Acid‐Labile Amphiphilic PEO‐b‐PPO‐b‐PEO Copolymers: Degradable Poloxamer Analogs

Macromolecular Rapid Communications, Год журнала: 2016, Номер 37(9), С. 775 - 780

Опубликована: Март 22, 2016

Poly ((ethylene oxide)-b-(propylene oxide)-b-(ethylene oxide)) triblock copolymers commonly known as poloxamers or Pluronics constitute an important class of nonionic, biocompatible surfactants. Here, a method is reported to incorporate two acid-labile acetal moieties in the backbone generate acid-cleavable nonionic Poly(propylene oxide) functionalized by means acetate-protected vinyl ether introduce units. Three cleavable PEO-PPO-PEO (Mn,total = 6600, 8000, 9150 g·mol(-1) ; Mn,PEO 2200, 3600, 4750 ) have been synthesized using anionic ring-opening polymerization. The amphiphilic exhibit narrow molecular weight distributions (Ð 1.06-1.08). Surface tension measurements reveal surface-active behavior aqueous solution comparable established noncleavable poloxamers. Complete hydrolysis labile junctions after acidic treatment verified size exclusion chromatography. block employed surfactants miniemulsion polymerization polystyrene (PS) nanoparticles with mean diameters ≈200 nm and distribution, determined dynamic light scattering scanning electron microscopy. Acid-triggered precipitation facilitates removal surfactant fragments from nanoparticles, which simplifies purification enables nanoparticle "on demand."

Язык: Английский

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Surfactant-free microemulsions with cleavable constituents

Journal of Molecular Liquids, Год журнала: 2018, Номер 271, С. 112 - 117

Опубликована: Авг. 24, 2018

Язык: Английский

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Effect of imidazolium-based ionic liquids on the aggregation behavior of twin-tailed cationic gemini surfactant in aqueous solution

Journal of Dispersion Science and Technology, Год журнала: 2016, Номер 38(3), С. 393 - 402

Опубликована: Апрель 5, 2016

Micellization behavior of the twin-tailed surfactants can be modulated by addition various modifiers. Ionic liquids (ILs) are one them and documented here. The beauty these environmentally benign neoteric molecules lies in their structural versatility. Here, we have investigated effect three ILs: 1-butyl-3-methylimidazolium bromide ([C4mim][Br]), 1-hexyl-3-methylimidazolium ([C6mim][Br]), 1-octyl-3-methylimidazolium ([C8mim][Br]) on aggregation surface adsorption cationic gemini surfactant, bis(hexadecyldimethyl ammonium)propane dibromide (16-3-16) through experimentally measured electrical conductivities, tensions, spectral methods (UV-vis absorbance fluorescence measurements). main focus study is to observe added ILs critical micelle concentration (cmc), parameters, number, size aggregates surfactant. results show that more hydrophobic ILs, is, [C6mim][Br] [C8mim][Br] behave as electrolyte at lower cosurfactant higher concentration, whereas moderately IL [C4mim][Br] acts an all ranges studied. modulating effects were also compared with conventional (NaBr) similar conditions.

Язык: Английский

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Cleavable Surfactants: A Comparison between Ester, Amide, and Carbonate as the Weak Bond

Journal of Surfactants and Detergents, Год журнала: 2019, Номер 22(5), С. 1139 - 1145

Опубликована: Фев. 7, 2019

Abstract Cleavable surfactants, i.e., surfactants in which a weak bond has deliberately been inserted into the molecule, are of interest when remaining surface‐active material at surface can cause problems. Ester and amide bonds established as week linkages but these generate an acid they hydrolyze. For some applications, acidic degradation products unwanted. Surfactants with carbonate between polar headgroup hydrophobic tail for such purposes. In this article, we compare physical–chemical properties nonionic those corresponding ester surfactants. The half‐lives different cleavable also compared it was found that is slightly more stable to alkaline hydrolysis than present otherwise identical structures. A Gemini surfactant spacer, on decomposes two single‐tailed amphiphiles, presented. kinetics studied detail degrades much faster low temperature higher temperature. This anti‐Arrhenius type proposed be due reverse solubility versus behavior ethoxylated

Язык: Английский

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Volatile short-chain amphiphiles derived from isosorbide: Hydrotropic properties of esters vs. ethers

RSC Advances, Год журнала: 2013, Номер 3(17), С. 5997 - 5997

Опубликована: Янв. 1, 2013

Two series of short-chain isosorbide monoalkanoates, differing from the free hydroxyl position, were synthesized and evaluated as volatile non-ionic hydrotropes, also known "solvo-surfactants". Their aqueous solubilities, solubilizing efficiencies volatilities compared to corresponding 5-O-alkylisosorbides. Whatever acylation position (5-O- or 2-O-), monoalkanoates are poorly water-soluble for acyl chains longer than four carbons, whereas 5-O-alkylisosorbides completely miscible with water up a pentyl chain, which seems indicate that an ether link brings more hydrophilicity ester bond these types molecules. The shorter butanoates particularly efficient in terms solubilization hydrophobic compounds. In addition, all hydrotropes exhibit some volatility albeit being non-VOC contrarily their ethers homologues, alkanoates easily hydrolysed basic medium, suggests good biodegradability.

