MedWorm.com provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest items from the 'Colloid and Polymer Science' source. Fri, 28 Oct 2011 00:35:11 +0100 http://www.medworm.com/index.php?rid=5215942&cid=s_38016_70_f&fid=38016&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21892247%26dopt%3DAbstract The objective of this work was to delineate the effect of hydrophilic and hydrophobic polymeric additives on sol-gel transition and release profile of timolol maleate (TM) from poly (ethylene glycol)-poly (ε-caprolactone)- poly (ethylene glycol) (PEG-PCL-PEG)-based thermosensitive hydrogel. Polycaprolactone (hydrophobic additive) and polyvinyl alcohol (PVA) (hydrophilic additive) reduced critical gel concentration of PEG-PCL-PEG triblock polymer. The effect of PCL on sol-gel transition was more pronounced than PVA. However, with PCL no statistically significant difference in release profile was observed. The effect of PVA on release profile was more pronounced, which reduced the cumulative percentage release of TM from 86.4±0.8% to 73.7±1.8% over 316 h. Moreover, cytotoxicity of the hyd... Colloid and Polymer Science journals http://www.medworm.com/rss/comments.php?id=5215942 Thu, 01 Sep 2011 04:00:00 +0100 5215942 http://www.medworm.com/index.php?rid=5215943&cid=s_38016_70_f&fid=38016&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21892246%26dopt%3DAbstract Authors: Gosecka M, Griffete N, Mangeney C, Chehimi MM, Slomkowski S, Basinska T Abstract Optical properties of polymer microspheres with polystyrene cores and polyglycidol-enriched shells poly(styrene/α-tert-butoxy-ω-vinylbenzyl-polyglycidol) (P(S/PGL) particles with number average diameters D(n) determined by scanning electron microscopy equal 237 and 271 nm), were studied before and after immobilization of ovalbumin. The particles were synthesized by emulsifier-free emulsion copolymerization of styrene and polyglycidol macromonomer (poly(styrene/α-tert-butoxy-ω-vinylbenzyl-polyglycidol)) initiated with potassium persulfate. Molar fraction of polyglycidol units in the interfacial layer of the microspheres determined by XPS was equal 42.6 and 34.0%, for the particles with D(n... Colloid and Polymer Science journals http://www.medworm.com/rss/comments.php?id=5215943 Mon, 01 Aug 2011 04:00:00 +0100 5215943 http://www.medworm.com/index.php?rid=5041613&cid=s_38016_70_f&fid=38016&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21765579%26dopt%3DAbstract Authors: Brzozowska AM, Keesman KJ, de Keizer A, Leermakers FA We discuss the structure and formation of Ionomer Complexes formed upon mixing a grafted block copolymer (poly(acrylic acid)-b-poly(acrylate methoxy poly(ethylene oxide)), PAA(21)-b-PAPEO(14)) with a linear polyelectrolyte (poly(N-methyl 2-vinyl pyridinium iodide), P2MVPI), called grafted block ionomer complexes (GBICs), and a chemically identical grafted copolymer (poly(acrylic acid)-co-poly(acrylate methoxy poly(ethylene oxide)), PAA(28)-co-PAPEO(22)) with a linear polyelectrolyte, called grafted ionomer complexes (GICs). Light scattering measurements show that GBICs are much bigger (~70-100 nm) and GICs are much smaller or comparable in size (6-22 nm) to regular complex coacervate core micelles (C3Ms). The mechanism of... Colloid and Polymer Science journals http://www.medworm.com/rss/comments.php?id=5041613 Tue, 31 May 2011 23:00:00 +0100 5041613 http://www.medworm.com/index.php?rid=5041612&cid=s_38016_70_f&fid=38016&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21765580%26dopt%3DAbstract Authors: Memesa M, Lenz S, Emmerling SG, Nett S, Perlich J, Müller-Buschbaum P, Gutmann JS Titania nanoparticles are prepared by sol-gel chemistry with a poly(ethylene oxide) methyl ether methacrylate-block-poly(dimethylsiloxane)-block-poly(ethylene oxide) methyl ether methacrylate triblock copolymer acting as the templating agent. The sol-gel components-hydrochloric acid, titanium tetraisopropoxide, and triblock copolymer-are varied to investigate their effect on the resulting titania