The adsorption of stereoregular polymers and its effect on the conformation and dynamics of the polymer at interfaces are only poorly understood. 1H NMR has revealed a lowering of the peaks assigned to isotactic sequences whatever the PMMA tacticity, which provides evidence of stereospecific adsorption of the isotactic segments on silica. Entropic factors are therefore assumed to control the configuration of the adsorbed layer. Tacticity-dependent rheological behavior is revealed by dynamic investigations carried out on silica dispersions. The driving forces likely to induce the stereoselective adsorption and tacticity-dependent rheology of suspensions are discussed.
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http://dx.doi.org/10.1016/j.jcis.2003.12.017 | DOI Listing |
Chem Rev
December 2024
Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, and State Key Laboratory of Molecular Engineering of Polymers, iChEM, Fudan University, Shanghai 200433, P. R. China.
Core-shell magnetic particles consisting of magnetic core and functional shells have aroused widespread attention in multidisciplinary fields spanning chemistry, materials science, physics, biomedicine, and bioengineering due to their distinctive magnetic properties, tunable interface features, and elaborately designed compositions. In recent decades, various surface engineering strategies have been developed to endow them desired properties (e.g.
View Article and Find Full Text PDFJ Adv Res
December 2024
Longping Branch, College of Biology, Hunan University, Changsha 410125, China; Yuelushan Laboratory, Changsha 410082, China; Key Laboratory of Pesticide Assessment, Ministry of Agriculture and Rural Affairs, Hunan Academy of Agricultural Sciences, Changsha 410125, China. Electronic address:
Introduction: Conventional pesticide formulations have been widely used to boost agricultural productivity, but their weak foliar adhesion and instability under UV light during spraying lead to low utilization rates and potential environmental and health hazards. To counter these challenges, the development of nanoformulations represents a pivotal strategy. These advanced formulations are designed to enhance the efficacy of active ingredients (AIs) and reduce ecological impacts, thereby addressing the need for sustainable agricultural development.
View Article and Find Full Text PDFACS Omega
December 2024
Department of Petroleum Engineering, King Fahd University of Petroleum & Minerals, Dhahran 34464, Saudi Arabia.
In chemical-enhanced oil recovery (cEOR), surfactants are widely used but face significant stability challenges in high-salinity brine, where they often degrade or precipitate. Existing methods, such as adding cosurfactants, offer limited compatibility with anionic surfactants and raise economic concerns, creating a need for more robust solutions. This study introduces a novel approach to enhance the stability of anionic surfactants in extreme salinity conditions by incorporating silicon dioxide (SiO) nanoparticles (NPs).
View Article and Find Full Text PDFJ Phys Chem B
December 2024
Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States.
The achievement of sufficient dispersion of vulcanization accelerators is critical to tailoring superior cross-linked elastomers. Modern recipes rely on multicomponent formulations with silica particles covered by coupling agents. We study the molecular properties of select accelerators in polyisoprene melts and their affinity for functionalized surfaces via extensive all-atom molecular dynamics simulations.
View Article and Find Full Text PDFPurpose: This study aims to compare the surface roughness (SR), contact angle (CA), surface free energy (SFE), and bacterial adhesion of resin-based materials used in additive, subtractive, and conventional manufacturing techniques.
Materials And Methods: This study involved four groups of 23 specimens: Indirect conventional resin composite (ICRC), subtractively manufactured resin composite (SMRC), additively manufactured resin composite (AMRC), and soda-lime-silica glass (SLSG). One specimen per group was analyzed by Energy Dispersive X-ray Spectroscopy (EDS) before polishing.
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