NMR self-diffusion and relaxation, coupled with viscosity, were used to study the properties and structure of two imidazolium-based ionic liquids, 1-ethyl-3-methylimidazolium acetate [C2MIM][OAc] and 1-ethyl-3-methylimidazolium octanoate [C2MIM][OOct]. The experimental results point to the formation of different types of aggregates in each ionic liquid. These aggregates are small and stable under flow and temperature in [C2MIM][OAc], whereas the aggregates are large and sensitive to flow and temperature in [C2MIM][OOct]. In the latter case the size of aggregates decreases both under flow and temperature increase.
Novel carbon molecular sieve membranes with high separation performance and stability in the presence of humidified streams were prepared from an optimized ionic liquid-regenerated cellulose precursor, in a single carbonization step. Membranes prepared at two different carbonization end temperatures (550°C and 600°C) were analyzed through scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, carbon dioxide adsorption and permeation experiments. The prepared membranes exhibited uniform thickness of approximately 20 µm and a well-developed microporous structure. The permeation performance of these carbon molecular sieve membranes was above the Robeson upper bound curve for polymeric membranes. In particular, the membrane prepared at 550°C end temperature exhibited permeability to oxygen of 5.16 barrer and O 2 /N 2 ideal selectivity of 32.3 and permeability to helium of 126 barrer and He/N 2 ideal selectivity of 788; besides, permeation experiments performed in the presence of ca. 80% relative humidity showed that humidity does not originate pore blockage. These results open the door for the preparation of tailor made precursors that originate carbon molecular sieve membranes with extraordinary separation performances, mechanical resistance and stability. [21], poly(furfuryl alcohol) [22,23], phenolic resins [24-28], resorcinol-formaldehyde resin [29][30][31][32] and cellulose [16,[33][34][35]. Recently, our group applied for a patent of a process for obtaining, in a single carbonization step, CMSM that display no pore blockage effect in
For some time, carbon molecular sieve membranes (CMSMs) have been promoted as energy‐efficient candidates for gas separation due to their high selectivity, permeability, and stability in chemically aggressive environments. Nevertheless, these membranes have not yet been made into commercial products due to a significant decrease in performance when exposed to humidity and/or oxygen. Herein, disruptive CMSMs with extremely high separation performance and stability, even in the presence of humidity, are reported. The carbon membranes are prepared from a renewable, low‐cost precursor with a single carbonization step. Water vapor adsorption/desorption studies demonstrate that these membranes have a linear water vapor adsorption isotherm, characteristic of a homogeneous distribution of hydrophilic sites on the pore surfaces, allowing for water molecules to hop continuously between sites and avoiding the formation of pore‐blocking water clusters. These results are a breakthrough toward bringing this new type of membrane to a commercial level.
Solutions of glucose, cellobiose, and microcrystalline cellulose in the ionic liquid 1-ethyl-3-methyl-imidazolium acetate ([C2mim][OAc]) have been examined using low-field (20 MHz) NMR relaxometry and rheology. The spin-lattice ( T) and spin-spin ( T) relaxation times have been determined from 30 to 70 °C inclusive, for a range of concentrations (0-15 wt %) of each carbohydrate in [C2mim][OAc]. The zero shear rate viscosities for the same samples across the same temperature range were studied. The viscosity, NMR relaxometry, and previously published diffusion data were all analyzed together through the Debye-Stokes-Einstein equations. Microscopically, these systems behave as an "ideal mixture" of free ions and ions associated with the carbohydrate molecules. The molar ratio of carbohydrate OH groups to ionic liquid molecules, α, is the key parameter in determining the NMR relaxometry and hence the local microscopic environment of the ions. NMR relaxometry data are found to follow an Arrhenius type behavior, and the difference in rotational activation energy between free and associated ions is determined at 6.2 ± 0.5 kJ/mol.
The objective of this study was to detect Mycoplasma bovis specific antibodies using a recently reported MilA ELISA with the aim to detect M. bovis antibodies in milk. An indirect ELISA, based on a recombinant fragment of the Mycoplasma immunogenic lipase A (MilA) protein, was conducted on 291 milk samples for the detection of M. bovis antibodies. Samples were also tested with conventional Mycoplasma culture and M. bovis PCR. Samples were collected from individual cows from 2 commercial dairy herds in South Australia. Of 291 samples tested, 68 (23.4%) were detected positive for M. bovis antibodies, 150 (51.5%) were positive for M. bovis in PCR and 166 (57.0%) in bacterial culture. These results indicate that MilA indirect ELISA can be utilized for the detection of M. bovis antibodies in milk.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.