- Simple process for the preparation of cetyltrimethylammonium naproxenate (naprocet)
-
Specifications for cetyltrimethylammonium (CTA) naproxenate (naprocet), the active ingredient of pharmaceutical liquid preparations used as antiseptic-antinflammatory detergents, fix severe limits to the presence of residual inorganic counteranion deriving from the starting CTA salt. A new simple procedure, which avoids ionic exchange chromatography and utilizes CTAHSO4 in place of CTABr and CTACl, exploits the quantitative precipitation of K2SO4 from methanol to yield naprocet in line with such specification requirements.
- Bolchi, Cristiano,Valoti, Ermanno,Fumagalli, Laura,Ruggeri, Paola,Straniero, Valentina,Pallavicini, Marco
-
-
Read Online
- Formation of a lanthanoid complex shell on a nanoparticulate wax core
-
Carboxylate-rich lanthanide complexes were employed as anion counterions to the cationic surfactant cethyltrimethylammonium (CTA) and assembled to form a shell around emulsifying wax nanoparticles. The anionic complexes consisted of lanthanide ions coordinated by the ligand DOTA-tetrahomoserine (DhS). In combination with CTA the complexes formed a surfactant system (CTA)[LnDhS] (Ln = Eu, Gd) with the nonpolar tail of CTA embedded in an emulsifying wax (EW) nanoparticle core. The DhS units were then crosslinked with divinylsulfone to form a shell around the EW core. Fluorescence and NMR data on the Eu complex were consistent with the formation of a stable polymeric shell around the wax core template. These results illustrate a general method that exploits electrostatic interactions to assemble capsules around solid lipid nanoparticles. Preliminary relaxivity measurements were carried out on particles with Gd-containing shells.
- Akturk, Eser,Kim, Joo-Hyung,Koppolu, Sujeethraj,Roth, Eric,Walters, Marc A.
-
-
Read Online
- Counter cation dependent and stimuli responsive supramolecular polymers constructed by calix[4]pyrrole based host–guest interactions
-
Carboxylate tethered calix[4]pyrroles in the form of their tetrabutylammonium (TBA) and cetyltrimethylammonium (CTA) salts were synthesized via an acid base reaction between the corresponding carboxylic acid functionalized calix[4]pyrrole and tetrabutyl-or cetyltrimethylammonium hydroxide. The host–guest recognition motif based on these calix[4]pyrrole macrocycles and tethered carboxylate units was employed to construct novel A–B type supramolecular polymers from low molecular weight monomers in chloroform. These supramolecular polymers were found to be dependent on the counter cation in terms of the properties of supramolecular polymers.1H-, DOSY-, NOESY-NMR spectroscopic analyses, viscosity measurements, and SEM results were used to characterize supramolecular polymers and revealed that the CTA cation becomes a direct part of supramolecular polymer via cation–π interactions between the ammonium part of CTA and carboxylate-bound calix[4]pyrrole, effecting the overall properties of supramolecular polymers such as viscosity, gel formation, and drawing fibers. Additionally, reversible pH-and thermo-responsiveness of the supramolecular polymers were demonstrated for the first time for an anion recognition induced calix[4]pyrrole based supramolecular polymer.
- Yuvayapan, Samet,Aydogan, Abdullah
-
-
Read Online
- Electron-Transfer Equilibria and Kinetics of N-Alkylphenothiazines in Micellar Systems
-
The kinetics and equilibria of electron transfer between N-alkylphenothiazines (alkyl = methyl, ethyl, butyl, dodecyl) and aquoiron (III)/(II) in the presence of various micellar forming surfactants (hexadecyltrimethylammonium methanesulfonate, sodium dodecylsulfate, and Triton X(100) were investigated.The presence of the micelles strongly affects rates and equilibria, and the dependence of these changes on the hydrophobicity of the alkyl chain is examined.