morphology. An increased titania precursor or polymer content yields smaller primary titania structures. Microbeam grazing incidence small-angle X-ray scattering measurements, which are analyzed with a unified fit model, reveal information about the titania structure sizes. These small structures could ... Colloid and Polymer Science journals http://www.medworm.com/rss/comments.php?id=5041612 Tue, 31 May 2011 23:00:00 +0100 5041612 http://www.medworm.com/index.php?rid=5041611&cid=s_38016_70_f&fid=38016&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21765581%26dopt%3DAbstract Authors: Phan HT, Zhu K, Kjøniksen AL, Nyström B Temperature-induced interchain association and contraction of species in aqueous solutions of charged (MHEC(-)-g-PNIPAAM) and uncharged (MHEC-g-PNIPAAM) modified hydroxyethylcellulose-graft-poly(N-isopropylacrylamide) copolymer have been studied with the aid of turbidimetry and dynamic light scattering (DLS). It was shown that by attaching PNIPAAM chains to the backbone of a hydrophilic cellulose derivative, a strongly temperature-responsive copolymer could be prepared. The results show an intriguing interplay between interchain association and contraction of the multichain species. The transition zone for compression is narrow, and the compaction effect is promoted by a low polymer concentration and charges on the polymer moieties. Th... Colloid and Polymer Science journals http://www.medworm.com/rss/comments.php?id=5041611 Tue, 31 May 2011 23:00:00 +0100 5041611 http://www.medworm.com/index.php?rid=4745608&cid=s_38016_70_f&fid=38016&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21461041%26dopt%3DAbstract Authors: Chen TY, Chen JK In this paper, we describe a graft polymerization/solvent immersion method for generating poly(2-hydroxyethyl methacrylate) (PHEMA) brushes in various patterns. We used a novel fabrication process, involving very-large-scale integration and oxygen plasma treatment, to generate well-defined patterns of polymerized PHEMA on patterned Si(100) surfaces. We observed brush- and mushroom-like regions for the PHEMA brushes, with various pattern resolutions, after immersing wafers presenting lines of these polymers in MeOH and n-hexane, respectively. The interaction between PHEMA and ferritin protein sheaths in MeOH and n-hexane (good and poor solvent for PHEMA, respectively) was used to capture and release ferritins from fluidic system. The "tentacles" behaver for PHE... Colloid and Polymer Science journals http://www.medworm.com/rss/comments.php?id=4745608 Tue, 01 Feb 2011 00:00:00 +0100 4745608 http://www.medworm.com/index.php?rid=4745607&cid=s_38016_70_f&fid=38016&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21472022%26dopt%3DAbstract Authors: Wiśniewska M The influence of polyvinyl alcohol (PVA) adsorption on the structure of the diffuse layer of silica (SiO(2)) in the temperature range 15-35 °C was examined. The microelectrophoresis method was used in the experiments to determine the zeta potential of the solid particles in the absence and presence of the polymer. The adsorption of PVA macromolecules causes the zeta potential decrease in all investigated SiO(2) systems. Moreover this, decrease is the most pronounced at the highest examined temperature. Obtained results indicate that the conformational changes of adsorbed polymer chains are responsible for changes in electrokinetic properties of silica particles. Moreover, the structure of diffuse layer on the solid surface with adsorbed polymer results from the... Colloid and Polymer Science journals http://www.medworm.com/rss/comments.php?id=4745607 Tue, 01 Feb 2011 00:00:00 +0100 4745607 http://www.medworm.com/index.php?rid=4636860&cid=s_38016_70_f&fid=38016&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21423784%26dopt%3DAbstract Authors: Hu X, Tong Z, Lyon LA Surfactant-free, radical precipitation co-polymerization of N-isopropylmethacrylamide (NIPMAm) and the cationic co-monomer N-(3-aminopropyl) methacrylamide hydrochloride (APMH) was