Surface modification

About: Surface modification is a research topic. Over the lifetime, 35544 publications have been published within this topic receiving 859567 citations.

Adsorption on new and modified inorganic sorbents

Abstract: Part 1 Preparation, structure and properties of new and modified inorganic sorbents: computational studies on the design of synthetic sorbents for selective adsorption of molecules, R. Vetrivel et al controlled porosity glasses (CPGs) as adsorbents, molecular sieves, ion-exchanges and support materials, A.L. Dawidowicz influence of pH of precipitation of hydroxides on the structure of co-precipitated adsorbents, V.S. Komarov colloidal silicas, S. Kondo complex carbon-mineral adsorbents - preparation, surface properties and their modification, R. Leboda and A. Dabrowski solid-phase hydrosilylation reactions with participation of modified silica surface, V.A. Tertykh and L.A. Belyakova structure and molecular organization of bonded layers of chemically modified silicas, A. Yu et al the chemical basis of surface modification technology of silica and alumina by molecular layering method, A.A. Malygin et al kinetics of organic compounds chemisorption from the gas phase on oxides surface, V.I. Bogillo functionalized polysiloxane sorbents - preparation, structure, properties and use, Yu L. Zub and R.V. Parish surface structure and molecular adsorption of apatites, T. Ishikawa surface chemistry and adsorption properties of Al13 colloids, J.Y. Bottero and J.M. Cases. Part 2 Adsorption from gaseous phase: Computer simulation of adsorption on amorphous oxide surface, V. Bakaev and W. Steele on the nature of the energetic heterogeneity of water/oxide interface in adsorption phenomena occurring at oxide surface, W. Rudzinski et al energetic heterogeneity of porous inorganic oxides - adsorption and chromatographic studies, M. Jaroniec adsorption kinetics on real surfaces, G.F. Cerofolini inverse gas chromatography in the examination of acid-base and some other properties of solid materials, A. Voekel chemical and morphological characteristics of inorganic sorbents with respect to gas adsorption, E. Papirer and H. Balard structure and properties of the films formed by organic substances on silica gel surface, investigations by inverse gas chromatography (IGC), J. Rayss the use of gas chromatography to study the adsorption from gaseous phase at the finite dilution, F.J. Lopez Garzon and M. Domingo Garcia molecular statistic and gas chromatographic study of hydrocarbons adsorption on the modified layer silicates and silica in the Henry region, Yu I. Tarasevich et al micropore filling mechanism in inorganic sorbents, K. Kaneko phase transitions in adsorbed layers, A. Patrykiejew drying of gases and liquids by activated alumina, S. Sircar et al. Part 3 Adsorption from solution: characterization of inorganic sorbents by means of adsorption at the liquid-solid interface, A. Dabrowski et al study of adsorption from solutions by chromatography, V. Ya Davydov equilibria of adsorption from solutions on the silica surface, V.A. Tertykh and V.V. Yanishpolskii adsorption from dilute solutions - some novel aspects, P. Nikitas (Part contents)

Higher Dispersion Efficacy of Functionalized Carbon Nanotubes in Chemical and Biological Environments

Abstract: Aqueous dispersions of functionalized carbon nanotubes (CNTs) are now widely used for biomedical applications. Their stability in different in vitro or in vivo environments, however, depends on a wide range of parameters, such as pH and salt concentrations of the surrounding medium, and length, aspect ratio, surface charge, and functionalization of the applied CNTs. Although many of these aspects have been investigated separately, no study is available in the literature to date, which examines these parameters simultaneously. Therefore, we have chosen five types of carbon nanotubes, varying in their dimensions and surface properties, for a multidimensional analysis of dispersion stability in salt solutions of differing pH and concentrations. Furthermore, we examine the dispersion stability of oxidized CNTs in biological fluids, such as cellular growth media and human plasma, and their toxicity toward cancer cells. To enhance dispersibility and biocompatibility, the influence of different functionalization schemes is studied. The results of our investigations indicate that both CNT dimensions and surface functionalization have a significant influence on their dispersion and in vitro behavior. In particular, factors such as a short aspect ratio, presence of oxidation debris and serum proteins, low salt concentration, and an appropriate pH are shown to improve the dispersion stability. Furthermore, covalent surface functionalization with amine-terminated polyethylene glycol (PEG) is demonstrated to stabilize CNT dispersions in various media and to reduce deleterious effects on cultured cells. These findings provide crucial data for the development of biofunctionalization protocols, for example, for future cancer theranostics, and optimizing the stability of functionalized CNTs in varied biological environments.

Surface Modification of Colloidal Gold by Chemisorption of Alkanethiols in the Presence of a Nonionic Surfactant

Abstract: Surface modification of colloidal gold with 11-mercaptoundecanoic acid or 16-mercaptohexadecanoic acid was performed in the absence or in the presence of the nonionic surfactant polyoxyethylene (20) sorbitan monolaurate (Tween 20). The stability of the colloidal systems was assessed with optical absorption spectroscopy. The surface-modified nanoparticles were stable only within a narrow range of intermediate pH values when chemisorption of alkanethiols was performed in the absence of Tween 20. This was explained in terms of partial ionization of the surface carboxylic groups and charge neutralization at high pH values by counterions present in the buffer solutions. Formation of a physisorbed monolayer of Tween 20 onto the nanoparticles prior to chemisorption of alkanethiols resulted in surface-modified colloidal gold that was stable over a broader range of pH values. Parallel experiments demonstrated that self-assembled monolayers could form on flat substrates in the presence of Tween 20. Therefore, possi...