Search results for "poros"
showing 10 items of 1076 documents
An ultrathin suspended hydrophobic porous membrane for high-efficiency water desalination
2017
Abstract An ultrathin highly fluorinated porous membrane was designed for a large production of desalted water at very low energy consumption. Imprinting water droplets were used through a low thermally conductive tetra-fluoroethylene (TFE)/2,2,4-trifluoro-5-tri-fluorometoxy-1,3-dioxol (TIT) (HYFLON AD 60) solution and the generated porous nanofilm was suspended onto a polyethersulfone (PES) honeycomb texture. The very tiny fluorinated thickness together with a large number of small-shaped pores provided the membrane for enhanced anti-wetting surface properties, extremely reduced resistance to water vapor transfer and outstanding thermal efficiency. Fine materials structure-transport relati…
Structure and performance properties of environmentally-friendly biocomposites based on poly(ɛ-caprolactone) modified with copper slag and shale dril…
2018
The potential application of two types of industrial wastes, drill cuttings (DC) and copper slag (CS), as silica-rich modifiers of poly(ɛ-caprolactone) (PCL) was investigated. Chemical structure and physical properties of DC and CS fillers were characterized using X-ray diffractometer, X-ray fluorescence spectroscopy, particle size and density measurements. PCL/DC and PCL/CS composites with a variable content of filler (5 to 50 parts by weight) were prepared by melt compounding in an internal mixer. It was observed that lower particle size of DC filler enhanced processing of biocomposites comparing to CS filler. Smaller particles of DC filler and thus the higher specific surface area, enabl…
Tin-based mesoporous silica for the conversion of CO2 into dimethyl carbonate.
2011
Sn-based SBA-15 was prepared by reacting di-n-butyldimethoxystannane with SBA-15 pretreated with trimethylchlorosilane (TMCS) to cap the external hydroxyl groups. Small-angle X-ray diffraction (SXRD), infrared spectroscopy (IR), nitrogen adsorption/desorption, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and inductively coupled plasma atomic emission (ICP-AES) measurements allow us to propose that the organotin species are located within the pore channels of the mesoporous host. This novel material catalyzes selectively the coupling of CO(2) with methanol to dimethyl carbonate (DMC). The reaction time-conversion dependence shows that a turnover number (TON) of 1…
Preparation, characterization and in vitro test of composites poly-lactic acid/hydroxyapatite scaffolds for bone tissue engineering.
2018
Abstract In this work, the possibility to produce composite Poly-L-lactic acid (PLLA)/Hydroxyapatite (HA) porous scaffolds via Thermally Induced Phase Separation (TIPS) for bone tissue engineering applications was investigated. Several PLLA/HA wt/wt ratios (95/5, 90/10, 70/30, 50/50, 34/66) were tested and the as-obtained scaffolds were characterized via Scanning Electron Microscopy, Wide Angle X-Ray Diffraction, Thermogravimetric analysis, Gas Pycnometry, Differential Scanning Calorimetry and mechanical compression test. Morphological analysis revealed an open structure with interconnected pores and HA particles embedded in the polymer matrix. Finally, cell cultures were carried out into t…
Effect of halloysite nanotubes filler on polydopamine properties
2019
Abstract Hypothesis Polydopamine (PDA) is widely used as hydrophilic coating for several applications. However, most of the methods studied to improve or manipulate PDA properties are multistep and time-consuming, and there is a need for versatile strategies aimed at controlling and modifying the properties of PDA. Experiments PDA-halloysite nanocomposites were produced under different oxidation conditions in alkaline and acidic media and were characterized by UV–visible and attenuated total refraction- Fourier Transform Infrared spectroscopies, thermogravimetric analysis, porosimetry, scanning electron microscopy, X-ray diffraction and contact angle measurements against the reference PDA p…
Gravimetric characterisation of the surface properties of a porous drug carrier
1995
The gas adsorption method is the most common means to characterise the topology of solid surfaces with regard to its use as an adsorbent. Adsorption isotherms are determined advanta-geously using a vacuum microbalance: Thermogravimetric techniques allow the observation of sample degassing and its optimization. The dry mass is determined in situ, the mass of gas adsorbed is measured directly and different gases can be used without calibration. From the isotherm the pore size distributions, specific surface area, fractal dimension and density can be derived. Commercially available gravimetric sorption apparata and vacuum balances as well as software for data evaluation are reviewed in tables.…
Differences of raw cork quality in productive cork oak woods in Sicily in relation to stand density
2010
Differences of raw cork quality, in terms of thickness and porosity, were observed in productive cork oak (Quercus suber L.) stands in the Nebrodi and Iblei mountains of Sicily in relation to stand density. Five study areas were chosen across a range of different stand density satisfying specific sampling requirements among two managed cork oak stands. Analysis of variance using Fisher-Snedecor's F test (p<0,05) were used to identify statistically significant differences of cork quality and sylvicultural, dendrometric and cork stripping parameters between study areas within each stand and also between stands. Relationships between cork quality and sylvicultural and dendrometric parameters w…
Reconsidering the accuracy of X-ray fluorescence and ion beam based methods when used to measure the thickness of ancient gildings
2017
Since at least 5000 years ago, gilding techniques have been used for decoration purposes or to make artefacts appear as made of solid gold. Investigation of ancient gildings inevitably requires measuring their thickness, which is usually done either through the observation of cross-sections or by methods such as Rutherford backscattering spectroscopy, particle-induced X-ray emission and X-ray fluorescence. Whereas the former method requires sampling, the latter ones are non-invasive and therefore preferable. These non-invasive methods, however, measure the number of atoms per unit area, which can be converted into thickness only if the density is known. So far this has not been considered a…
Cs0.86(NH41.14SO4Te(OH)6 in porous anodic alumina for micro fuel cell applications.
2011
Abstract Cs0.86(NH4)1.14SO4Te(OH)6 supported by anodic alumina membranes (AAMs) has been characterized for the first time in H2/O2 fuel cell. The fabricated membrane electrode assemblies are able to produce peak power densities in the range 15–30 mW cm−2 under mild conditions (room temperature, low humidity and low Pt loading) and show an increased durability with cycling with respect to previous results obtained with AAM-based fuel cell. The physico-chemical characterization of the electrolytes has been carried out through X-ray diffractometry, scanning electron microscopy and micro-raman analysis. An estimation of the composite membranes conductance under fuel cell operation has been carr…
Impact of sedimentology and diagenesis on the petrophysical properties of a tight oolitic carbonate reservoir. The case of the Oolithe Blanche Format…
2013
18 pages; International audience; The Oolithe Blanche Formation was studied in three quarries, located at the south-eastern edge of the Paris Basin (France). Heterogeneities in reservoir properties were assessed through a sedimentological, diagenetic and petrophysical study. The relationships between depositional settings, diagenesis and petrophysical properties were analysed using detailed petrographic studies, image analysis, Nano CTscans and petrophysical measurements. The carbonate reservoir pore network is mainly controlled by intraparticle microporosity which ensures the connectivity with interparticle meso- and macroporosity. Early cementation vs. early compaction processes (mainly g…