Characterization of highly hydrophobic coatings deposited onto pre-oxidized silicon from water dispersible organosilanes

The formation and quality of highly hydrophobic coatings deposited from water dispersible organosilanes onto pre-oxidized single crystal silicon were studied using atomic force microscopy, ellipsometry, dynamic contact angle measurements and electrochemical impedance spectroscopy (EIS). Highly hydrophobic films of a commercially available water dispersible silane and two different cationic alkoxysilanes were prepared by dip coating. It was found using atomic force microscopy that, in general, the structure of these highly hydrophobic films is a continuous film with some particulates attributed to bulk polymerization of the precursor molecule in water. Film defects were quantified using EIS by the value of charge transfer resistance at the hydrofluoric acid/silicon interface. Potential applications of this type of coatings include reduction/elimination of stiction in micro-electromechanical systems, contact printing in materials microfabrication, inhibition of corrosion and oxidation, prevention of water wetting, lubrication and protein adsorption.     

相对分子质量和磺化度对木质素磺酸钠农药分散剂性能的影响

测定了美国Meadwestvaco公司的VSI系列的9种木质素磺酸钠(简称木钠)的结构特征,发现木钠的相对质量分数很高,基本都在90%以上。以各木钠为分散剂,制备烯酰吗啉水分散粒剂(WG),并测定其热贮前后应用性能,结果发现,较高的相对分子质量(简称分子量)和磺化度的木钠,有利于提高WG的悬浮率。D80木钠作分散剂的WG热贮后悬浮率最高,为95.89%。进一步考察了WG的分散稳定性,结果发现,在磺化度相近时,提高木钠分子量有利于提高WG悬浮液的分散稳定性;而分子量相近时,木钠的磺酸基对WG分散稳定性影响较小。D80木钠的烯酰吗啉WG悬浮液静置15min才出现沉淀,沉淀层厚度为0.47mm,稳定性最好。     

Synthesis of water dispersible magnetite nanoparticles in the presence of hydrophilic polymers

Water dispersible magnetite nanoparticles (Fe₃O₄) were synthesized by thermal decomposition of iron (III) acetylacetonate (Fe(acac)₃) in the presence of carboxylic acid-terminated poly(ethylene glycol) (mPEG acid), poly(vinyl alcohol) and NH₂-containing polyether. Crystal structure was investigated using X-ray diffractometry (XRD) and it showed that the as-synthesized particles had high crystallinity with distinct lattices. Particle size of the nanoparticles was investigated using XRD (15.32 nm), transmission electron microscopy (18.8 nm) and photo correlation spectroscopy (32 nm) techniques. Vibrating sample magnetometry indicated that magnetite nanoparticles exhibited superparamagnetic behavior at room temperature. Influence of each functional group on magnetic properties of the particles was also examined. These magnetite nanoparticles remained dispersible in aqueous dispersions with only 5% particles aggregating after 1 month of preparing.     

高浓度90%莠去津水分散粒剂的研制

介绍了高浓度90%莠去津水分散粒剂(WG)的制备,并确定了优惠配方,简述了该剂型的特点、配方组成、加工工艺、贮存稳定性以及性能测定。试验结果表明该产品的各项指标符合水分散性粒剂的要求,如悬浮率在90%以上,崩解时间在1min以内,在(54±2)℃下贮存4周后的分解率小于5%,且产品的各项指标均符合水分散粒剂的要求。     

水可分散多异氰酸酯的研制

采用多异氰酸酯与聚乙二醇反应，将表面活性链段引入到多异氰酸酯分子链中，制得水可分散多异氰酸酯（WDP）组分，并借助于相反转技术研究了聚乙二醇的相对分子质量和用量对WDP组分分散性能的影响，较为系统地介绍了水性聚氨酯涂料的固化成膜机理，研究了水性聚氨酯涂料的固化和适用期。     

高效液相色谱法测定唑嘧磺草胺的含量

唑嘧磺草胺水分散粒剂中有效成分测定,采用高效液相色谱法,使用以250×4.6mm(id)SPHER IC18为填充物的不锈钢柱,以乙腈-水-二甲基甲酰胺-四氢呋喃-85%磷酸为流动相,苯甲酰胺为内标,在265nm波长进行分离和测定。平均回收率为99.71%~99.89%,标准偏差和变异系数分别为0.113和0.141。     

