The polyelectrolyte adsorption on colloid particles is often used for stabilization or flocculation of water suspensions. The aim of this work is to study the adsorption of carboxymethyl cellulose (CMC) on alumina (γ-Al2O3) colloid particles. The particles and polymer are chosen because of the capability of the metal-oxide ampholyte surface and the weak polyelectrolytes to alter their charge by pH. The measurements are done at pH 6.0 where the CMC carboxylic gropes are almost fully dissociated and the alumina surface is positively charged. The high linear charge density of the polyelectrolyte chain provides Na(+) counterions condensation on the COO(-) groups. The main employed method is the electric light scattering based on particle orientation in sinusoidal electric field. The electric polarizability and the relaxation time after field switching off (both depending on the particle charge and size) are used as criteria for polymer adsorption and particle aggregation. Micro-electrophoresis is applied as additional techniques indicating the sign and density of the surface charge. The results obtained give the conditions (time dependence, particle and polymer concentrations) where the CMC adsorption is complete and the suspension is stable.
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http://dx.doi.org/10.1016/j.jcis.2014.11.051 | DOI Listing |
J Environ Manage
January 2025
Department of Soil Science and Agricultural Chemistry, Engineering Polytechnic School, University of Santiago de Compostela, 27002, Lugo, Spain.
The primary goal of the current work was to construct pH-sensitive nano and microcomposite hydrogel beads based on alginate (AL), carboxymethyl cellulose (CMC), biochar (BC), and two Moroccan clays: Ghassoul (swelling SW) and red (not swelling NSW) nano and microhybrid. The adsorbents, SW + AL, SW + AL + BC, SW + AL + CMC, NSW + AL, NSW + AL + BC, NSW + AL + CMC, AL, and AL + CMC were prepared for the adsorption of the antibiotic sulfadiazine (SDZ). The test samples were characterized using a variety of techniques, including X-Ray Diffraction (XRD), IR spectroscopy (FT-IR), and scanning electron microscopy (SEM), with the molecular structures of the studied additives geometrically optimized using the DFT/B3LYP method and the function 6-311G(d).
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
School of Materials Science and Art and Design, Inner Mongolia Agricultural University, Hohhot 010018. China; Laboratory of Fibrosis and Energy Utilization of Shrubby Resources in Inner Mongolia Autonomous Region, China; National Forestry Grassland Engineering Technology Research Center for Efficient Development and Utilization of Sandy Shrubs, China. Electronic address:
A new, effective powdered adsorbent (CMCFe) for removing oxytetracycline (OTC) was synthesized successfully in an acidic environment using a thermal fusion technique. CMC-Fe underwent comprehensive SEM, EDS, FT-IR, XRD, XPS, TGA, and BET analyses before and after adsorbing OTC. These studies systematically examined preparation variables such as CMC and FeCl ratios, acetic acid quantity, reaction duration, and temperature.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
College of Materials Science and Engineering, Nanjing Tech University, Nanjing 211816, PR China. Electronic address:
The carboxymethyl chitosan (CMCS)-based porous beads are still criticized for their limited number of binding sites, which impairs their efficacy in removing aqueous pollutants. To overcome this challenge, this work introduces the production of covalently crosslinked CMCS-based beads containing SiO and poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS). The porous composite beads not only possess remarkable stability under acidic conditions, but also have abundant active binding sites for adsorption.
View Article and Find Full Text PDFGels
December 2024
Research Center for Green Energy Systems, Department of Mechanical Engineering, Gachon University, Seongnam-si 13120, Republic of Korea.
This study aims to develop efficient and sustainable hydrogels for dye adsorption, addressing the critical need for improved wastewater treatment methods. Carboxymethyl cellulose (CMC)-based hydrogels grafted with AAc were synthesized using gamma radiation polymerization. Various AAc to CMC ratios (5:5, 5:7.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, Tianjin 300457, China. Electronic address:
As an essential material for manufacturing lithium batteries, the demand of lithium is increasing, which means novel extracting method from various lithium-containing solutions is necessary. Spiropyran molecules undergo a photoisomerization reaction under light, transitioning from a closed-ring form (colorless) to an open-ring form (colored), generating multiple coordination sites to form coordination bonds with metal ions. In this paper, a polyacrylamide/carboxymethyl chitosan composite aerogel grafted with photoresponsive spiropyragroups (FeO/CNTs@PAM/CS-SP), used for extracting lithium from solutions, was prepared by dual cross-linking and vacuum freeze-drying.
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