Screening method for differentiation of plastic and non-plastic microparticles contaminating store-bought rice.

This article presents a simple and low-cost screening method based on optical microscopy and FT-IR spectroscopy for assessing microparticles found in rice. Five brands of rice packed in paper and foil bags from both the European Union (EU) and non-EU region were tested. Microparticles of various shapes have been found in the rice regardless of the packaging type and origin of the rice.

The Removal of Arsenic and Its Inorganic Forms from Marine Algae-A Base for Inexpensive and Efficient Fertilizers.

Newly synthesized cerium oxide was successfully obtained by the hard templating route. The optimal As(III) and As(V) adsorption onto the studied adsorbent was reached for the initial pH of 4.0 and a contact time of 10 h.

Influence of different confining matrices on negative pressure in liquid n-heptane investigated using positronium bubbles as a probe.

Hypothesis: The negative pressure in liquids under the concave meniscus of nanometer size can be observed experimentally. This allows verification of the predictions of the macroscopic Young-Laplace law, which has so far been performed only on the basis of theoretical calculations. The deviation of the negative pressure from the Young-Laplace law allows to get information about the structure of the porous matrix.

Polymer-amino-functionalized silica composites for the sustained-release multiparticulate system.

This study presents an interesting and promising strategy for producing an oral multiparticulate formulation of the sustained-release of diclofenac sodium (DS) consisting of subunits closed inside hard gelatin capsules (each capsule contains ~50mg of diclofenac sodium). The subunits in the form of beads were produced through the encapsulation of diclofenac sodium dispersed within a nondisintegrating polymer carrier by a silica gel functionalized with the 3-aminopropyl groups. The hybrid silica gel, which plays the role of enteric coating, was fabricated by the gelation of the liquid silica precursors mixture (i.

Vapour-phase method in the synthesis of polymer-ibuprofen sodium-silica gel composites.

The study discusses the synthesis of polymer-silica composites comprising water soluble drug (ibuprofen sodium, IBS). The polymers selected for this study were poly(TRIM) and poly(HEMA--TRIM) produced in the form of permanently porous beads via the suspension-emulsion polymerization method. The acid and base set ternary composites were prepared by the saturation of the solid dispersions of drug (poly(TRIM)-IBS and/or poly(HEMA--TRIM)-IBS) with TEOS, and followed by their exposition to the vapour mixture of water and ammonia, or water and hydrochloric acid, at autogenous pressure.

Positron insight into evolution of pore volume and penetration of the polymer network by n-heptane molecules in mesoporous XAD4.

The adsorption and desorption of n-heptane on the mesoporous polymer resin Amberlite XAD4 were investigated in situ by positron annihilation lifetime spectroscopy (PALS). This technique allows the monitoring of porosity and subnanometer free volume changes as well as the amount of liquid adsorbate captured within an investigated sorbent, without causing any interference with the course of adsorption/desorption. In consequence, the conducted studies provide microscale insight into the sorption processes of n-heptane (which is a significant component of volatile organic compounds - VOCs) on the polymeric material.

Encapsulation of diclofenac sodium within polymer beads by silica species via vapour-phase synthesis.

The present study concerns the preparation of ternary composites via the in situ encapsulation of solid dispersion of diclofenac sodium within the acrylic polymer beads. The encapsulating species were produced through the hydrolysis and condensation of the silica precursors (tetraethoxysilane or ethyltriethoxysilane) introduced into the solid dispersion. The transformation of precursors occurred in the vapor phase of ammonia.

Insight into the structure of polymer-silica nano-composites prepared by vapor-phase.

Using a new synthesis technique, in which mesoporous Amberlite XAD7HP resin beads swollen with TEOS were exposed to vapors of either (H2O+HCl) or (H2O+NH3), we obtained smooth, porous, mechanically stable silica gel spheres after burning out the sacrificial organic template. Combined N2 sorption, SEM, TEM, (29)Si NMR, and Raman measurements were used to characterize the physical properties and molecular structures of the intermediate and final gels. Our atomically resolved TEM pictures provide the first visual demonstration of the presence of 3 to 6 member siloxane rings predicted by our Raman studies and other indirect methods.

Synthesis of aspirin-loaded polymer-silica composites and their release characteristics.

This study describes a novel approach to the synthesis of polymer-drug-silica nanocomposites via encapsulation/isolation of drug molecules, introduced into the polymer matrix by the silica gel. For the first time, tetraethoxysilane (TEOS) gelation in the vapor phase of the acidic catalyst is presented as an efficient method to enter the silica gel nanoparticles into the polymer-aspirin conjugate. The conducted studies reveal that the internal structure of the polymer carrier is significantly reorganized after the embedding of aspirin molecules and the silica gel.

Synthesis and characterization of nanostructural polymer-silica composite: positron annihilation lifetime spectroscopy study.

The swelling of poly(TRIM) spherical particles in TEOS is assessed as a potential way for obtaining polymer-silica nanocomposite materials. Silica deposition was achieved by simply stirring of swollen polymer particles in acidic hydrochloric-water solution. This procedure leads to spherical composite particles with dispersed silica gel within the polymer matrix.

Polymer/silica composite of core-shell type by polymer swelling in TEOS.

Monodisperse polymer/silica composite material with a polymer as the core and hydrophilic silica gel as the shell was prepared by a two-stage procedure. In the first stage, the swelling of Amberlite XAD7HP particles in tetraethoxysilane (TEOS) was performed. Subsequently a portion of the XAD7HP particles impregnated with TEOS were transferred to acidic aqueous solution to facilitate a sol-gel process of the silica precursor.