Synthesis of CaWO4：Eu3＋ phosphor powders via ethylene glycol route and its optical properties

Eu3+ doped CaWO4 with tetragonal system were prepared at comparatively low temperature (125 ?C) in ethylene glycol medium. The phosphor was further investigated by X-ray diffractometer (XRD), photoluminescence spectrophotometer (PL), Fourier transform infra red (FT-IR) spectroscopy and transmission electron microscopy (TEM). XRD analysis indicated a decrease in the unit cell volume of CaWO4 with increasing Eu3+ ion concentration. It indicated the homogeneous substitution of Ca2+ ions in CaWO4 by the Eu3+ ions. TEM images showed that the particle size ranged from 20 to 200 nm and it could extend the application of the nanoparticles. The photoluminescence study showed that the intensity of electric dipole transition (5D0→7F2) at 614 nm dominated over the magnetic dipole transition (5D0→7F1) at 592 nm. The optimum concentration of Eu3+ for the highest luminescence was found to be 20 at.%. The as prepared samples were found to be dis-persible in water and methanol.     

可再分散乳胶粉的研究进展

可再分散乳胶粉具有产品质量高、易于贮存,包装、运输、施工方便,抗冻及抗微生物污染能力强等众多优点,是近年来极力推广的一种新型建筑材料添加剂,应用日益广泛.论文介绍了可再分散乳胶粉的种类及制备过程,综述了可再分散乳胶粉的作用机理、应用及存在的问题,并据此对可再分散乳胶粉的研究方向进行了展望.     

水分散苎麻麻骨饼的制备及其性能

为探索苎麻麻骨治理重金属废水的工业化应用可行性,首先,利用激光粒度仪、SEM和FTIR等表征手段对苎麻麻骨微粒进行微观表征,探明了苎麻麻骨的微观结构;然后在此基础上,将苎麻麻骨微粒与环境友好型天然润湿剂、黏结剂及崩解剂混合,按一定工艺流程加工成水分散苎麻麻骨饼（WDRSC）,在配方筛选过程中,测试了各种助剂质量分数对WDRSC性能的影响,并对苎麻麻骨与WDRSC吸附重金属Cu2+和Cd2+的能力进行了比较。结果显示:苎麻麻骨为具有多孔隙结构的天然物质,表面具有大量的吸附位点和官能团;当WDRSC配方中麻骨、润湿剂、黏结剂和崩解剂的质量比为75:13:2:10时,WDRSC入水后能迅速被水润湿（润湿时间小于60 s）并自动崩解（崩解时间小于60 s）,60 s内悬浮率达80%左右,各项性能均符合水分散颗粒剂的要求;润湿剂、黏结剂和崩解剂均能不同程度地影响WDRSC的相关性能;与苎麻麻骨相比,WDRSC对Cd2+与Cu2+的去除率分别提高了11%和4%。所得结论表明将苎麻麻骨制成WDRSC具有运输和使用方便、成本低廉、制作工艺简单且吸附后废渣处理方便等优点,为苎麻麻骨规模化利用的可行方法。      

合成壳聚糖/DNS杂化材料及吸附重金属Pb~（2＋）的性能研究

通过丁二酸酐、可分散的纳米二氧化硅与壳聚糖脱水合成了壳聚糖/DNS杂化材料。通过FTIR和热重分析等方法对杂化材料进行了表征。FTIR表明壳聚糖与DNS通过丁二酸酐桥连为一个高分子聚合物;热重分析结果表明,杂化材料的热性能有较大提高。考察了壳聚糖及杂化材料微粒吸附Pb2＋时吸附条件对吸附率的影响,结果表明,其吸附最佳条件为：pH=5,吸附时间为120 min,吸附剂的投加量为0.1 g。杂化材料的吸附率达49.16%,与壳聚糖同样具有甚至更强的吸附Pb2＋的能力。