Nanoparticles (NPs) may have great potential for various subsurface applications, including oil and gas recovery, reservoir imaging, and environmental remediation. One of the important challenges for these downhole applications is to achieve colloidal stability in subsurface media at high salinity and high temperature. It has been previously shown that several functional NPs "multipoint"-grafted with anionic poly(2-acrylamido-2-methyl-1-propanesulfonate--acrylic acid; AMPS--AA) exhibited remarkable colloidal stabilities in specific environments mimicking the harsh subsurface aquatic media, such as the American Petroleum Institute (API) brine. However, many important properties of such particles, other than the colloidal stabilities, must be studied in a more systematic fashion for a wide range of salt concentrations (). Herein, we investigate various properties of the silica (SiO) NPs multipoint-grafted with poly(AMPS--AA), SiO--poly(AMPS--AA), in NaCl and CaCl solutions across a range of salinities. The brush behavior of the grafted random copolymers was investigated in both salt solutions from salt-free conditions up to extreme salinities. The particles displayed brine-oil interfacial activity with increasing , stabilizing oil-in-brine emulsions as Pickering emulsifiers. A high internal phase emulsion (HIPE) with an internal oil phase of up to 80 vol % could be formed in CaCl solutions at high , which exhibited gel-like behaviors.
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http://dx.doi.org/10.1021/acs.langmuir.9b03692 | DOI Listing |
ACS Nano
December 2024
Department of Chemistry, University of California, Berkeley, California 94720, United States.
Characterizing the size, structure, and composition of nanoparticles is vital in predicting and understanding their macroscopic properties. In this work, charge detection mass spectrometry (CDMS) was used to analyze nanocapsules (∼10-200 MDa) consisting of a liquid oleic acid core surrounded by a dense silica outer shell. CDMS is an emerging method for nanoparticle analysis that can rapidly measure the mass and charge of thousands of individual nanoparticles.
View Article and Find Full Text PDFJ Sep Sci
December 2024
College of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming, China.
Chiral macrocycles have emerged as attractive media for chromatographic enantioseparation due to their excellent host-guest recognition properties. In this study, a new chiral stationary phase (CSP) based on 1,1'-binaphthyl chiral polyimine macrocycle (CPM) was reported. The CPM was synthesized by one-step aldehyde-amine condensation of (S)-2,2'-dihydroxy-[1,1'-binaphthalene]-3,3'-dicarboxaldehyde with 1,2-phenylenediamine and bonded on thiolated silica via the thiol-ene click reaction to afford the CSP.
View Article and Find Full Text PDFAnal Chem
December 2024
Department of Chemistry, National Demonstration Centre for Experimental Chemistry Education, Yanbian University, Yanji City 133002, Jilin Province, China.
Generally, the traditional stationary phase for liquid chromatography is the key part, but with an in situ immutable property, leading to many separation limitations. Based on the former exploration of photosensitive gas chromatography, we successfully prepared a photosensitive monolithic capillary silica column with high light transmission, taking advantage of the reversible cis-trans isomerism of azobenzene. And the cis-trans isomerism has launched an effective, reversible, and precise control on the liquid chromatographic retention behavior just by photoinduction according to the theoretical basis of a good correlation between photoinduction time, -azobenzene ratio, and chromatographic retention factor () ( > 0.
View Article and Find Full Text PDFHuan Jing Ke Xue
January 2025
College of Environmental and Resource Sciences, Zhejiang A&F University, Lin'an 311300, China.
Cadmium (Cd) and arsenic (As) often coexist in water and agricultural soils around mining areas, and it is difficult to remove them at the same time due to their opposite chemical behaviors. Therefore, this study employed a co-precipitation-pyrolysis method to synthesize silica-based magnetic biochar (SMB) materials for the remediation of water contaminated with both Cd and As. The optimization of preparation conditions involved introducing three different types of silicates (NaSiO, CaSiO,and SiO) into the biomass-magnetite mixture, followed by pyrolysis at various temperatures (300℃, 500℃, and 700℃), and the optimal preparation conditions were determined based on the composite batch experiments.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
Department of Vascular Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China. Electronic address:
Abdominal aortic aneurysm (AAA) is a chronic inflammation-driven disease characterized by aortic wall destruction and expansion, leading to high morbidity and mortality. However, previous drug treatments for its common risk factors have not achieved favorable results, and the early prevention and treatment is still the main clinical dilemma. Anti-inflammation therapy is a promising therapeutical method targeting its pathogenesis mechanism, but it has not been explored in depth.
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