Silica colloids were separated by size-exclusion chromatography and monitored by fluorimetric and UV detection. In the former means of detection, silica colloids were visualized by light-scattering. The signal intensity based on the light scattering increased with increasing size of the silica colloids. The maximum intensity was observed at excitation wavelengths around 270-290nm. In UV detection, silica colloids were visualized based on turbidimetry, and the signal intensity also increased with increasing size of the silica colloids and with decreasing detection wavelength. The signal intensities for both light-scattering and turbidimetric detection were a linear function of the concentration of the silica colloids. The detection limit at S/N = 3 for 78-nm colloids was 0.06 ppm for light-scattering detection whereas the LOD was 2.3 ppm for UV detection. Effects of mobile phase conditions and flow rate on resolution and peak shape were examined. Use of phosphate buffer allowed the separation of silica colloids of different sizes in size-exclusion chromatography.
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http://dx.doi.org/10.1007/s00216-008-2017-9 | DOI Listing |
Langmuir
January 2025
Department of Chemistry, The University of Utah, Salt Lake City, Utah 84112, United States.
Slip flow, a fluid flow enhanced in comparison to that calculated using continuum equations, has been reported for many nanopores, mostly those with hydrophobic surfaces. We investigated the flow of water, hexane, and methanol through hydrophilic nanopores in silica colloidal crystals. Three silica sphere sizes were used to prepare the crystals: 150 ± 30, 500 ± 40, and 1500 ± 100 nm.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao 266237, P. R. China.
Membrane distillation (MD) efficiently desalinizes and treats high-salinity water as well as addresses the challenges in handling concentrated brines and wastewater. However, silica scaling impeded the effectiveness of MD for treating hypersaline water and wastewater. Herein, the effects of humic acid (HA) on silica scaling behavior during MD are systematically investigated.
View Article and Find Full Text PDFACS Nano
January 2025
Center for Innovation & Precision Dentistry, School of Dental Medicine, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
Microrobots are poised to transform biomedicine by enabling precise, noninvasive procedures. However, current magnetic microrobots, composed of solid monolithic particles, present fundamental challenges in engineering intersubunit interactions, limiting their collective effectiveness in navigating irregular biological terrains and confined spaces. To address this, we design hierarchically assembled microrobots with multiaxis mobility and collective adaptability by engineering the potential magnetic interaction energy between subunits to create stable, self-reconfigurable structures capable of carrying and protecting cargo internally.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
Department of Materials Science and Engineering, Shaanxi Province Key Laboratory of Corrosion and Protection, Xi'an University of Technology, Xi'an 710048 PR China.
Pitting corrosion caused by sulfate-reducing bacteria (SRB) significantly shortens the lifespan of metallic pipelines. Antibacterial coatings containing S-responsive drug-loaded nanocontainers represent a promising method to mitigate SRB corrosion. However, the challenge of balancing rapid bactericide release with continuous antibacterial effect limits their practical application.
View Article and Find Full Text PDFFood Chem
January 2025
College of Food Science and Technology, Bohai University, Jinzhou 121013, China.
To enhance the surface hydrophobicity and emulsification capacity of silica colloidal particles, a natural surface modification of soy hull polysaccharides (SHP) was conducted. Here, the effects of pH and ionic strength on the stability, microstructure and rheological properties of concentrated Pickering emulsions were investigated. Experimental results show emulsions gelled at pH 2, with increasing pH (2-10), SiO-SHP absolute zeta potential (from -19.
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