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1.
非离子型聚氨酯表面活性剂的合成及其性能   总被引:3,自引:0,他引:3  
以4,4’-二苯甲烷二异氰酸酯、蓖麻油、聚乙二醇和甲醇为原料,通过逐步聚合得到一种新型的表面活性剂.并用红外光谱对其结构进行了表征。对该表面活性剂在水相中表面活性进行测试,结果表明,所制备出的聚氨酯表面活性剂的临界胶束浓度约为10^-3mol/L,水溶液的最低表面张力可达30mN/m.  相似文献   

2.
在表面活性剂(聚乙烯吡咯烷酮、木质纤维素、聚乙二醇)的保护下,制备了纳米级的氯化银溶胶,借助于分光光度计和TEM分析仪研究了纳米氯化银在不同温度条件下的稳定性,同时对纳米氯化银的变色进行研究,用X射线衍射研究了纳米氯化银溶胶变色以后溶胶体系的变化。  相似文献   

3.
采用动态激光光散射、GPC、环境扫描电镜研究了羧甲基纤维素系列高分子表面活性剂在盐水溶液中的胶束形态,发现盐水溶液中,高分子表面活性剂形成较均一的球形胶束,盐既能使CMC链段卷曲,胶束尺寸减小,又可破坏氧乙烯链段与水的亲合作用,使胶束聚集。分子量相近的共聚物体系形成大小相近的胶束粒子,且胶束分子量分布也基本相同  相似文献   

4.
采用动态激光光散射、GPC、环境扫描电 羧甲基纤维素系列高分子表面活性剂在盐水中溶液中的胶束形态,发现盐水溶液中,高分子表面活性剂形成较均一的球形胶束,盐既能使CMC链段卷曲,胶束尺寸减小,又可破坏氧乙烯链段与水的亲合作用,使胶束聚集,分子量相近的共聚物体系形成大小相近的胶束粒子,且胶束分子量分布也基本相同。  相似文献   

5.
制备条件对溶胶-乳化-凝胶法制备TiO2颗粒尺寸的影响   总被引:2,自引:0,他引:2  
用溶胶-乳化-凝胶法合成了纳米TiO2光催化剂粉末,探讨了制备条件:表面活性剂浓度、溶胶的pH值、水含量以及煅烧温度对其粒径的大小和粒度分布的影响.研究表明:当表面活性剂达到临界胶束浓度时颗粒尺寸小且分布较均匀,当溶胶pH为8~9,水的浓度达到0.5mol/L后颗粒尺寸基本保持不变.此外,煅烧可以改善TiO2粉体的结晶度,促使由无定型向锐钛矿型以及金红石型转变,煅烧过程中,TiO2颗粒的形貌变化过程为:成型球体→棒状→球体→变形球体.  相似文献   

6.
本文用滴体积法测定了对硼酸结晶有显著影响的非离子表面活性剂在硼酸溶液中不同温度条件下的表面张力,求得了对应的临界胶束浓度。根据质量作用定律,推出了表面活性剂胶束化时的热力学模型并对其热力学性质进行了计算和讨论。  相似文献   

7.
应用自动表面张力仪测量了对硝铵结晶有显著影响的阴阳离子复合表面活性剂和在硝铵溶液中不同温度下的表面张力,求得了对应的临界胶束浓度(CMC).根据质量作用定律,得出了表面活性剂胶束化时的热力学模型,并对其热力学性质进行了计算和讨论。  相似文献   

8.
复合表面活性剂在硝铵溶液中胶束化热力学性质研究   总被引:1,自引:0,他引:1  
应用自动表面张力仪测量了对硝铵结晶有显著影响的阴阳离子复合表面活性剂和硝铵溶液中不同温度下的表面张力,求得了对应的临界胶束浓度(CMC)。根据质量作用定律,得出了表面活性剂胶束化时的热力学模型,并对其热力学性质进行了计算和讨论。  相似文献   

9.
应用萃取法,通过调整萃取溶剂比例,增加萃取次数对三次采油用石油磺酸盐中的未磺化油和含有无机盐的活性剂进行充分分离。石油磺酸中的无机盐采用《GB/T6366—92表面活性剂中无机硫酸盐的测定》中规定的方法测定。用含有无机盐的活性剂的量减去无机盐含量,得到石油磺酸盐的活性物含量。  相似文献   

10.
新型非离子水性聚氨酯表面活性剂的制备及性能   总被引:1,自引:0,他引:1  
采用甲苯-2,4-二异氰酸酯(TDI)、蓖麻油和聚乙二醇(PEG)等为主要原料,通过逐步聚合得到一种新型非离子水性聚氨酯表面活性剂,并利用红外光谱对其结构进行了表征。实验结果表明,当蓖麻油∶TDI∶PEG-4000=1∶9∶11时,采用依次加入蓖麻油、TDI、PEG的加料方式,能够合成得到综合性能较好的非离子水性聚氨酯表面活性剂。对该表面活性剂在水相中的表面活性进行了测试,结果表明,所制得的非离子水性聚氨酯表面活性剂的临界胶束浓度约为22 g/L,水溶液的最低表面张力可达53 mN/m。  相似文献   