- Pelizetti, Ezio,Fisicaro, Emilia,Minero, Claudio,Sassi, Alberto,Hidaka, Hisao
-
-
Read Online
- Synthesis of two chiral surfactants by a simple method and the surface activity evaluation
-
In order to expand the application range of surfactants, two chiral surfactants named CTACYT and CTATYS were synthesized by reacting cetyltrimethylammonium chloride (CTAC) with L-cysteine and L-tyrosine, respectively by a simple method. Studies show that the foaming ability, foam stability and emulsifying properties of both CTACYT and CTATYS are superior to CTAC. The corrosion inhibition efficiencies of CTACYT and CTATYS are 96.72% and 90.22%, respectively, which are higher than that of CTAC. The new chiral surfactants remain the chiral character, and the specific optical rotations of CTACYT and CTATYS were 8.1° and 11.6°, respectively. This work provides a new and easy way to the synthesis of chiral surfactants, which will benefit the related research in this field.
- Bai, Yun,Chen, Gang,Dong, Sanbao,Liu, Dengwei,Qu, Chengtun,Yan, Jiao,Zhang, Jie,Zhu, Shidong
-
-
Read Online
- A new approach to the phase behavior of oppositely charged polymers and surfactants
-
The complex salt (ionic surfactant + polymeric counterion) cetyltrimethylammonium polyacrylate (CTAPA) has been synthesized, and its aqueous mixtures with cetyltrimethylammonium bromide (CTABr) have been studied. These mixtures differ from conventional oppositely charged polymer/surfactant mixtures in that the conventional counterion of the polyion (usually sodium, for the polyacrylate) is absent, which simplifies the studies and their interpretation considerably. The phase diagram of the CTAPA/CTABr/water system at > 20 wt % water and at 40 ?°C has been established, representing the first truly ternary phase diagram of an oppositely charged polymer/surfactant pair in water. The two dimensions of the phase diagram may be chosen as the water content (in weight percent) and the fraction of bromide counterions, xBr (in units of charge equivalents). The phase diagram is characterized by a large hexagonal phase (at low water contents and for all values of xBr), a small cubic phase (at 55 wt % water content and for xBr Br > 0.9), and a large multiphase region (at water contents >50 wt %) containing two or three of the cubic, hexagonal, or isotropic phases in coexistence. The cubic and hexagonal phases are connected to the corresponding phases that separate out from aqueous NaPA/CTABr mixtures. The maximum water uptake of the hexagonal phase is remarkably constant at ca. 50 wt % over a large CTAPA/CTABr composition range (xBr 0.9). The study confirms previous conclusions that the polyacrylate counterions favor a higher aggregate curvature (leading to smaller aggregates) than do the bromide counterions.
- Svensson, Anna,Piculell, Lennart,Cabane, Bernard,Ilekti, Philippe
-
-
Read Online
- Preparation of Acifluorfen-Based Ionic Liquids with Fluorescent Properties for Enhancing Biological Activities and Reducing the Risk to the Aquatic Environment
-
In this work, 12 novel herbicidal ionic liquids (HILs) based on acifluorfen were prepared by pairing with the fluorescent hydrazides or different alkyl chains for increasing activities and reducing negative impacts on the aquatic environment. The results showed that the fluorescence of coumarin hydrazide in the HILs was applied as the internal and supplementary light source to meet the requirement of light wavelength range of acifluorfen, which improved the phytotoxicity of acifluorfen to weeds by enhancing singlet oxygen generation with increased sunlight utilization. The herbicidal activities of HILs were related positively with the length of chain of cation under high light intensity and depended mainly on the fluorescence characteristic of the cation under low light intensity, and the double salt IL forms of acifluorfen containing coumarin hydrazide and n-hexadecyltrimethylammonium had enhanced efficacies against broadleaf weeds in the field. Compared with acifluorfen sodium, HILs had lower water solubility, better surface activity, weaker mobility in soils, and higher decomposition temperature. These results demonstrated that HILs containing different cations provided a wider scope for fine-tuning of the physicochemical and biological properties of herbicides and established a promising way for the development of environmentally friendly herbicidal formulations.
- Cao, Yongsong,Li, Jianqiang,Niu, Junfan,Tang, Gang,Tang, Jingyue,Tang, Rong,Yang, Jiale,Zhang, Wenbing,Zhou, Zhiyuan
-
p. 6048 - 6057
(2020/06/26)
-
- Highly efficient roomerature phosphorescence achieved by gadolinium complexes
-
A new family of room temperature phosphorescent materials with emission lifetimes in microseconds has been reported in this work. Phosphorescence of gadolinium complexes with emission color from blue to orange has been obtained at room temperature with a maximum photoluminescence quantum yield of 66%, benefiting from appropriate molecular structures and favorable encapsulation methods.
