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1

TiO2-doped resorcinol–formaldehyde (RF) polymer and carbon gels with photocatalytic activity

100%

Czakkel O., Geissler E., Szilágyi I. M., László K.

Nanomaterials and the Environment

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2013

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vol. 1

23-30

EN

Resorcinol-formaldehyde (RF) polymer gels offer a relatively easy and versatile route for incorporating metals into a carbon aerogel matrix. The hybrid materials thus obtained are ideal candidates for applications involving enhanced adsorption or catalysis. This paper presents a detailed study of Ti-doped RF and carbon aerogels. The metal was introduced into the system at three different stages of the preparation process: during polymerization, by impregnation of the RF gel, or by impregnation of the carbon gel. The structure and morphology of the samples are compared using low temperature N2 adsorption, SEM, and small and wide angle X-Ray scattering (SAXS/WAXS) methods. The TiO2-doped carbon aerogels display photocatalytic activity in breaking down aromatic compounds.

2

Molecularly imprinted microspheres prepared by precipitation polymerization at high monomer concentrations

100%

Renkecz T., László K., Horváth V.

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EN

Highly crosslinked polymer microparticles have been prepared by precipitation polymerization using high monomer loadings (≥25 v/v %) which generally would lead to bulk monoliths. The microparticle format was achieved by the use of non-solvating diluents either alone or in combination with co-solvents. Two distinct morphologies were observed. Monodisperse smooth microspheres were obtained using a thermodynamically good co-solvent whereas segmented irregular particles were formed with poorer co-solvents. It has been found that during polymerization the forming polymer particles were enriched in the co-solvent and this effect was more pronounced when good co-solvents were used. The type of functional monomer, crosslinker and co-solvent, and the non-solvent/co-solvent ratio were identified as influential parameters on the microparticle morphology. With the proposed methodology molecularly imprinted microparticles have been prepared successfully for three different templates, naproxen, diclofenac and toltrazuril using various functional monomers, crosslinkers and polymerization solvent mixtures.

3

Low pressure RF plasma modification of the surface of three different nano-carbon materials

88%

Bertóti I., Mohai M., Balázsi C., László K., Szépvölgyi J.

Open Chemistry

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2015

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vol. 13

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issue 1

EN

Well-ordered nano-carbon materials, like multi-wall carbon nanotubes, graphene oxide, graphene due to their unique physical and chemical properties, are candidates for promising applications. In this work thin multilayered graphene, single layer graphene oxide layers and highly oriented pyrolytic graphite (HOPG) surface were treated by RF activated N2 gas plasma at nominally room temperature. Negative bias in the 0–200 V range and treatment time of 10 min was applied. Surface chemical alterations were followed by X-ray photoelectron spectroscopy (XPS). The applied treatments resulted in a significant build-up of nitrogen in the surface of these nano-carbon materials. The amount of nitrogen varied between 4 and 10 atomic %, depending on type of carbon and on biasing conditions. Evaluating the high-resolution N1s XP spectral region, typically three different chemical bonding states of the nitrogen were delineated. Peak component at 398.3 eV is assigned to C=N–C type, at 399.7 eV to sp2 N in melamine-type ring structure and at 400.9 eV to N substituting carbon in a graphite-like environment. Identical chemical bonding of the nitrogen was detected on the surface of HOPG treated in the same way for comparison.

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1 Molecular Imprinting

1 Nanomaterials and the Environment

1 Open Chemistry

2 2014

1 2013

3 László K.

1 Balázsi C.

1 Bertóti I.

1 Czakkel O.

1 Geissler E.

1 Horváth V.

1 Mohai M.

1 Renkecz T.

1 Szilágyi I. M.

1 Szépvölgyi J.

TiO2-doped resorcinol–formaldehyde (RF) polymer and carbon gels with photocatalytic activity

Molecularly imprinted microspheres prepared by precipitation polymerization at high monomer concentrations

Low pressure RF plasma modification of the surface of three different nano-carbon materials