PICA法合成介孔二氧化硅研究

以硅酸钠为硅源,在酸性条件下,通过尿素和甲醛的缩聚反应,用诱导聚合胶体团聚法(PICA)制备出单分散脲醛/SiO2复合微球,并经高温煅烧制得介孔二氯化硅。通过X射线衍射(XRD)、氮气脱吸附、透射电镜(TEM)和高分辨透射电镜(HRTEM)等手段对介孔二氧化硅进行了表征。结果表明,通过PICA法制得的介孔二氧化硅有序性好,孔径较大、孔壁较厚、孔径分布均匀。     

微球动态涂敷状态实时监测系统的实现

设计一套新型的微球动态涂敷状态实时监测系统。利用QM-1显微望远系统和GDS-50摄影镜头相结合获得位于1.2m处25mm视场内直径为0.2mm~0.5mm的多个微球涂敷时的清晰像,视频处理系统采集微球的像,并用数字图像处理的方法对采集到的图像进行处理,有效区分背景、运动目标和静止目标。一旦发现有微球停止运动给出警告,实现涂敷作业的自动监视。     

Carbonaceous microsphere-based superabsorbent polymer as filler for coating of NPK fertilizer: Fabrication,properties, swelling,and nitrogen release characteristics

Recently, the use of controlled release fertilizers in agriculture has resulted in huge benefits in plant growth and cultivation. Superabsorbent polymer (SAP)-coated fertilizers have the added advantage in retaining water in soil after irrigation and also reduce the nutrient release rate from soil in a controlled manner. This study aimed to produce a nitrogen–phosphorus–potassium (NPK) fertilizer coated with superabsorbent carbonaceous microspheres polymer (SPC) by inverse suspension polymerization method with water-retention and controlled release properties. Two sets of experiments were conducted: (1) three different weight percentages and (2) different materials. NPK coated with SPC showed increasing water-retention ability with respect to carbon microsphere percentages and retains >80% water at the 30th day of experiment compared with pure NPK and NPK coated with SAP. The slow release behavior of all samples was investigated by induced coupled plasma mass spectrometry spectrometry and results showed that NPK coated with SAP and SPC has a low release rate with <50% nutrient release compared with uncoated NPK at the 30th day. The release mechanism kinetics of NPK coated with SAP and SPC were studied based on the Kosmeyer–Peppas model. The mechanisms approached Fickian diffusion-controlled release as the n value for both samples was less than 0.5. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48396.     

生物提取用磁性微球的制备及其性能

磁性微球因其自身兼具高分子微球和磁性粒子的众多特性,广泛应用在细胞分离、固定化酶、靶向药物、分析检测、免疫测定等领域。本文通过化学共沉淀法制备了Fe3O4纳米粒子,并采用分散聚合法对其包覆,得到Fe3O4/SiO2磁性微球。研究结果表明,通过上述方法制备的磁性微球可以快速、有效的提取生物中的RNA,而且最佳的聚合反应温度为80℃。     

Plugging properties and profile control effects of crosslinked polyacrylamide microspheres

In this article, the morphology, particle size, and plugging properties of crosslinked polyacrylamide (CPAM) microspheres were investigated through optical microscopy, scanning electron microscopy (SEM), nuclear‐pore membrane filtration experiments, a micro‐visual model, sandpack experiments, parallel twin‐tube plugging, and oil displacement experiments. The results revealed that the primary particle sizes of the CPAM microspheres ranged from several hundreds of nanometers to 5 μm; however, after the microspheres were fully swelled in water, their sizes increased by approximately five times of their original sizes. As a CPAM microsphere dispersion system had good dispersibility and deformation capabilities, a 1.2 μm nuclear‐pore membrane as well as the deep part of a sandpack tube could be effectively plugged. Consequently, the flow diversion effect was achieved in the vertical and planar directions. When the CPAM microspheres migrated in porous media, they could displace residual oil on the pole wall and water flow channel to realize the synchronization of profile control and coordination and improve recovery efficiency. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43666.     

环氧树脂的增韧

添加一种分相的橡胶粒子到环氧树脂中可增加其破坏韧性。已知的这些改性剂有 Ｃ Ｔ Ｂ Ｎ、微凝胶和核壳粒子等。这些橡胶增韧环氧树脂体系形成海岛结构,增韧的原因是橡胶粒子的撕裂并诱发母体的塑性变形。另一类替代反应性橡胶用于改性环氧的是多种强韧的热塑性塑料,环氧树脂变韧是形成了双连接相结构。综合讨论了改性剂和母体的性质对环氧树脂共混物韧性的影响以及增韧机理。     

MeTHPA/THPA用量比对环氧树脂微球制备的影响

考察甲基四氢苯酐(MeTHPA)/四氢苯酐(THPA)用量比对环氧树脂/MeTHPA/THPA/聚酯共混体系固化物相结构以及环氧树脂微球的影响。结果表明,随着MeTHPA/THPA用量比的增加,环氧树脂/MeTHPA/THPA/聚酯共混体系固化物的环氧树脂分散相尺寸逐渐减小,制得的环氧树脂微球的粒径及其单分散性指数逐渐降低。当使用纯MeTHPA时,制得的环氧树脂微球粒径约为4μm,单分能胜指数为1.155 3。     

磁性螯合树脂制备技术进展

介绍了磁性螯合树脂的结构,重点综述了磁性螯合树脂的制备方法,并分析了其应用前景。     

溶剂热合成多级ZnO微球及其光催化降解苯酚

以乙二醇为溶剂,KAc为助剂,采用溶剂热法合成多级ZnO微球。通过改变反应温度来调控ZnO微球形貌,并对合成的ZnO微球进行XRD、SEM、PL和UV-Vis DRS等表征分析。结果表明,合成的ZnO为六方纤锌矿晶体结构,由短纳米棒自组装成多级微球。在紫外-可见光照射下,ZnO表现出优异的光催化降解苯酚活性,180℃合成的ZnO样品光催化活性明显优于其他温度合成的样品。用0.1 g的ZnO降解100 mL浓度为5 mg·L^(-1)的苯酚溶液,光照150 min降解率达94.5%。多级ZnO微球光催化性能的提高可推测为较窄的禁带宽度(3.08 eV)有利于吸收光子,较小的晶粒尺寸(25.38 nm)、粗糙的表面以及中空结构有利于反应液与催化剂表面的充分接触。此外,由捕获实验证实光催化降解苯酚的机理是羟基(·OH)为主要的活性自由基,在苯酚降解过程中起主要作用。     

葡聚糖接枝型高载量金属螯合介质的制备与性能

对琼脂糖凝胶微球进行烯丙基活化,再接枝葡聚糖分子,考察葡聚糖分子量等因素对葡聚糖接枝过程的影响;以葡聚糖接枝琼脂糖凝胶微球为基质,制备亚氨基二乙酸型金属螯合介质,考察葡聚糖接枝过程对金属螯合介质的孔道结构、流通性能和载量等的影响. 结果表明,分子量20~500 kDa的葡聚糖都能均匀分布于琼脂糖凝胶微球内,葡聚糖接枝量随分子量增加而增大,所制的金属螯合介质形貌、粒径及其分布基本不受影响,且具有更好的流通性能,孔道结构比商品介质Ni Sepharose 6FF更丰富. 葡聚糖接枝的金属螯合介质对带组氨酸标签的乳酸脱氢酶和睫状神经营养因子的载量分别达到19和27 mg/mL,较Ni Sepharose 6FF的载量分别提高26.6%和42.0%.