carried out to prepare microgels functionalized with primary amines. The morphology and hydrodynamic diameter of the microgels were characterized by atomic force microscopy (AFM) and photon correlation spectroscopy (PCS), with the effect of NaCl concentration and initiator type on the microgel size and yield being investigated. When a V50-initiated reaction was carried out in pure water, relatively small microgels (~160 nm diameter) were obtained in low yield (~20%). However, both the yield and size increased if the reaction was carried out in saline or by using APS as initiato... Colloid and Polymer Science journals http://www.medworm.com/rss/comments.php?id=4636860 Sat, 04 Dec 2010 00:00:00 +0100 4636860 http://www.medworm.com/index.php?rid=4318709&cid=s_38016_70_f&fid=38016&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21170115%26dopt%3DAbstract This study also shows that molecular diffusion NMR combined with spin diffusion NMR is useful in studying the drug loading and diffusion properties in hydrogels for the purpose of drug delivery applications. PMID: 21170115 [PubMed - as supplied by publisher] (Source: Colloid and Polymer Science) Colloid and Polymer Science journals http://www.medworm.com/rss/comments.php?id=4318709 Wed, 01 Dec 2010 00:00:00 +0100 4318709 http://www.medworm.com/index.php?rid=4247992&cid=s_38016_70_f&fid=38016&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D21125002%26dopt%3DAbstract Authors: Brzozowska AM, de Keizer A, Detrembleur C, Cohen Stuart MA, Norde W We have studied the formation and the stability of ionomer complexes from grafted copolymers (GICs) in solution and the influence of GIC coatings on the adsorption of the proteins β-lactoglobulin (β-lac), bovine serum albumin (BSA), and lysozyme (Lsz) on silica and polysulfone. The GICs consist of the grafted copolymer PAA(28)-co-PAPEO(22) {poly(acrylic acid)-co-poly[acrylate methoxy poly(ethylene oxide)]} with negatively charged AA and neutral APEO groups, and the positively charged homopolymers: P2MVPI(43) [poly(N-methyl 2-vinyl pyridinium iodide)] and PAH∙HCl(160) [poly(allylamine hydrochloride)]. In solution, these aggregates are characterized by means of dynamic and static light scattering. They appea... Colloid and Polymer Science journals http://www.medworm.com/rss/comments.php?id=4247992 Mon, 01 Nov 2010 00:00:00 +0100 4247992 http://www.medworm.com/index.php?rid=4061228&cid=s_38016_70_f&fid=38016&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20927181%26dopt%3DAbstract Authors: Król B, Król P, Pikus S, Chmielarz P, Skrzypiec K Polyurethane cationomers were synthesised in the reaction of 4,4'-methylenebis(phenyl isocyanate) with polyoxyethylene glycol (M = 2,000) or poly(tetrafluoroethyleneoxide-co-difluoromethylene oxide) α,ω-diisocyanate and N-methyl diethanolamine. Amine segments were built-in to the urethane-isocyanate prepolymer in the reaction with 1-bromobutane or formic acid, and then they were converted to alkylammonium cations. The obtained isocyanate prepolymers were then extended in the aqueous medium that yielded stable aqueous dispersions which were applied on the surfaces of test poly(tetrafluoroethylene) plates. After evaporation of water, the dispersions formed thin polymer coatings. (1)H, (13)C NMR and IR spectral methods were... Colloid and Polymer Science journals http://www.medworm.com/rss/comments.php?id=4061228 Sat, 31 Jul 2010 23:00:00 +0100 4061228 http://www.medworm.com/index.php?rid=3809357&cid=s_38016_70_f&fid=38016&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20671774%26dopt%3DAbstract Authors: Brzozowska AM, de Keizer A, Norde W, Detrembleur C, Cohen Stuart MA We have studied the formation and the stability of grafted block complex coacervate core micelles (C3Ms) in solution and the influence of grafted block C3M coatings on the adsorption of the proteins beta-lactoglobulin, bovine serum albumin, and lysozyme. The C3Ms consist of a grafted block copolymer PAA(21)-b-PAPEO(14) (poly(acrylic acid)-b-poly(acrylate