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N-Acyl conjugates of amino acids, found in mammalian brain and other tissues, act as agonists and antagonists to receptors. In the present study, we synthesized and investigated the self-assembly, thermotropic phase transitions, and supramolecular organization of a homologous series of N-acyl-l-alanines (NAAs) containing saturated acyl chains (n=8–20). The critical micellar concentrations (CMCs) of...
The hydrogen-bonded thin film of poly(vinylpyrrolidone) (PVPON)/poly(acrylic acid) (PAA) was prepared via layer-by-layer (LbL) assembly. A serial of solvents has been selected to study the formation and disintegration of the thin film. The film could be produced in acidic water and alcohols but could not be fabricated in some polar aprotic solvents, such as dimethylacetamide (DMA), dimethylsulfoxide...
Aggregation behavior of polyoxyethylene (POE)-type nonionic surfactant Tween 20 in imidazolium ionic liquids with varying chain length and different anions, such as tetrafluoroborate, hexafluorophosphate, bis(trifluoromethanesulfonyl)imide, and trifluoromethanesulfonate, was investigated by means of surface tension, conductivity and dynamic light scattering measurements. The role of the chain length,...
Casein-based emulsion for film former was innovatively prepared via emulsifier-free emulsion polymerization by employing self-made amphiphilic copolymers (A m B n C o ) as the stabilizer. Structure of A m B n C o was confirmed by 1 H NMR spectrometry. Stability of the as-prepared emulsion in different concentrations of A m B n ...
Ureasiloxane–polyethylene oxide 1900 hybrids loaded with CeO 2 nanoparticles were prepared by the sol–gel method, and the effects of CeO 2 incorporation on the structural and optical features of the hybrids were studied. The formation of a colloidal suspension of CeO 2 nanoparticles, prepared by the sol–gel process, was monitored in situ by UV–vis spectroscopy. After separation...
Alginate-based nanoparticles were generated by mixing two types of stock solutions through a microfluidic device. In our microfluidic mixing device, aqueous Ca-alginate pre-gels and cationic poly-l-lysine (PLL) solutions were mixed, and the polyelectrolyte complexation that subsequently occurred between the pre-gel and PLL resulted in precipitates, yielding alginate nanoparticles. Due to the faster...
A method for the fabrication of carbon–tethered Sn micro/nano composite spheres, a facile one-pot hydrothermal route followed by heat treatment in N 2 , is described. Heating of an aqueous solution of SnCl 4 and resorcinol–formaldehyde (RF) to 85°C for about 3h in a 50mL Teflon-lined stainless steel autoclave obtained the SnO 2 encapsulated RF composite polymer spheres. Subsequent...
Although foam has been widely used in petroleum industry, its instability is still a problem during its applications. Here, partially hydrophobic modified SiO 2 nanoparticles were used with sodium dodecyl sulfate (SDS) to increase the foam stability. Surface tension, interfacial dilational viscoelasticity, and ζ potential of SiO 2 /SDS aqueous dispersion had been determined and correlated...
The wetting behavior, adsorption amount and Zeta potential of aqueous solutions of the octadearyl dimethyl ammonium chloride (OTAC), cetyl trimethyl ammonium chloride (CTAC) and benzyl hexadecyl dimethyl ammonium chloride (HDBAC) on coal pitch surface were investigated. When the content of surfactant was constant, along with the growing of slurry concentration, the apparent viscosity of coal pitch...
Silicon carbide (SiC) foam prepared by polymer pyrolysis combined with molten silicon reactive infiltration (MRI) process was experimentally studied for the first time regarding its underwater acoustic absorption coefficient (α) mainly over low and middle frequency range (200–4000Hz). The relationship between α and the pore structure of SiC foam including pore size (d) and foam thickness (t) was studied...
In this paper, thermo responsive ZnO/PNIPAM nanocomposites were fabricated via electrospinning with the dispersing of ZnO nanoparticles into PNIPAM nanofibers. The effect of the electrospinning parameters on morphology of the nanofibers and the temperatures on the morphology of the nanocomposites was both investigated by SEM–EDS. Furthermore, the photocatalytic kinetics of the nanocomposites was studied...
Bile acids play an important role in fat digestion by displacing surfactants from the oil–water interface through emulsification. In this paper, we study the time course of the displacement of sodium dodecyl sulfate (SDS) from the liquid crystal (LC)/aqueous interface by four unconjugated bile acids, which differ in the number and position of hydroxyl groups on their steroid backbones. The competitive...
Aphrons are surfactant stabilized microbubbles with thick soapy shells. Stability is a key feature of microbubbles. Colloidal gas aphrons (CGAs), with an average diameter of 50μm, offer particular advantages where the stability of microbubbles is of interest. Various factors that affect on CGA stability such as surfactant type, concentration, and processing parameters have been extensively studied...
In this work the expansion of natural muscovite has been made through the treatments of calcination and ion exchange. The experimental results have demonstrated that the gallery of muscovite could be expanded from 0.32nm to 2.25nm with the treatments. The calcination was to weaken the bond or attraction of the layers to interlamellar K + and to move slightly the O atoms in dehydroxylation...
23 Na, 35 Cl, 81 Br, and 87 Rb NMR have been applied to clarify the influence of electrostatic and hydrophobic interactions on the counterion binding equilibria of weakly acidic and basic polyelectrolytes with negatively and positively charged polyions, respectively. Na + and Rb + ions capable of binding to weakly acidic polymers (i.e., polyacrylate acid...
Some dispersions of clay and silica particles in water in the presence of relatively high molecular weight polyethyleneoxide (PEO), which are fluid when at rest, become solid-like after a quick shake to such an extent that they can be held in the hand. On leaving the dispersions for a certain period of time, minutes to days depending on the polymer molecular weight and concentration, the dispersions...
The gradual increase of antibiotics in aquatic environments poses a serious threat to human health and ecosystems, and removal technology for antibiotics has attracted great interest in recent years. In this study, to improve the adsorption capacity of mesoporous silica, a new sorbent made by grafting both amino groups and Fe (III) on mesoporous silica SBA15 (named Fe-N,N-SBA15) was prepared and used...
Grazing incidence energy-dispersive X-ray diffraction (GID) studies of Langmuir–Blodgett (LB) films have been performed to study the role of substrate in controlling structural transformation in LB films. Thirteen monolayered LB film of cadmium arachidate (CdA) were deposited on two different chemically treated (OH and H terminated) Si(100) substrates. In both the CdA-H and CdA-OH LB multilayers,...
Nanocapsules (≤200nm) with a protection effect toward small hydrophobic guests (p-nitrophenyl laurate and acetylsalicylic acid, aspirin) and a tunable sustained release behavior have been fabricated through the layer-by-layer deposition of polyacrylic acid and modified chitosan. Cationic surfactant, cetyltrimethylammonium bromide, was used to increase the affinity of polyelectrolyte to the substrate...
Rates of flocculation of PSL particles induced by the addition of cationic polyelectrolyte of high charge density in the mixing flow near isoelectric point were measured as a function of ionic strength. Homopolymer of dimethylamino ethylmethacrylate with charge density of 100% and nominal molecular weight of 4900k (hereafter called TMAEMA) was used as a flocculant. Except just after the very short...
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