- Sun, Boxun,Wei, Chen,Wei, Huibo,Cai, Zelun,Liu, Huanyu,Zang, Zhiyu,Yan, Wenchao,Liu, Zhiwei,Bian, Zuqiang,Huang, Chunhui
-
supporting information
p. 14958 - 14961
(2019/10/22)
-
- Energy efficient Pfitzinger reaction: A novel strategy using a surfactant catalyst
-
A novel energy efficient method for the Pfitzinger reaction is demonstrated, which is catalysed using a surfactant, cetyltrimethylammonium hydroxide. The surfactant nature of the catalyst caused the substrate to be soluble in aqueous media, which enhanced the interaction of the catalyst with the substrate. An increase in the rate of reaction and more than 78% of energy saving were observed under ultrasonic irradiation.
- More, Priyanka A.,Shankarling, Ganapati S.
-
supporting information
p. 12380 - 12383
(2017/11/06)
-
- Quaternary ammonium salt type perrhenate ionic liquid and synthetic method and application thereof
-
The invention discloses quaternary ammonium salt type perrhenate ionic liquid and a synthetic method and application thereof. The method comprises the steps that alkyl ammonium bromide and KOH are reacted to obtain quaternary ammonium base, the quaternary ammonium base and perrhenate (NH4ReO4) metal salt are subjected to a replacement reaction, and quaternary ammonium salt type perrhenate ionic liquid is obtained. The synthesized quaternary ammonium salt type perrhenate ionic liquid is a pollution-free catalyst, has catalysis activity for lignocellulose, can be used as the catalyst for degrading lignocellulose to prepare reducing sugar, and the high yield is obtained.
- -
-
Paragraph 0026
(2017/06/02)
-
- Ammonium ionic liquids with anions of natural origin
-
This study was focused on presenting a new class of ionic liquids (ILs) with anions of natural origin. The salts were obtained by hydrolysis of defined triglycerides or edible vegetable oils (coconut oil and canola oil) by quaternary ammonium hydroxides. The basic physicochemical properties of the obtained products were studied and their microbial and deterrent activity was determined. Additionally, their susceptibility to biodegradation was evaluated. The described synthesis pathway utilizes vegetable oils and quaternary ammonium hydroxides as reactants in order to obtain ILs with anions of natural origin, which are characterized by specific biological activity. The majority of the prepared ILs exhibited excellent feeding deterrent properties and could be classified as readily biodegradable compounds. The employed method is characterized by low cost of substrates, high yields and high purity of the obtained products. It might potentially find application as a tool to synthesize environmentally friendly ILs with attractive properties for a wide range of applications.
- Pernak, Juliusz,Lgosz, Bartosz,Walkiewicz, Filip,Klejdysz, Tomasz,Borkowski, Andrzej,Chrzanowski, Lukasz
-
p. 65471 - 65480
(2015/08/18)
-
- Pickering emulsion stabilized by catalytic polyoxometalate nanoparticles: A new effective medium for oxidation reactions
-
Decyl-, dodecyl-, and tetradecyltrimethylammonium cations were combined with the catalytic polyoxometalate [PW12O40]3- anion to give spherical and monodisperse nanoparticles that are able to stabilize emulsions in the presence of water and an aromatic solvent. This triphasic liquid/solid/liquid system, based on a catalytic surfactant, is particularly efficient as a reaction medium for epoxidation reactions that involve hydrogen peroxide. The reactions proceed at competitive rates with straightforward separation of the phases by centrifugation. Such catalytic "Pickering" emulsions combine the advantages of heterogeneous catalysis and biphasic catalysis without the drawbacks (e.g., catalyst leaching or separation time). Mixing it up a bit: Spherical nanoparticles of decyl- and dodecyltrimethylammonium cations with [PW12O40] 3- formed stable Pickering emulsions in the presence of an aromatic solvent and water. This system is an efficient medium for epoxidation (see figure). Copyright
- Leclercq, Loic,Mouret, Adrien,Proust, Anna,Schmitt, Veronique,Bauduin, Pierre,Aubry, Jean-Marie,Nardello-Rataj, Veronique
-
supporting information
p. 14352 - 14358
(2013/01/15)
-
- The aqueous phase behavior of polyion-surfactant ion complex salts mixed with nonionic surfactants
-
