Enthalpy and entropy of adsorption of light hydrocarbons C1-C4 have been measured for three monoliths of different polarity and for five different carrier gases: helium, hydrogen, nitrogen, carbon dioxide and dinitrogen oxide. Using carrier gas helium the highest values of enthalpy and entropy were observed for monolith based on ethylenedimethacrylate and the lowest values were observed for monolith based on silica, while monolith based on divinylbenzene demonstrated intermediate values. Entropy-enthalpy correlations were observed with carrier gas helium for all thee monoliths and possess similar slope indicating similar adsorption mechanism on all monoliths studied. Comparing different carrier gases entropy-enthalpy correlations within a homological series of solutes were observed for light carrier gases (He, H2 and N2) and were not observed for heavy carrier gases (CO2 and N2O). Instead, entropy-enthalpy correlations for heavy carrier gases were observed with pressure as variable and the higher the carrier gas pressure the lower the values of enthalpy and entropy observed. The observed changes in entropy-enthalpy correlations were explained by competitive adsorption of heavy carrier gas on monoliths.
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http://dx.doi.org/10.1002/jssc.201100162 | DOI Listing |
Cold atmospheric pressure plasma (CAPP) comprises an ensemble of ionized gas, neutral particles, and/or reactive species. Electricity is frequently used to produce CAPP via a variety of techniques, including plasma jets, corona discharges, dielectric barrier discharges, and glow discharges. The type and flow rates of the carrier gas(es), temperature, pressure, and vacuum can all be altered to control the desired properties of the CAPP.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
Department of Chemical Engineering, Guangdong Technion - Israel Institute of Technology, 241 Daxue Road, Shantou, Guangdong 515063, China.
Facilitated transport membranes (FTMs) with an ultraselective layer prepared from amine-rich polyvinylamine (PVAm)/2-(1-piperazinyl)ethylamine salt of sarcosine (PZEA-Sar) (denoted by PM) and an amorphous dendritic cross-linked network of PVAm-functionalized poly(ethylene glycol)diglycidyl ether (PEGDGE) (named PP) were designed for CO separations. The developed membranes expedited CO transport over N through the synergistic effect from the induced CO-philic ethylene oxide groups and highly hydrophilic and polar hydroxyl groups together with the low-crystallinity PP networks, which offer a high diffusion rate for CO-amine complexes through the membrane and stabilize small molecular mobile carriers via hydrogen bonding. The best (PM/PP-10)/polysulfone (PSf) composite membranes achieved a superior CO/N selectivity of 230 (4.
View Article and Find Full Text PDFAnal Chem
December 2024
State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
A novel approach for determining the elemental content of organic matter through thermal gravimetric analysis coupled online with a mass spectrometer (TG-MS) is disclosed. This method not only yields results equivalent to ASTM analysis but also provides insight into the covalent bond structure within the sample. The principle of this technique consists of the combustion of organic matter in an oxygen-enriched environment within the thermogravimetric (TG) system.
View Article and Find Full Text PDFIn large-area quantum networks based on optical fibers, photons are the fundamental carriers of information as so-called flying qubits. They may also serve as the interconnect between different components of a hybrid architecture, which might comprise atomic and solid-state platforms operating at visible or near-infrared wavelengths, as well as optical links in the telecom band. Quantum frequency conversion is the pathway to change the color of a single photon while preserving its quantum state.
View Article and Find Full Text PDFTransplantation
January 2025
Department of Urology and Transplantation Surgery, Nantes University Hospital, Nantes, France.
Background: The clinical standard for pancreas preservation for transplantation is static cold storage (SCS). Oxygenation during preservation has been shown to be advantageous in clinical studies. This study evaluates the efficiency of different oxygenation modalities during hypothermic pancreas preservation.
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