This paper overviews silica suspensions in water-immiscible liquids, with an emphasis on their dispersion stability and rheological properties as a function of the surface characteristics of silica powders at lower silica volume fractions, ϕ, than 0.1. In addition, a critical review is presented the manufacturing process of silica powder by considering their microstructures. Hydrophilic fumed silica powders are in a gel state at lower ϕ than hydrophobic fumed silica powders in water-immiscible liquids. The interaction between the surface silanol groups is dominant in the former; whereas in the latter, the mutual interaction between the surface hydrophobic moieties and the dispersion media is favored. Moreover, the dynamic moduli of the hydrophobic fumed silica suspensions strongly depend on the mutual interaction between the hydrophobic moieties and the dispersion media. Their magnitudes become larger as mutual interactions increase. In addition, the effects of the adsorption of polymers and non-adsorbing polymers on the dispersion stability and rheological behavior of hydrophilic or hydrophobic fumed silica suspensions are discussed, by considering their small-angle neutron scattering (SANS) curves. The precipitated silica suspensions are more compact and form smaller microstructures than the fumed silica suspensions and their gels correspond to the weak-link gel.
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http://dx.doi.org/10.1016/j.cis.2020.102139 | DOI Listing |
Soft Matter
January 2025
James Franck Institute and Department of Physics, The University of Chicago, Chicago, Illinois 60637, USA.
We measure the response of open-cell polyurethane foams filled with a dense suspension of fumed silica particles in polyethylene glycol at compression speeds spanning several orders of magnitude. The gradual compressive stress increase of the composite material indicates the existence of shear rate gradients in the interstitial suspension caused by wide distributions in pore sizes in the disordered foam network. The energy dissipated during compression scales with an effective internal shear rate, allowing for the collapse of three data sets for different pore-size foams.
View Article and Find Full Text PDFRapid Commun Mass Spectrom
April 2025
Department of Civil and Environmental Engineering, Syracuse University, Syracuse, New York, USA.
Rationale: The complexation with dissolved organic matter (DOM) is a pivotal factor influencing transformations, transport, and bioavailability of mercury (Hg) in aquatic environments. However, identifying these complexes poses a significant challenge because of their low concentrations and the presence of coexisting ions.
Methods: In this study, mercury-dissolved organic matter (Hg-DOM) complexes were isolated through solid-phase extraction (SPE) from Hg-humic acid suspensions, and complexes were putatively identified using ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS).
Acta Pharm
December 2024
University of Zagreb Faculty of Pharmacy and Biochemistry 10000 Zagreb, Croatia.
Zeolites are a large family of minerals and the most studied is the naturally occurring clinoptilolite. They possess anti-inflammatory, antioxidant, and detoxifying properties which makes them valuable for medicinal use. Element analysis of zeolite's composition is necessary for its precise chemical characterization, and within this work development of a suspension method for the determination of manga nese, iron, and zinc by total reflection X-ray fluorescence spec-trometry (TXRF) was presented.
View Article and Find Full Text PDFJ Funct Biomater
December 2024
Department of Pharmaceutics, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
CY1-4, 9-nitropyridine [2',3':4,5] pyrimido [1,2-α] indole -5,11- dione, is an indoleamine 2,3-dioxygenase (IDO) inhibitor and a poorly water-soluble substance. It is very important to increase the solubility of CY1-4 to improve its bioavailability and therapeutic effect. In this study, the mesoporous silica nano-skeleton carrier material Sylysia was selected as the carrier to load CY1-4, and then the CY1-4 nano-skeleton drug delivery system (MSNM@CY1-4) was prepared by coating the hydrophilic polymer material Hydroxypropyl methylcellulose (HPMC) and the lipid material Distearoylphosphatidyl-ethanolamine-poly(ethylene glycol) (DSPE-PEG) to improve the anti-tumor effect of CY1-4.
View Article and Find Full Text PDFPolymers (Basel)
November 2024
State Key Laboratory of High-Performance Precision Manufacturing, School of Mechanical Engineering, Dalian University of Technology, Dalian 116024, China.
Microfluidic devices offer promising solutions for automating various biological and chemical procedures. Epoxy resin, known for its excellent mechanical properties, chemical resistance, and thermal stability, is widely used in high-performance microfluidic devices. However, the poor printability of epoxy has limited its application in 3D printing technologies for fabricating epoxy-based microfluidic devices.
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