纳米四氧化三铁磁性微粒的表面有机改性

通过液相共沉淀法制备了纳米四氧化三铁溶胶，利用油酸对纳米粒子体进行表面改性和萃取实验，获得油酸包覆的四氧化三铁微粒。采用FT—IR和高分辨透射电镜对改性后的纳米粉体进行结构和形貌的表征。研究结果表明油酸与四氧化三铁纳米粒子间存在化学键结合。油酸对纳米四氧化三铁微粒进行改性，并且对纳米粒子进行包覆，使外表面形成保护层阻止粒子团聚，改性后的四氧化三铁微粒与有机物具有良好的相溶性，采用表面改性显著改善了纳米四氧化三铁微粒的性能指标。     

血液过滤用熔喷PBT非织造布紫外辐照接枝改性研究

研究了血液过滤用熔喷PBT非织造布的紫外辐照气相接枝改性方法。通过实验选择了丙烯酸(AAc)为接枝单体 ,探讨光照时间、预辐照时间、单体温度、引发剂浓度、氮气压力对接枝率和表面润湿张力的影响 ,结果得到最佳的紫外辐照接枝条件为 :室温下 ,光距 2 0cm ,预浸 10min ,二苯甲酮 (BP) 0 .0 37mol/L ,冲入单体的氮气流量 87.5h/L ,反应时间 30min。PBT非织造布AAc紫外辐照接枝后表面润湿张力可以达到 85mN/m左右 ,且表面润湿张力随接枝率的提高而增加     

改性催化裂化催化剂研究进展

对催化裂化催化剂的活性组分Y型分子筛的脱铝改性及抗重金属污染改性方法和改性后的含Y型沸石的性能进行了详细介绍。重点介绍了经特殊改性的催化裂化催化剂在脱硫、多产柴油及多产丙烯等方面的用途,指出应在现有技术基础上重点开发性能更为优良的多用途催化裂化催化剂。     

改性丙烯酸-环氧树脂纳米乳液的制备及应用

介绍了水性丙烯酸-环氧树脂纳米乳液的制备及其在油罐防腐工程中的应用。讨论了亲水侧链聚乙二醇相对分子质量大小对涂膜性能的影响以及乳化剂各组分的用量对乳液粒径的影响。     

Modification of phenol–formaldehyde resol resins by lignin,starch, and urea

Lignin‐based chemicals, starch, and urea were used as modifiers for phenol–formaldehyde resol resins. The effects of the addition stage of the modifiers used in the synthesis of the resins and the type of modification reagent on the structures of the resins and their molar masses and reactivities were investigated. The modifications with corn starch and lignin promoted condensation; this was verified by increased molar masses and high ratios of methylene bridges to the sum of free ortho and para aromatic groups with respect to the corresponding reference resin without a modification reagent. The later the modifier was added to the resin condensation mixture, the more methylene bridges were formed with respect to the amounts of free ortho and para aromatic groups. In addition, when urea or wheat starch was added in the later condensation stage, the final condensation also reached high stages. The modifications with lignosulfonate and starch, as well as the early addition of urea, enhanced p–p′ bridge structures. The lowest condensation stage and, therefore, the highest reactivity were found when wheat starch was added with the starting reagents. The curing heat of the wheat‐starch‐modified resins decreased according to the deferred addition point of starch. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 582–588, 2003     

Acrylonitrile-based copolymer membranes containing reactive groups: Surface modification by the immobilization of biomacromolecules

Asymmetric membranes fabricated from poly(acrylonitrile-co-maleic acid) (PANCMA) were immobilized with heparin and/or insulin to improve their surface properties. These biomacromolecule-immobilized PANCMA membranes were prepared by the amination of the membrane surface with ethylenediamine, followed by the reaction of the amino groups with heparin and/or insulin in the presence of 1-ethyl-3-(3-dimethyl amidopropyl) carbodiimide. The surface-modified membranes were analyzed by X-ray photoelectron spectroscopy to confirm the immobilization of the biomacromolecules. Morphological changes on the membrane surface and in the cross section were characterized by scanning electron microscopy. The surface hydrophilicity and hemocompatibility of the studied membranes were evaluated on the basis of water contact angle, platelets adhesion and cell attachment measurements. It was found that, after the immobilization of the biomacromolecules, the water contact angle and the amount of adhered platelets and macrophages on the membrane decreased significantly when compared with the nascent ones, indicating the improvement of surface hydrophilicity. Furthermore, the heparin immobilized membrane showed the best hemocompatibility among the corresponding membranes studied.     

介孔材料化学改性研究进展

综述了介孔材料化学改性目的，改性原理以及改性方法。介孔材料的化学改性包括对材料骨架的修饰以及对孔道表面的功能化，介孔材料表面自由硅醇键、双羟基硅醇踺是化学改性的基础，利用疏水性物质改性可以提高材料的水热稳定性，引入催化活性组分可以提高催化性能，利用具有特定官能团的硅烷偶连剂改性，则能够实现特殊的目的。详述了化学改性方法，包括元素取代法、共价键移植法和有机硅烷偶连法。元素取代法是对分子筛骨架结构的修饰，共价键移植法是一种不引起孔道结构破坏且非常有效的骨架修饰方法，对介孔材料表面进行有机硅烷偶连剂法修饰改性主要有两种途径：即共沉淀法和后移植法。     

丙烯酰胺改性蜜胺甲醛树脂的絮凝性能研究

合成了丙烯酰胺改性三聚氰胺（蜜胺）甲醛树脂，研究了其絮凝性能，利用烧杯澄清试验法，考察了酸碱条件，絮凝剂投加量和静置时间对絮凝性能的影响。实验证明：酸性条件，絮凝剂投加量为50mg/L，静置时间为20min时改性树脂的絮凝效果最好。并且与不同絮凝剂进行了浊度去除效果比较。     

Ce和La改性固体超强酸S2O82-/ZrO2-SiO2催化剂合成及其酯化性能研究

以Zr(NO₃)₄·5H₂O和Na₂SiO₃·9H₂O为原料,利用共沉淀法制备前驱体,浸渍添加稀土Ce和La,一定温度焙烧后制得掺杂稀土S₂O₈^2-/ZrO₂-SiO₂固体超强酸。通过XRD、FT-IR和SEM对催化剂进行表征,以硬脂酸的酯化合成反应为探针,考察制备条件对催化剂性能的影响以及催化剂的重复使用率。结果表明,相对于未改性的S₂O₈^2-/ZrO₂-SiO₂催化剂,添加了Ce或La的固体超强酸酯化催化活性及重复使用性能均有提高。     

大分子表面改性剂在聚合物表面的富集行为

简述了大分子表面改性剂添加到聚烯烃基体中时接触介质的诱导作用和聚烯烃基体结晶的异质排斥作用及其相对分子质量、链节的柔顺性和与基体的相容性对其表面富集的影响。提出大分子表面改性剂设计合成的基本原则:化学结构和使用环境相匹配、憎水基功能团和亲水基功能团相适应、使用效率和功能持久性相平衡。介绍了大分子表面改性剂合成的主要方法。