We describe a new type of colloidal 2D gels formed in mixed Langmuir monolayers of stearic acid and octadecylamine on a surface of gold hydrosol. The adsorption of gold nanoparticles on the mixed monolayer led to an increase of interactions between oppositely charged surfactants giving a "soap" of mixed fatty salt. The observed effect is equivalent to a virtual "cooling" of floating monolayer, which undergoes rapid condensation on a surface of aqueous colloid. The consequent shrinking and rearrangement of the monolayer resulted in aggregation of nanoparticles into colloidal 2D "soap"-gels, which represented arrested colloidal phases within nonadsorbing organic medium. When sequentially deposited onto solids by Langmuir-Blodgett technique, the 2D "soap"-gels separated into organic and colloidal phases and gave dendrite-like bilateral organic crystallites coated with gold nanoparticles. The reported colloidal "soap"-assembly can offer a new opportunity to design 2D colloidal systems of widely variable chemistry and structures.
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http://dx.doi.org/10.1021/la202834n | DOI Listing |
Chemosphere
January 2025
Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, Salerno, Italy.
This research aims to design a novel selective and multifunctional adsorbent based on Al/Cu modified hemp fibres as a novel and multifunctional adsorbent for removing different classes of pollutants. The adsorbent, which was widely characterized, was shown to be more effective in removing anionic dyes compared to cationic ones. Among the tested dye, methyl orange was selected to understand how different parameters, such as temperature (20-80°C), contact time, pH (2-12), initial dye concentration (50-300 ppm), salinity and adsorbent dosage (1-10 g/L) affect the removal capacity.
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January 2025
Univ. Rouen Normandie, Normandie Univ., SMS, UR 3233, F-76000 Rouen, France.
It has been shown that depositing ketoprofen as thin films on glass substrates has a stabilizing effect on the amorphous state of ketoprofen. Polyethylene glycol ( = 6000 g/mol) was mixed with ketoprofen in a wide range of concentrations. Amorphous thin films were prepared by spin coating and subjected to storage conditions with different levels of relative humidity.
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December 2024
School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, P. R. China.
The dispersion of cellulose nanocrystals (CNCs) in suspensions determines the quality of the CNC-reinforced composites. Before being mixed into the composite matrix, stable suspensions must maintain a well-dispersed state, requiring proper design strategies to prevent agglomeration and precipitation. Considering the volume fraction, aspect ratio, and zeta potential, this paper proposes a coarse-grained model to simulate CNC clustering and an experimental program to observe accelerated precipitation of CNCs.
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December 2024
Department of Civil Engineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208016, India.
Widespread geogenic uranium (U) contamination of Indian groundwaters is of serious concern; yet little is known of the dominant forms and release mechanisms of U in these aquifers. Interestingly, manganese (Mn)-rich aquifers, highly buffered by dissolved inorganic carbon (DIC) and saturated with rhodochrosite [MnCO], have shown low U (
Langmuir
December 2024
School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an 710049, P. R. China.
This study explores the bubble nucleation process and heat transfer characteristics on nanostructured solid surfaces with mixed-wettable pillars using molecular dynamics simulations. Five different surfaces were designed by varying the wettability of the central pillars while keeping the lateral pillars hydrophilic. The nucleation behavior of argon bubbles was observed to differ significantly across these surfaces due to the combined effects of nanostructuring and mixed wettability.
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