+蔗糖+Al体系熔射产物全部由表面光滑的球形颗粒组成。球形颗粒为空心结构,主要组成为Al2O3-TiC复相和少量的铝钛合金、AlN以及Ti(C,N)。Al的加入大大改善了空心微珠的生成。     

Enhancing the Stability of Perovskite Quantum Dots by Encapsulation in Crosslinked Polystyrene Beads via a Swelling–Shrinking Strategy toward Superior Water Resistance

Organic/inorganic hybrid lead halide perovskites are promising optoelectronic materials due to their unique structure, excellent properties, and fascinating potential applications in lighting, photovoltaic, etc. However, perovskite materials are very sensitive to moisture and polar solvent, which greatly hinders their practical applications. Here, highly luminescent perovskite–polystyrene composite beads with uniform morphology are prepared via a simple swelling–shrinking strategy. This process is carried out only in nonpolar toluene and hexane without the addition of any polar reagents. As a result, the as‐prepared composite beads not only retain high luminescence but also exhibit superior water‐resistant property. The composites emit strong luminescence after being immersed into water over nine months. Moreover, even in some harsh environments such as acid/alkali aqueous solution, phosphate buffer solution, and Dulbecco's modified eagle medium biological buffers, they still preserve high luminescence. The applications in light‐emitting diodes and cellular labeling agents are also carried out to demonstrate their ultrastability.     

Gelable and Adhesive Powder for Lethal Non-Compressible Hemorrhage Control

Hemostatic powders are widely used in clinical and emergency situations but often exhibit low wet adhesion, cytotoxicity concerns, and do not work well for lethal non-compressible hemorrhage. Here a new kind of gelable and adhesive powder (GAP) is developed, which integrates chitosan microspheres (CM), tetra-armed poly(ethylene glycol) amine (Tetra-PEG-NH₂), and tetra-armed poly(ethylene glycol) succinimidyl succinate (Tetra-PEG-SS). Upon application to the wound site, the macroporous CM can rapidly absorb the interfacial liquids, and meanwhile, the hydrated GAP turns into hydrogel (crosslinking between Tetra-PEG-SS and CM/Tetra-PEG-NH₂) with stable and robust adhesion to the wet tissue though covalent bonding. The in vitro and in vivo results suggest that the GAP with optimized formulation exhibits strong tissue adhesive, high burst pressure, and enhanced blood clotting ability, as well as excellent biocompatibility and on-demand removal properties. A significantly improved hemostatic efficacy is demonstrated in the rat liver, spleen, and femoral artery injury models compared to that of the CM, commercial fibrin glue, and Yunnan Baiyao (YB). The GAP can also halt the severe bleeding from pig visceral organs. Overall, the proposed GAP has many advantages including good biocompatibility, rapid and effective hemostasis, low cost, and ease of use, making it as a promising hemostat for lethal non-compressible hemorrhage control.