11.
以聚乙烯醇(PVA)与聚乙二醇(PEG)共混,并以正硅酸乙(酯TEOS)和钛酸四丁酯(TBT)为无机前驱体,采用溶胶-凝胶法制备了不同(SiO_2-TiO_2)含量的PVA-PEG/SiO_2-TiO_2杂化溶胶,陈化后用提拉法制得杂化纤维.研究了杂化溶胶的可纺性,并使用IR、光学显微镜、UV-Vis和TG对杂化纤维的结构与性能进行了研究.结果表明:随硅钛摩尔比的增加或随有机相中PEG/PVA质量比的增加,溶胶的可纺性变好;有机相与无机相之间通过化学键连接;纤维直径为50μm左右;TiO_2的引入增加了其抗紫外性,杂化纤维的耐热性优于纯PVA-PEG.  相似文献   

12.
Four different hybrid organic-inorganic materials based on TiO2-SiO2 matrices with organic additives and doped with rare-earth metal ions (III) from the group of europium, cerium, terbium, neodymium, dysprosium and samarium, were synthesized by sol-gel method. Tetraethyl orthosilicate, titanium (IV) isopropoxide and organic compounds, such as butyl acrylate, butyl methacrylate, ethyl acetoacetate, ethylene glycol dimethacrylate, ethyl acetate, propylene carbonate, organic solvents and certain inorganic salts were used in the synthesis. The inorganic part of the sols, which were used in the synthesis of all the hybrid materials, was prepared separately and then the organic parts were added. The materials obtained were aged for three weeks at room temperature and then heated in an electric oven for three hours at temperatures of 80 °C?C150 °C. Scanning electron microscopy equipped with energy dispersive X-ray spectroscopy (SEM/EDX); X-ray diffraction (XRD); Fourier transform infrared spectroscopy (KBr technique); 29Si magic-angle spinning nuclear magnetic resonance; and fluorescence spectroscopy were used for the examination of morphology, microstructure and luminescence properties, respectively. Photoluminescence properties with relatively intense narrow emission lines of Tb, Eu, Dy, Nd, Sm respectively to the RE-ions doping, were observed for all the hybrid materials.  相似文献   

13.
添加剂对PAN中空纤维超滤膜影响规律研究   总被引:13,自引:2,他引:11  
根据有机添加剂和无机添加剂在超滤膜形成过程中所发挥作用的不同,分别选择不同分子量的聚乙二醇和无机盐LiCl,ZnCl2,Mg(ClO4)2为添加剂,观测其对聚丙烯腈中空纤维超滤膜性能影响,同时发现,采用复合添加剂在膜孔径进行调节,可以得到孔径小,孔隙率高的中空纤维超滤膜。  相似文献   

14.
有机硅溶胶-凝胶涂层是指以烷基烷氧基硅烷为前驱体通过溶胶-凝胶技术制备的涂层。有机硅是分子水平上的有机-无机杂化分子,因此有机硅溶胶-凝胶涂层兼具了有机材料和无机材料的性能,并且能通过合理的调控有机和无机成分来获得所需的性能。其热稳定、耐刮擦性与无机材料的结合性能明显高于普通的有机材料,柔韧性与有机材料的结合性能明显高于一般的无机涂层。近年来,这种新型的、具有特殊性能的涂层被广泛研究用来保护金属材料(如铝、铁、镁、铜基材料)。介绍了有机硅溶胶-凝胶涂层涉及的基本反应、硅烷在金属表面上的成键机理以及在不同金属上的应用等方面的研究进展,并展望了有机硅溶胶-凝胶涂层应用前景及未来的研究方向。  相似文献   

15.
Poly(ethylene glycol) (PEG)/SiO2-CaO-P2O5 hybrid xerogels were prepared using a room temperature sol-gel process. The advantage of this hybrid material over conventional composites is the molecular scale interactions between the bioactive inorganic components and the biodegradable organic components. Since PEG was added into the sol when the hydrolysis of tetraethoxysilane occurred, the molecular chain of PEG was penetrated into the SiO2 networks to form a semi-IPN structure. Due to the excellent biocompatibility and aqueous solubility of PEG molecules, as well as the bioactivity of the inorganic components, the biological and mechanical properties of this hybrid xerogel exhibit great potential for bone regeneration applications. The formation of hydroxyapatite was observed when the xerogel was immersed into simulated body fluid, demonstrating good bioactivity of the hybrid. The cell toxicity test also demonstrated that the hybrid material is suitable for the proliferation of MC3T3-E1 cells. Thus, the PEG/SiO2-CaO-P2O5 hybrid xerogel has great potential to meet the demands of bone regeneration materials.  相似文献   