methoxy poly(ethylene oxide)), with a negatively charged PAA block and a neutral PAPEO block and a positively charged homopolymer P2MVPI (poly(N-methyl 2-vinyl pyridinium iodide). In solution, these C3Ms partly disintegrate at salt concentrations between 50 and 100 mM NaCl. Adsorption of C3Ms and proteins has been studied with fixed-angle optical reflectometry... Colloid and Polymer Science journals http://www.medworm.com/rss/comments.php?id=3809357 Wed, 30 Jun 2010 23:00:00 +0100 3809357 http://www.medworm.com/index.php?rid=3212912&cid=s_38016_70_f&fid=38016&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20098514%26dopt%3DAbstract Authors: Essawy H, Tauer K Poly(terephthalamide) microcapsules can be reproducibly and easily prepared by interfacial polycondensation around emulsion droplets in water. Oil drops of cyclohexane/chloroform mixture stabilized with poly(vinyl alcohol) containing terephthaloylchloride serve as soft template. The interfacial polycondensation starts immediately after addition of an amine mixture (hexamethylenediamine/diethylenetriamine). Light and scanning electron microscopy prove the formation of capsules with size distribution in the range from a few up to 100 microm depending on particular composition of the reaction mixture. The morphology of the capsule wall is characterized by precipitated particles. If instead of pure organic solvents a reactive oil phase is used as template, the ca... Colloid and Polymer Science journals http://www.medworm.com/rss/comments.php?id=3212912 Wed, 27 Jan 2010 20:10:08 +0100 3212912 http://www.medworm.com/index.php?rid=3212911&cid=s_38016_70_f&fid=38016&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20098719%26dopt%3DAbstract This article deals with topics where I expect special future challenges, exemplifying these by experiments out of my own department. One area where I expect large progress also in view of many technical developments in the past concerns the understanding of the structure of fluid interfaces at the atomic level. It is shown by non-linear optical spectroscopies that the free water surface is ice-like and can be "liquefied" by ion adsorption. X-ray fluorescence from the interface demonstrates that ion binding is very specific which cannot be explained by existing theories. A second major area are nonequilibrium features, and one of the old and new ones here is nucleation and growth. This presentation concentrates on effects produced by ultrasound, a well-defined trigger of gas bubble formatio... Colloid and Polymer Science journals http://www.medworm.com/rss/comments.php?id=3212911 Fri, 01 Jan 2010 00:00:00 +0100 3212911 http://www.medworm.com/index.php?rid=2924057&cid=s_38016_70_f&fid=38016&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19851469%26dopt%3DAbstract Authors: Ziegler A, Landfester K, Musyanovych A Phosphonate-functionalized polymer nanoparticles were synthesized by free-radical copolymerization of vinylphosphonic acid (VPA) with styrene or methyl methacrylate (MMA) using the miniemulsion technique. The influence of different parameters such as monomer and surfactant type, amount of vinylphosphonic acid on the average particle size, and size distribution was studied using dynamic light scattering and transmission electron microscopy. Depending on the amount and type of the surfactant used (ionic or non-ionic), phosphonate-functionalized particles in a size range from 102 to 312 nm can be obtained. The density of the phosphonate groups on the particle surface was higher in the case of using MMA as a basis monomer than polystyrene. Th... Colloid and Polymer Science journals http://www.medworm.com/rss/comments.php?id=2924057 Sun, 25 Oct 2009 06:54:05 +0100 2924057 http://www.medworm.com/index.php?rid=2877252&cid=s_38016_70_f&fid=38016&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19816528%26dopt%3DAbstract Authors: Iyota H, Krastev R The adsorption, micelle formation, and salting out of sodium dodecyl sulfate in the presence of sodium chloride