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991.
Adrián González Jose Ramos Pablo Taboada Jacqueline Forcada 《Journal of polymer science. Part A, Polymer chemistry》2016,54(12):1694-1705
Herein, the synthesis and potential application as cargo delivery systems of thermo‐responsive poly(N‐vinylcaprolactam) (PVCL)‐based, pH‐responsive poly(2‐(diethylamino)ethyl) methacrylate (PDEAEMA)‐based, and thermo‐, and pH‐responsive PDEAEMA/PVCL‐based core–shell nanogels are reported. All the nanogels have been synthesized using different dextran‐methacrylates (Dex‐MAs) as macro‐cross‐linkers. Doxorubicin hydrochloride (DOXO), an anticancer drug, has been effectively loaded into nanogels via hydrogen‐bonding interactions between ? OH groups of DOXO and ? OH groups of Dex‐MA chains. Drug‐release profiles at various pHs, and the cytocompatibility of the DOXO‐loaded nanogels have been assessed in vitro using cervical cancer HeLa and breast cancer MDA‐MB‐231 cell lines. In all the cases, the DOXO release is controlled by Fickian diffusion and case‐II transport, being the diffusional process dominant. In addition, DOXO‐loaded nanogels are efficiently internalized by HeLa and MDA‐MB‐231 cells and DOXO is progressively released in time. Therefore, nanogels synthesized could be suitable and potentially useful as nanocarriers for antitumor drug delivery. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1694–1705 相似文献
992.
Juan Liu Xiaocheng Li Weihong Jia Mingshan Ding Yan Zhang 《Journal of Dispersion Science and Technology》2016,37(9):1294-1302
Rapid separation of emulsified oil from oily wastewater is one of the most serious challenges faced in the petroleum industry. In this study, a rapid and efficient demulsifier, functionalized multiwalled carbon nanotubes (F-MWCNTs), was prepared and used to separate the emulsified oil from oily wastewater. Demulsification test showed that the oil removal efficiency could attain as high as 99.8% at an optimal condition within a few minutes. The micro-morphology of the oil–water mixture before and after demulsification was observed using a polarizing microscope. It was found that the fine oil droplets experienced a rapid coalescence to form oil phase floating on the water surface. Mechanism of the demulsification process was discussed. The introduction of the functional groups (such as ?OH and ?COOH) on the surfaces of F-MWCNTs enable them good amphiphilicity and therefore easily arriving at the oil/water interface to destroy the interfacial protective film mainly composed of asphaltenes and resins. The findings in this work showed that the F-MWCNT is an efficient nanomaterial to remove emulsified oil from the oily wastewater and might have wide application prospects in the petroleum industry. 相似文献
993.
PNVCL‐PEGMA nanohydrogels with tailored transition temperature for controlled delivery of 5‐fluorouracil
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Mirian A. González‐Ayón J. Adriana Sañudo‐Barajas Lorenzo A. Picos‐Corrales Angel Licea‐Claverie 《Journal of polymer science. Part A, Polymer chemistry》2015,53(22):2662-2672
Sensitive nanohydrogels were prepared via surfactant free emulsion copolymerization of N‐vinylcaprolactam and poly(ethylene glycol) methyl ether methacrylate, and either N‐vinylpyrrolidone (VP) or 2‐methacryloyloxybenzoic acid (2MBA) to adjust the transition temperature (Ttr). The crosslinker ethylene glycol dimethacrylate was used for the polymer network construction. The resulting nanohydrogel sizes are between 120 and 300 nm. ρ‐Parameter, obtained from light scattering studies, suggests that core‐sell nanogels of flexible chains were obtained. Ttr increases with increasing comonomer content (VP or 2MBA) and decreases with decreasing pH for 2MBA containing nanohydrogels. Nanohydrogels containing 15.5% of 2MBA exhibit Ttr close to 38 °C. Nanogels are able to control the release of the loaded antineoplastic drug 5‐fluorouracil. For the prepared T/pH‐sensitive nanogels, the release is slower at pH 7.4 and 37 °C than at tumor conditions: pH 6 and 40 °C. Mathematical models were applied to evaluate the kinetics of drug release; Peppas model fitted best indicating a Fickian diffusion trough a sphere. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2662–2672 相似文献
994.
995.
