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Atomic Force Microscopy and Molecular Dynamic Simulation of Adsorption of Polyacrylamide with Different Chemistries onto Calcium Carbonate.
Lew, Jin Hau; Hue, Keat Yung; Matar, Omar K; Müller, Erich A; Luckham, Paul F; Santos, Adrielle Sousa; Myo Thant, Maung Maung.
Afiliación
  • Lew JH; Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK.
  • Hue KY; Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK.
  • Matar OK; Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK.
  • Müller EA; Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK.
  • Luckham PF; Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK.
  • Santos AS; Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK.
  • Myo Thant MM; PETRONAS Research Sdn. Bhd., Lot 3288 & 3289, Off Jalan Ayer Itam, Kawasan Institusi Bangi, Kajang 43000, Selangor, Malaysia.
Polymers (Basel) ; 16(4)2024 Feb 10.
Article en En | MEDLINE | ID: mdl-38399872
ABSTRACT
This study investigates the interaction of polyacrylamide (PAM) of different functional groups (sulfonate vs. carboxylate) and charge density (30% hydrolysed vs. 10% hydrolysed) with calcium carbonate (CaCO3) via atomic force microscopy (AFM) and partly via molecular dynamic (MD) simulations. The PAM used were F3330 (30% hydrolysed), AN125 (25% sulfonated), and AN910 (% hydrolysed). A total of 100 ppm of PAMs was prepared in 0.1% NaCl, 3% NaCl, and 4.36% NaNO3 to be employed in AFM experiments, while oligomeric models (30 repeating units) of hydrolysed polyacrylamide (HPAM), sulfonated polyacrylamide (SPAM), and neutral PAM (NPAM) were studied on a model calcite surface on MD simulations. AFM analysis indicated that F3330 has a higher average adhesion and interaction energy with CaCO3 than AN125 due to the bulky sulfonate side group of AN125 interfering with SPAM adsorption. Steric repulsion of both PAMs was similar due to their comparable molecular weights and densities of the charged group. In contrast, AN910 showed lower average adhesion and interaction energy, along with slightly longer steric repulsion with calcite than F3330, suggesting AN910 adopts more loops and tails than the slightly flatter F3330 configuration. An increase in salt concentration from 0.1% to 3% NaCl saw a reduction in adhesion and interaction energy for F3330 and AN125 due to charge screening, while AN910 saw an increase, and these values increased further at 4.36% NaNO3. MD simulations revealed that the salt ions in the system formed salt bridges between PAM and calcite, indicating that the adhesion and interaction energy observed from AFM are likely to be the net balance between PAM charged group screening and salt bridging by the salt ions present. Salt ions with larger bare radii and smaller hydrated radii were shown to form stronger salt bridges.
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Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Idioma: En Revista: Polymers (Basel) Año: 2024 Tipo del documento: Article Pais de publicación: Suiza
Texto completo
Añadir a Mi BVS
Imprimir
XML
PubMed Links
Buscar en Google

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Idioma: En Revista: Polymers (Basel) Año: 2024 Tipo del documento: Article Pais de publicación: Suiza