Язык: Английский

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Spontaneous Formation of Nanocubic Particles and Spherical Vesicles in Catanionic Mixtures of Ester-Containing Gemini Surfactants and Sodium Dodecyl Sulfate in the Presence of Electrolyte

The Journal of Physical Chemistry B, Год журнала: 2014, Номер 118(11), С. 3063 - 3073

Опубликована: Фев. 18, 2014

Self-assembly of pure ester-containing cationic gemini surfactants, dodecyl esterquat, and betainate geminis, cation-rich catanionic mixtures them with sodium sulfate (SDS) were investigated using surface tension, electrical conductivity, dynamic light scattering (DLS), transmission electron microscopy (TEM) cyclic voltammetry (CV) measurements in the absence presence KCl. Different physicochemical properties such as critical micelle concentration (CMC), degree counterion dissociation (αdiss), interfacial properties, morphology aggregates, interparticle interaction parameters determined. Both geminis formed micelles KCl, mixing SDS did not change morphology; just a growth size was observed. However, aggregation behavior these respect to position ester bond alkyl chain appeared completely different Esterquat cubic nanoparticles (or cobosomes) [KCl] = 0.05 M transformed into spherical upon increasing surfactant concentration. By contrast, vesicles subsequently converted increased. The esterquat (in KCl) after changed from cylindrical coexistent cobosomes. Betainate remained vesicular SDS, no dramatic structural aggregates took place. changes explained calculating interactions between two surfactants on basis regular solution theory.

Язык: Английский

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A reverse degradation vs. temperature relationship for a carbonate-containing gemini surfactant

Journal of Colloid and Interface Science, Год журнала: 2018, Номер 531, С. 189 - 193

Опубликована: Июль 19, 2018

Язык: Английский

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Micellar Effects on the Hydrolysis Reaction of an Anionic Surfactant in Aqueous Solution

Langmuir, Год журнала: 2018, Номер 34(46), С. 13979 - 13992

Опубликована: Ноя. 9, 2018

The hydrolysis mechanisms of 2-sulfoalkanoic acid methyl ester salts (methyl sulfonate, MES) were studied. Under acidic, neutral, and alkaline conditions, the rates MES strongly affected by state aggregation rate changed at critical micelle concentration (CMC). acidic enhanced micellar formation correlated quantitatively with amount protons bound on surfaces being measured electric conductivity along fluorescence hydrogen-ion electrode measurements. having longer acyl chain lengths showed higher above CMC because many degree counterion binding to micelle, β. type followed order sodium > potassium calcium MES. In suppressed lower values CMC. Additionally, under neutral conditions a very low value formation. These inhibitory effect should be dominated electrical repulsive interactions between hydroxyl anions anionic surfaces, as well interference penetration anion group in micelles for from water molecules hydrolysis.

Язык: Английский

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Synthesis, surface activity and antielectrostatic properties of new soft dichain cationic surfactants

Colloids and Surfaces A Physicochemical and Engineering Aspects, Год журнала: 2015, Номер 480, С. 63 - 70

Опубликована: Янв. 29, 2015

Язык: Английский

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The roles of betaine-ester analogues of 1-N-alkyl-3-N′-methyl imidazolium salts: as amphotropic ionic liquid crystals and organogelators

RSC Advances, Год журнала: 2013, Номер 3(47), С. 25151 - 25151

Опубликована: Янв. 1, 2013

Betaine-ester analogues of 1-N-alkyl-3-N′-methyl imidazolium salts exhibiting both thermotropic and lyotropic liquid crystal behaviors are reported. Two typical compounds, structurally determined by single X-ray diffraction exhibit an interdigitated bilayer packing. These compounds gelators, which form gels in a variety organic solvents such as chloroform, methanol, ethanol, tetrahydrofuran, while also lamellar mesophase. Results from IR variable-temperature 1H NMR spectroscopy studies show that trace amount water (0.3–0.5% volume) CHCl3 plays crucial role for developing the H-bonded network during gel formation. Ag-NPs (∼5–10 nm size) obtained LC solution different morphologies ranging spherical to truncated triangular plates.

Язык: Английский

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