Plasma Processing Approach to Molecular Surface Tailoring of Nanoparticles: Improved Photocatalytic Activity of TiO<sub>2</sub>.

Cho, Jai; Dénès, F.; Timmons, Richard B.

doi:10.1002/chin.200637016

Cited by 3 publications

(6 citation statements)

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“…A home-built custom reactor, capable of continuous 3608 rotation during the plasma deposition, was employed to overcome the tendency for particle aggregation and thus promote more uniform polymer film coverage of the substrates. 37,38 One gram samples of the particles were coated in each run. The polypropylene microspheres were soaked in ethanol, followed by prolonged vacuum drying prior to the plasma treatment.…”

Section: Modification Of Polymeric Surfacesmentioning

confidence: 99%

“…Our laboratory has recently developed a modified Radio Frequency Glow Discharge (RFGD) technique to functionalize a wide variety of micro, 37 and more recently, nanosized, spheres. 38 Additionally, using a pulsed plasma technique, we have previously shown that we can effectively control the film chemistry obtained from a given monomer undergoing polymerization via simple variations in the plasma duty cycles employed. This film chemistry control can be used to permit retention of normally reactive functional groups in monomers polymerized under plasma conditions 39,40 and this technology has been successfully employed in a variety of biomaterial applications.…”

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confidence: 99%

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Surface chemistry influences implant‐mediated host tissue responses

Kamath

Bhattacharyya

Padukudru

et al. 2007

J Biomedical Materials Res

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108

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Implant-mediated fibrotic reactions are detrimental to the performance of encapsulated cells, implanted drug release devices and sensors. To improve the implant function and longevity, research has emphasized altering cellular responses. Although material surface functional groups have been shown to be potent in affecting cellular activity in vitro and short term in vivo responses, these groups appear to have little influence on long-term in vivo fibrotic reactions, possibly as a result of insufficient interactions between recruited host cells and functional groups on the implants. To maximize the influence of functionality on cells, and to mimic drug release microspheres, functionalized micron-sized particles were created and tested for their ability in modulating tissue responses to biomaterial implants. In this work, the surfaces of polypropylene particles were controllably coated with four different functional groups, specifically –OH, -NH2, -CFx and –COOH, using a radio frequency glow discharge plasma polymerization technique. The effect of these surface functionalities on host tissue responses were then evaluated using a mice subcutaneous implantation model. Major differences were observed in contrasting tissue response to the different chemistries. Surfaces with –OH and –NH2 surface groups induced the thickest fibrous capsule accompanied with the greatest cellular infiltration into the implants. In contrast, surfaces with –CFx and –COOH exhibited the least inflammatory/fibrotic responses and cellular infiltrations. The present results clearly demonstrate that, by increasing the available functionalized surface area and spatial distribution, the effect of surface chemistry on tissue reactivity can be substantially enhanced.

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Section: Modification Of Polymeric Surfacesmentioning

confidence: 99%

mentioning

confidence: 99%

Surface chemistry influences implant‐mediated host tissue responses

Kamath

Bhattacharyya

Padukudru

et al. 2007

J Biomedical Materials Res

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108

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“…Furthermore, the plasma deposit forms a pinhole-free, conformal film over the substrate. Plasma polymerisation has been successfully applied to substrates such as 3D scaffolds [22] and microparticles [23]. Gradients of chemical functionality have also been fabricated using this method [24] and can be tailored for investigations into cell behaviour [16,25].…”

Section: Introductionmentioning

confidence: 99%

Gradient Technology for High‐Throughput Screening of Interactions between Cells and Nanostructured Materials

Michelmore

Clements

Steele

et al. 2012

Journal of Nanomaterials

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We present a novel substrate suitable for the high-throughput analysis of cell response to variations in surface chemistry and nanotopography. Electrochemical etching was used to produce silicon wafers with nanopores between 10 and 100 nm in diameter. Over this substrate and flat silicon wafers, a gradient film ranging from hydrocarbon to carboxylic acid plasma polymer was deposited, with the concentration of surface carboxylic acid groups varying between 0.7 and 3% as measured by XPS. MG63 osteoblast-like cells were then cultured on these substrates and showed greatest cell spreading and adhesion onto porous silicon with a carboxylic acid group concentration between 2-3%. This method has great potential for high-throughput screening of cell-material interaction with particular relevance to tissue engineering.

