Search results for "dioxide"
showing 10 items of 1250 documents
Photoluminescence and Electron Spin Resonance of Silicon Dioxide Crystal with Rutile Structure (Stishovite)
2018
This work was supported by ERANET MYND. Also, financial support provided by Scientific Research Project for Students and Young Researchers Nr. SJZ/2017/2 realized at the Institute of Solid State Physics, University of Latvia is greatly acknowledged. The authors express our gratitude to R.I. Mashkovtsev for help in ESR signal interpretation. The authors are appreciative to T.I. Dyuzheva, L.M. Lityagina, N.A. Bendeliani for stishovite single crystals and to K. Hubner and H.-J. Fitting for stishovite powder of Barringer Meteor Crater.
A one-pot method to enhance dissolution rate of low solubility drug molecules using dispersion polymerization in supercritical carbon dioxide
2009
Preparation of pH sensitive poly(vinilydenefluoride) porous membranes by grafting of acrylic acid assisted by supercritical carbon dioxide
2010
Aim of this work is to study the preparation of pH sensitive membranes for biomedical applications via thermal induced graft polymerization of acrylic acid (AA) on poly(vinilydenefluoride) (PVDF) assisted by supercritical carbon dioxide (scCO2). Using scCO2 as a solvent and swelling agent, the monomer and initiator (benzoyl peroxide) could diffuse faster and distribute more uniformly into the polymer matrix. A better control of the final molecular architecture should be achieved because bimolecular grafting reactions are accelerated with respect to chain degradation processes. Commercial hydrophobic PVDF porous matrixes were selected as model membranes. Grafted polymers were characterized b…
Melt phase ring opening polymrization of lactide and glycolide assisted by supercritical carbon dioxide
2010
Supercritical carbon dioxide induces sterilization of PLLA scaffolds contaminated by E. coli.
2014
The common sterilization techniques are based on physical processes that involve, for example, the use of autoclaves or systems to radiation such as γ-rays that can cause a structural change of the polymer treated. Therefore, the use of supercritical carbon dioxide (scCO2) is an excellent alternative, as it does not induce any variation of biomaterials treated (Perrut M., 2012). It's a good candidate because is readily available at low cost, non-toxic and non-flammable, it has an easily accessible critical point (7.38 MPa and 304.2 K) and excellent transport properties and wettability (White A. et al., 2005). We report the development of a supercritical CO2 based process capable of steriliz…
Modeling Heterogeneous copolymerization in scCO2
2008
Active degassing of crustal CO2 in areas of tectonic collision: A case study from the Pollino and Calabria sectors (Southern Italy)
2022
Carbon dioxide (CO2) is released from the Earth’s interior into the atmosphere through both volcanic and non-volcanic sources in a variety of tectonic settings. A quantitative understanding of CO2 outgassing fluxes in different geological settings is thus critical for decoding the link between the global carbon budget and different natural processes (e.g., volcanic eruption and earthquake nucleation) and the effects on the climate evolution over geological time. It has recently been proposed that CO2 degassing from non-volcanic areas is a major component of the natural CO2 emission budget, but available data are still sparse and incomplete. Here, we report the results of a geochemical surve…
Formation of Si/SiO2 Luminescent Quantum Dots From Mesoporous Silicon by Sodium Tetraborate/Citric Acid Oxidation Treatment
2019
We propose a rapid, one-pot method to generate photoluminescent (PL) mesoporous silicon nanoparticles (PSiNPs). Typically, mesoporous silicon (meso-PSi) films, obtained by electrochemical etching of monocrystalline silicon substrates, do not display strong PL because the silicon nanocrystals (nc-Si) in the skeleton are generally too large to display quantum confinement effects. Here we describe an improved approach to form photoluminescent PSiNPs from meso-PSi by partial oxidation in aqueous sodium borate (borax) solutions. The borax solution acts to simultaneously oxidize the nc-Si surface and to partially dissolve the oxide product. This results in reduction of the size of the nc-Si core …