Enhanced adsorption of anionic surfactants on negatively charged quartz sand grains treated with cationic polyelectrolyte complex nanoparticles

2018 ◽  
Vol 553 ◽  
pp. 397-405 ◽  
Author(s):  
Xilong Zhou ◽  
Jenn-Tai Liang ◽  
Corbin D. Andersen ◽  
Jiajia Cai ◽  
Ying-Ying Lin
Keyword(s):  
Quartz Sand ◽  
Polyelectrolyte Complex ◽  
Anionic Surfactants ◽  
Cationic Polyelectrolyte ◽  
Enhanced Adsorption

Improving Performance of Water-Reducing Admixtures by Modification of Quartz Sands with Electrolyte

2019 ◽  
Vol 945 ◽  
pp. 141-146
Author(s):  
S.M. Rakhimbayev ◽  
N.M. Tolypina ◽  
E.N. Khakhaleva
Keyword(s):  
Quartz Sand ◽  
Fine Particles ◽  
Anionic Surfactants ◽  
Concrete Mixture ◽  
High Concentration ◽  
Active Centers ◽  
Coarse Aggregates ◽  
Sand Surface ◽  
Quartz Sands ◽  
Positively Charged

It is widely known that modern anionic surfactants are adsorbed at positively charged active centers of hydrate phases in portland cement that leads to floccules decomposition as well as a release of immobilized water, therefore increasing cement paste flowability. Normally, in cement based concrete such fine and coarse aggregates as quartz sand, granite, sandstone etc. are used. They contain negatively charged active centers, therefore, are inert to anionic water-reducing admixture and don’t affect fluidization of cement based concrete mixture. For instance, quartz sand with high concentration of fine particles as well as oxides and hydroxides of Al and Fe cations demonstrates a higher reactivity to anionic water-reducing admixtures. In order to increase the efficiency of anionic surfactants in concrete mixtures the treatment of aggregates with salts based on two-and three-valent cations was proposed. That provides a higher concentration of positively charged active centers on quartz sand surface leading to increase of flowability of concrete mixture.

scholarly journals A salt-free, zero-discharge and dyebath-recyclable circular coloration technology based on cationic polyelectrolyte complex for cotton fabric dyeing

2021 ◽  
Author(s):  
Wen-Yi Wang ◽  
Jia-Chi Chiou ◽  
Wan-Xue Chen ◽  
Jia-Li Yu ◽  
Chi-wai Kan
Keyword(s):  
Textile Industry ◽  
Polyelectrolyte Complex ◽  
Cationic Polyelectrolyte ◽  
Cotton Fabrics ◽  
Acid Dyes ◽  
Anionic Dyes ◽  
Colour Measurements ◽  
Grade 3 ◽  
Dyed Fabrics ◽  
Dyed Fabric

Abstract Textile industry is one of the most polluting industries due to the large quantities of dyeing wastewater it generates and discharges. Herein, we report an eco-friendly and sustainable circular coloration technology based on cationic polyelectrolyte complex to realise salt-free, zero-effluent-discharge circular dyeing for cotton fabrics with a recyclable dyebath by using a typical cationic polyelectrolyte polyhexamethylene biguanide (PHMB) bonded with anionic dyes. The cotton fabrics were first treated with PHMB and then dyed with three commercial acid dyes. Colour measurements show that the colour strength is controllable by adjustment of concentrations of both PHMB and the dyebath. The dyed fabric samples were found to have good/excellent colour levelness (< 0.49), and the colour fastness (Grade 3 ~ 5) was basically satisfactory and acceptable. The dyebath was proved to be recyclable for circular dyeing occurring at room temperature, which greatly reduces consumption of both water and heat energy for textile dyeing. Meanwhile, the dyed fabrics showed antimicrobial activity, particularly for the gram-positive S. aureus, which may help reduce the healthcare-associated infections that transmit through textiles. These results suggest that cationic polyelectrolyte-based circular dyeing could provide a promising and practicable strategy to address the pollution issue caused by wastewater generated in dyeing process in the textile industry.

Phase behavior of cationic and anionic surfactants at low concentrations

1992 ◽  
Vol 50 (1) ◽  
pp. 694-695
Author(s):  
E. Naranjo
Keyword(s):  
Phase Behavior ◽  
Structural Characterization ◽  
Dynamic Systems ◽  
Anionic Surfactants ◽  
Intermolecular Forces ◽  
Stable Form ◽  
Surfactant Mixtures ◽  
Low Concentrations ◽  
Cationic And Anionic Surfactants ◽  
General Method

Equilibrium vesicles, those which are the stable form of aggregation and form spontaneously on mixing surfactant with water, have never been demonstrated in single component bilayers and only rarely in lipid or surfactant mixtures. Designing a simple and general method for producing spontaneous and stable vesicles depends on a better understanding of the thermodynamics of aggregation, the interplay of intermolecular forces in surfactants, and an efficient way of doing structural characterization in dynamic systems.

Direct Measurement of Charge Reversal on Lipid Bilayers using Heterodyne-Detected Second Harmonic Generation Spectroscopy

2019 ◽  
Author(s):  
HanByul Chang ◽  
Paul Ohno ◽  
Yangdongling Liu ◽  
Franz Geiger
Keyword(s):  
Lipid Bilayers ◽  
Surface Potential ◽  
Second Harmonic ◽  
Fluid Phase ◽  
Cationic Polyelectrolyte ◽  
Charge Reversal ◽  
Buried Interfaces ◽  
Phase Transition Temperatures ◽  
Complementary Techniques ◽  
Order Susceptibility

We report the detection of charge reversal induced by the adsorption of a cationic polyelectrolyte, poly(allylamine) hydrochloride (PAH), to buried supported lipid bilayers (SLBs), used as idealized model biological membranes. We observe changes in the surface potential in isolation from other contributors to the total SHG response by extracting the phase-shifted potential-dependent third-order susceptibility from the overall SHG signal. We demonstrate the utility of this technique in detecting both the sign of the surface potential and the point of charge reversal at buried interfaces without any prior information or complementary techniques<i>.</i>Furthermore, isolation of the second-order susceptibility contribution from the overall SHG response allows us to directly monitor changes in the Stern Layer. Finally, we characterize the Stern and Diffuse Layers over single-component SLBs formed from three different zwitterionic lipids of different gel-to-fluid phase transition temperatures (T<sub>m</sub>s). We determine whether the surface potential changes with the physical phase state (gel, transitioning, or fluid) of the SLB and incorporate 20 percent of negatively charged lipids to the zwitterionic SLB to investigate how the surface potential changes with surface charge.

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