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“…These prior investigations have included doping TiO 2 with transition metals such as Ni, Fe, Cu or Mn to broaden light absorption into the visible region and decrease the rate of recombination between exited electrons and holes. TiO 2 has also been doped by a variety of other materials including carbon, nitrogen, − sulfur, fluorine, − and tetramethyltin …”

Section: Introductionmentioning

confidence: 99%

“…The use of plasma processing to modify TiO 2 catalytic activity has been reported in several recent studies. These studies include use of a nitrogen discharge to produce N-doped TiO 2 , acrylic acid to deposit an amorphous polymer coating on TiO 2 , and plasma deposition of a tin containing coating on TiO 2 which was subsequently converted to tin oxide by calcination . In all three cases appreciable increases in TiO 2 photocatalytic activity were reported.…”

Section: Introductionmentioning

confidence: 99%

Plasma Surface Modified TiO₂ Nanoparticles: Improved Photocatalytic Oxidation of Gaseous m-Xylene

Sumitsawan

Cho

Sattler

et al. 2011

Environ. Sci. Technol.

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Titanium dioxide (TiO(2)) is a preferred catalyst for photocatalytic oxidation of many air pollutants. In an effort to enhance its photocatalytic activity, TiO(2) was modified by pulsed plasma treatment. In this work, TiO(2) nanoparticles, coated on a glass plate, were treated with a plasma discharge of hexafluoropropylene oxide (HFPO) gas. By appropriate adjustment of discharge conditions, it was discovered that the TiO(2) particles can be either directly fluorinated (Ti-F) or coated with thin perfluorocarbon films (C-F). Specifically, under relatively high power input, the plasma deposition process favored direct surface fluorination. The extent of Ti-F formation increased with increasing power input. In contrast, at lower average power inputs, perfluorocarbon films are deposited on the surface of the TiO(2) particles. The plasma surface modified TiO(2) nanoparticles were subsequently employed as catalysts in the photocatalytic oxidation of m-xylene in air, as carried out inside a batch reactor with closed loop constant gas circulation. Both types of modified TiO(2) were significantly more catalytically active than that of the unmodified particles. For example, the rate constant of m-xylene degradation was increased from 0.012 min(-1) with untreated TiO(2) to 0.074 min(-1) with fluorinated TiO(2). Although it is not possible to provide unequivocal reasons for this increased photocatalytic activity, it is noted that the plasma surface treatment converted the TiO(2) from hydrophilic to highly hydrophobic, which would provide more facile catalyst adsorption of the xylene from the flowing air. Also, based on literature reports, the use of fluorinated TiO(2) reduces electron-hole recombination rates, thus increasing the photocatalytic activity.

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Plasma Processing Approach to Molecular Surface Tailoring of Nanoparticles: Improved Photocatalytic Activity of TiO₂.

Abstract: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Cited by 3 publications

References 1 publication

Surface chemistry influences implant‐mediated host tissue responses

Surface chemistry influences implant‐mediated host tissue responses

Gradient Technology for High‐Throughput Screening of Interactions between Cells and Nanostructured Materials

Plasma Surface Modified TiO₂ Nanoparticles: Improved Photocatalytic Oxidation of Gaseous m-Xylene

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Plasma Processing Approach to Molecular Surface Tailoring of Nanoparticles: Improved Photocatalytic Activity of TiO2.

Abstract: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Cited by 3 publications

References 1 publication

Surface chemistry influences implant‐mediated host tissue responses

Surface chemistry influences implant‐mediated host tissue responses

Gradient Technology for High‐Throughput Screening of Interactions between Cells and Nanostructured Materials

Plasma Surface Modified TiO2 Nanoparticles: Improved Photocatalytic Oxidation of Gaseous m-Xylene

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Product

Resources

About

Plasma Processing Approach to Molecular Surface Tailoring of Nanoparticles: Improved Photocatalytic Activity of TiO₂.

Plasma Surface Modified TiO₂ Nanoparticles: Improved Photocatalytic Oxidation of Gaseous m-Xylene