In order to correlate the biological activity of silica to its surface properties, the analysis of surface sites on three kinds of silicas of different origins and textures has been performed by adsorption calorimetry.
Authors:D. Berkün, D. Balköse, F. Tıhmınlıoǧlu, and S. Altınkaya
Two types of films consisting of sodium salt of carboxymethyl cellulose (NaCMC) and hydroxypropyl cellulose (HPC) as film
forming materials and glycerin as plasticizer were prepared, characterized and their water vapour sorption properties were
The water sorption isotherms of the films were measured using a magnetic suspension balance. Results show that diffusion of
water vapour in NaCMC based film is faster than that in HPC based films, due to the heterogeneous structure and larger pore
dimensions of the NaCMC films.
Thermal analysis of the 10 m surface of materials using TA Instruments' -TA thermal probe and pulsed force mode AFM has
shown promising results. This addresses the need of additional surface characterization based on principle of Thermal Analysis,
which is complementary to other surface characterization techniques, i.e., Surface-IR, TOF-SIMS, etc. The method calls for
identification of surface landscape by imaging first, followed by fast heating the spots of interest. The micro thermal probe
is viewed to heat a small material with a tiny heater rather than to heat small material with a large heater in conventional
thermal analysis. In this paper, we demonstrate the applicability in the adhesion temperature of the topical coatings of Tyvek
HDPE sheets, fusion of the heat-processed polyethylene fibers in a bundle, the surface crystallinity of PET pellets, and two
examples of phase images of toughened Nylon 66. Comparisons were made where it is possible with standard thermal analysis
techniques as well as with the microscopic techniques of AFM, TEM and optical.
Authors:H. Ortiz-Oliveros, E. Ordoñez-Regil, and S. Fernández-Valverde
The sorption of uranium(VI) on the perovskite structure of strontium titanate in a 0.5M KNO3 solution is studied. SrTiO3 commercial material was characterized by XRD showing a tausonite face, with a specific area of 2.42 m2.g−1. The electrical surface characterization of the compound was performed by mass and potentiometric titrations. pHpzc in water was 8.5±0.3 and 9.1±0.2 in 0.5M KNO3 solution, showing a positively charged surface. FITEQL 4.0 program was used to calculate the sorption curves and the surface
acidity constants by the constant capacitance model obtaining: log K1 = 8.67 and log K2 = −9.43. The sorption edge was fitted with two different uranium(VI) species sorbed, corresponding to bidentate complexes
of UO22+ and UO2(OH)2H2O on the surface of strontium titanate.
Authors:N. Nava, J. Jacobs, A. García, J. Rosink, M. Valenzuela, L. Van Ijzendoorn, and H. Brongersma
ZnxMg1-xFe2O4 mixed oxide spinels (x=0.0, 0.2, 0.4, 0.6, 0.8, and 1.0) were prepared by conventional solid state reaction method. Bulk and surface characterization of these ferrites were carried out by different techniques. The ratios Zn/Fe and Mg/Fe determined by PIXE and AAS were nearly as expected from the synthesis mixture, i.e. following the substitution model. XRD shows only a spinel structure (fcc) with increasing lattice parameter as x increases from 0 to 1. The bulk ratios of tetrahedral to octahedral sites occupied by Fe cations measured by NGR are in good agreement with the theoretical bulk stoichiometry. LEIS results indicate a Mg substitution by Fe cations at the surface. Only octahedral sites are proposed at the surface. The transition from inverse to normal spinel was follow through NGR-spectra occurring at x=0.4.
Authors:Hadi Fallah Moafi, Abdollah Fallah Shojaie, and Mohammad Ali Zanjanchi
, M , Mielczarski , E , Thampi , K , Buffat , P , Bensimon , M , Kulik , A , Mielczarski , J , Kiwi , J . Photodynamics and surfacecharacterization of TiO 2 and Fe 2 O 3 photocatalysts immobilized on modified polyethylene films . J
Authors:Y. A. El-Shekeil, S. M. Sapuan, A. Khalina, E. S. Zainudin, and O. M. Al-Shuja'a
. Surfacecharacterization was perused. SEM and FTIR spectroscopy were carried out to observe the effect of NaOH treatment on fibers and on composites as well. TG and DSC thermal studies have been conducted to further investigate the effect of NaOH on the