Jacqueline M. Morais Stig E. Friberg 《Journal of Dispersion Science and Technology》2013,34(8):1019-1026
The recently introduced one-step process to form double emulsions is analyzed using generalized phase diagrams of water, ethylene oxide adduct surfactants, and hydrocarbons. With the process used, we found three factors to be involved in the successful formation of double emulsions. Temporary ultra-low interfacial tension allowed drops of irregular shape to exist, a large part of the emulsion formed a bicontinuous microemulsion at intermediate times, and the interfacial tension was temporarily reduced extremely by significant amounts of all three compounds transferred over the interfaces in different directions depending on the stage of the process. 相似文献
996.
Keng‐Jen Lin Chi‐An Dai King‐Fu Lin 《Journal of polymer science. Part A, Polymer chemistry》2009,47(2):459-466
Soap‐free emulsion polymerization of methyl methacrylate (MMA) in the aqueous suspension of montmorillonite (MMT) was able to fabricate the exfoliated MMT/PMMA nanocomposite latex. Because neither MMA nor substantial quantity of potassium persulfide (KPS) initiator could be individually absorbed into the interlayer region of MMT, the polymerizing ionic radicals in water phase were considered as a major component to diffuse into the gallery of MMT. They have been observed to organize into disk‐like micelles in the interlayer regions to exfoliate MMT. The diffusion of the polymerizing ionic radicals was further supported by using sodium dodecyl sulfate (SDS) surfactant as a model compound to diffuse into the gallery of MMT. The exfoliation of MMT was almost completed before micellization stage was over. After exfoliation, the disk‐like micelles became a polymerization loci for monomers. Because the disk‐like micelles in numbers were substantially over the commonly formed spherical micelles in the typical soap‐free emulsion polymerization, the conversion rate of MMA to MMT/PMMA nanocomposite latex was faster. Based on the above experimental observation, a justified exfoliation mechanism of MMT was proposed. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 459–466, 2009 相似文献
997.
M. A. Rodríguez‐Valverde R. Tejera‐García M. A. Cabrerizo‐Vílchez J. Nolla‐Anguera J. Esquena‐Moret 《Journal of Dispersion Science and Technology》2013,34(2):155-163
In this study, effect and correlation of alkyl chain length (C8, C10, C12, C14, and C16) and concentration of n-alkyl sulfate acid used as representative Br?nsted acid-combined-surfactant catalysts on dehydration esterification of oleic acid with 1-octanol as typical substrates are researched. CMC of the series surfactant are measured by surface tension method. The results indicate that alkyl chain length as well as concentration of catalyst plays an important role in determining conversion of esterifications. Appropriate chain length surfactant and concentration should be chosen for the combined-surfactant catalyzed reaction. 相似文献
998.
Zengjiang WeiChaoyang Wang Shengwen ZouHao Liu Zhen Tong 《Colloids and surfaces. A, Physicochemical and engineering aspects》2011,392(1):116-123
Magnetic iron oxide (Fe2O3, maghemite) nanoparticle-coated micrometer-sized poly(lactic-co-glycolic acid) (PLGA) microcapsules were fabricated via a combined system of “Pickering-type” emulsion route and solvent volatilization method in the absence of any molecular surfactants. Stable oil-in-water emulsions were prepared using Fe2O3 nanoparticles as a particulate emulsifier and a dichloromethane (CH2Cl2) solution of PLGA as an oil phase. The Fe2O3 nanoparticle-coated PLGA microcapsules were fabricated by the evaporation of CH2Cl2 from the emulsion, and then bare-PLGA microcapsules were prepared by the removal of the Fe2O3 nanoparticles using HCl aqueous solution. The two types of microcapsules were characterized in terms of size, component and morphology using scanning electronic microscope (SEM), Fourier-transform infrared, optical microscope, and so on. SEM with energy dispersive analysis system (EDS) study confirmed that, there is negligibly small amount of Fe2O3 in the bare-PLGA microcapsules after washing with HCl aqueous solution. Moreover, a possible mechanism for the formation of the microcapsules was proposed. The combined system of Pickering emulsion and solvent volatilization opens up a new route to fabricate a variety of microcapsules. 相似文献
999.
氟改性聚氨酯乳液的合成及其表面性能 总被引:2,自引:0,他引:2
氟改性聚氨酯乳液的合成及其表面性能;氟改性;聚氨酯乳液;表面性能 相似文献
1000.