were studied from the viewpoint of their mixed adsorption and aggregate formation. The surface tension of aqueous solutions of a sodium chloride-sodium dodecyl sulfate mixture was measured as a function of the total molality and composition of the mixture. Phase diagrams of adsorption and aggregate formation were obtained by applying thermodynamic equations to the surface tension. Judging from the phase diagrams, sodium chloride and sodium dodecyl sulfate are miscible in the adsorbed film at very large composition of sodium chloride and in the salted-out crystalline particle, while they are immiscible in the micelle. The miscibilities in the adsorb... Colloid and Polymer Science journals http://www.medworm.com/rss/comments.php?id=2877252 Tue, 31 Mar 2009 23:00:00 +0100 2877252 http://www.medworm.com/index.php?rid=2877251&cid=s_38016_70_f&fid=38016&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19816529%26dopt%3DAbstract Authors: Texter J Templating processes for creating polymerized hydrogels are reviewed. The use of contact photonic crystals and of non-contact colloidal crystalline arrays as templates are described and applications to chemical sensing and device fabrication are illustrated. Emulsion templating is illustrated in the formation of microporous membranes, and templating on reverse emulsions and double emulsions is described. Templating in solutions of macromolecules and micelles is discussed and then various applications of hydrogel templating on surfactant liquid crystalline mesophases are illustrated, including a nanoscale analogue of colloidal crystalline array templating, except that the bead array in this case is a cubic array of nonionic micelles. The use of particles as templates i... Colloid and Polymer Science journals http://www.medworm.com/rss/comments.php?id=2877251 Sun, 01 Mar 2009 00:00:00 +0100 2877251 http://www.medworm.com/index.php?rid=2877250&cid=s_38016_70_f&fid=38016&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19816531%26dopt%3DAbstract We present a systematic study of flexible cylindrical brush-shaped macromolecules in a good solvent by small-angle neutron scattering (SANS), static light scattering (SLS), and by dynamic light scattering (DLS) in dilute and semi-dilute solution. The SLS and SANS data extrapolated to infinite dilution lead to the shape of the polymer that can be modeled in terms of a worm-like chain with a contour length of 380 nm and a persistence length of 17.5 nm. SANS data taken at higher polymer concentration were evaluated by using the polymer reference interaction site model (PRISM). We find that the persistence length reduce from 17.5 nm at infinite dilution to 5.3 nm at the highest concentration (volume fraction 0.038). This is comparable with the decrease of the persistence length in semi-dilute ... Colloid and Polymer Science journals http://www.medworm.com/rss/comments.php?id=2877250 Sun, 01 Feb 2009 00:00:00 +0100 2877250 http://www.medworm.com/index.php?rid=1799586&cid=s_38016_70_f&fid=38016&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D18769603%26dopt%3DAbstract Authors: Blackburn WH, Lyon LA Small, monodispersed nanogels (~ 50-nm radius) were synthesized by free-radical precipitation polymerization and characterized using a suite of light scattering and chromatography methods. Nanogels were synthesized with either N-isopropylacrylamide or N-isopropylmethacrylamide as the main monomer, with acrylic acid or 4-acrylamidofluorescein as a co-monomer and N, N'-methylenebis(acrylamide) as a cross-linker. By varying the surfactant and initiator concentrations, particle size was controlled while maintaining excellent monodispersity. An amine-containing shell was added to these core particles to facilitate subsequent bioconjugation. Successful conjugation of folic acid to the particles was demonstrated as an example of how such materials might be emplo... Colloid and Polymer Science journals http://www.medworm.com/rss/comments.php?id=1799586 Wed, 17 Sep 2008 18:01:42 +0100 1799586