16.
Bao L  Mahurin SM  Haire RG  Dai S 《Analytical chemistry》2003,75(23):6614-6620
A surface-enhanced Raman scattering (SERS) substrate containing silver particles was prepared by an acid-catalyzed sol-gel method. Silver nitrate was first doped into the sol-gel film followed by chemical reduction of the silver ions with sodium borohydride to produce silver particles. This silver-doped sol-gel substrate exhibits strong enhancement of Raman scattering from adsorbed uranyl ions with a detection limit of 8.5 x 10(-8) M, which is comparable to existing methods of uranyl detection such as spectrophotometry, fluorometry, and a SERS method based on ligand-modified solution silver colloids. However, in the present method, no preconcentration steps, chromogens, or complexing ligands are needed. Compared with the SERS method using Ag colloidal sols, the silver-doped sol-gel film has the advantage that the silver particles trapped in the sol-gel matrix are much more stable than Ag colloids in liquid media. Furthermore, porous silica sol-gel materials are known to have affinities toward many inorganic and organic molecules. The enhanced adsorption affinities could also lead to the increased SERS sensitivity. The performance of the new silver-doped sol-gel substrate was evaluated with uranyl ions and compared to that of a SERS substrate based on silver-coated silica beads prepared by vacuum deposition. The detection limit for the silver-doped sol-gel film was 104 times lower than that for the silver-coated silica beads. The sol-gel substrate was further used to obtain, for the first time, the surface-enhanced Raman spectrum of neptunyl ions in dilute aqueous solutions.  相似文献   

17.
《Materials Letters》2006,60(17-18):2086-2089
The present study attempts to incorporate acrylate-based polymers into ordered lamellar organic–inorganic nanocomposite thin films composed of alternating Poly(TPGDA)/ITO layers. The films were prepared by dip-coating from a homogeneous solution containing the soluble inorganic metal salts (InCl3·4H2O and SnCl2·2H2O), surfactant, cross-linkers, organic monomers, and initiators, thus leading to composite lamellar nanocomposite materials through evaporation-induced self-assembly method. The final polymer/ITO nanocomposite thin film was obtained by a separate free-radical polymerization step, initiated by UV exposure. Structures and composition of the films were characterized using FTIR, XRD, UV–Vis spectrophotometer and TEM. The results indicated that the films were composed of organic and inorganic layers with orderly interlaced arrangement.  相似文献   

18.
For control of the pore size distribution of silica gel, the gel was prepared using the sol-gel process modified by adding several kinds of inorganic salts and surfactants. The addition of any inorganic salt decreased the gel surface area and depressed the formation of mesopores. The surface area and the volume occupied by mesopores changed with the valency of the cation of the salt used. When surfactants were employed as additives, the surface area and the pore size distribution were greatly dependent on the kind of head group of the surfactant: non-ionic surfactant addition monotonously increased the surface area owing to the formation of larger mesopores; anionic surfactant addition significantly decreased the surface area because of the decrease in the volume of mesopores; cationic surfactants caused the surface area to decrease with small additions as anionic surfactants did, while further addition raised the surface area. The rise in the surface area was due to a marked formation of smaller mesopores. These results are discussed on the basis of the interfacial properties of the additives.  相似文献   

19.
用酸催化溶胶-凝胶法制得SiO2溶胶,与丙烯酸酯单体原位聚合,制备了含氟聚丙烯酸酯/SiO2杂化材料。利用红外光谱、场发射扫描电镜、X射线光电子能谱等表征了杂化材料的结构、形态及表面化学组成;研究了SiO2相的形态、分布和界面状况等与杂化材料的表面性能、热学性能和力学性能的关联与影响。结果表明,SiO2在杂化体系中以Si-O网络的形式存在,并与有机相之间有良好键合;杂化材料的疏水性、热稳定性和硬度随着SiO2含量的增加逐渐增强,附着力则先增大后减小。  相似文献   

20.
Structure of diglycerol monomyristate (designated as C14G2) nonionic surfactant reverse micelles in aromatic solvent styrene has been investigated as a function of surfactant concentration, temperature, and water addition by using small-angle X-ray scattering (SAXS) technique. Structure of micelles in real-space so called pair-distance distribution function, p(r), was obtained by the generalized indirect fourier transformation (GIFT) evaluation of SAXS data. It was found that C14G2 spontaneously self-assembles into spheroid reverse micelles with maximum diameter approximately 3.0 nm when added into styrene under ambient condition. The micellar shape and size remained essentially the same despite a wide variation in surfactant concentration (5 to 30%) but an opposite trend was observed with the rise of temperature; size decreased by approximately 25% with increase in temperature from 25 to 75 degrees C. Addition of traces water favored micellar growth and eventually ellipsoid prolate type micelles were formed, whose scenario is understood in terms of decrease in the critical packing parameter (cpp); water hydrates the surfactant's headgroup and decreases cpp. At a particular concentration of water, increasing temperature decreased the micellar size due to dehydration of headgroup. It is interesting to note that size of 1.57% water incorporated micelle is approximately 2.5 times bigger than the empty micelles.  相似文献   

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