The aim of this work was to study intermolecular interactions in systems containing charged polyion (polyacrylate, PA-), charged surfactant (C16TA+) and nonionic surfactant (C12E 5 or C12E8). To achieve this we have created four different phase diagrams using two different so-called complex salts, C16TAPA25 and C16TAPA6000, both consisting of positively charged surfactant (C16TA+) with polyacrylate (PA-) as counterions (no simple salt). The difference between the salts is the length of the polyion (25 or 6000 monomers). Both are insoluble in water. The results revealed that decreasing polyion length and increasing the PEO chain length of the nonionic surfactant were important factors for increasing the solubility of the complex salt. We also found that the curvature effects are quite small at low water content when gradually exchanging C12E8 for either one of the complex salts while there is a gradual change in curvature for the systems containing C 12E5. Another interesting observation was the possibility for relatively large amounts of complex salt to be incorporated into a V 1 (Ia3d, bicontinuous) phase in the C12E 8-containing systems. This gives rise to several questions regarding arrangements and dynamics of the polyion in this phase. In the dilute regime several different liquid crystalline phases can coexist with a dilute liquid phase containing the nonionic surfactant. the Owner Societies 2011.
- Janiak, John,Piculell, Lennart,Olofsson, Gerd,Schillen, Karin
-
experimental part
p. 3126 - 3138
(2011/09/20)
-
- Nitric oxide switches on the photoluminescence of molecularly engineered quantum dots
-
(Figure Presented) The photoluminescence of nonfluorescent molecularly engineered quantum dots (QDs) with iron(III) dithiocarbamates was selectively switched on by nitric oxide. Such functional QDs consisted of CdSe-ZnS nanocrystals as fluorophores and surface bound tris(N-(dithiocarboxy) sarcosine)iron(III) as reactive centers for nitric oxide. The fluorescence of the QDs was quenched by energy transfer between the excited QD cores and the surface bound iron(III) dithiocarbamates due to their optical energy overlapping. Nitric oxide restored the fluorescence of the QDs through reduction of the surface bound iron(III) complexes to iron(I) -NO adducts and thus shutting down the energy transfer pathway. The fluorescence of the iron(III) complex engineered QDs was selectively and quantitatively restored by nitric oxide but not by other reactive oxygen species. Such a property of the functional QDs could be used for sensing nitric oxide based on the fluorescence "turn on" mechanism.
- Wang, Suhua,Han, Ming-Yong,Huang, Dejian
-
supporting information; experimental part
p. 11692 - 11694
(2009/12/08)
-
- Synthesis and vesicle formation from hybrid bolaphile/ amphiphile ion-pairs. Evidence of membrane property modulation by molecular design
-
Four new hybrid (bolaphile/amphiphile) ion-pairs were synthesized. Electron microscopy indicated that each of these forms bilayer membranes upon dispersion in aqueous media. Membrane properties have also been examined by differential scanning calorimetry, microcalorimetry, temperature-dependent fluorescence anisotropy measurements, and UV-vis spectroscopy. The Tm values for the vesicular 1,2,3,4, and 5 were 38,12,85,31.3, and 41.6 °C, respectively. Interestingly the Tm values for 1 and 3 were found to depend on their concentration. The entrapment of small solute and the release capability have also been examined to demonstrate that these bilayers form enclosed vesicles. X-ray diffraction of the cast films has been performed to understand the nature and the thickness of these membrane organizations. The membrane widths ranged from 33 to 47 A. Finally, the above observations have been analyzed in light of the results obtained from molecular modeling studies. Thus we have demonstrated that membrane properties can be modulated by simple structural changes at the amphiphile level. It was shown that by judicious incorporation of central, isomeric, disubstituted aromatic units as structural anchors into different bolaphiles, one can modulate the properties of the resulting vesicles.
- Bhattacharya, Santanu,De Soma,Subramanian
-
p. 7640 - 7651
(2007/10/03)
-
- Modulation of vesicular properties by variation of shapes of bolaform counter ions in hybrid-ion paired surfactants
-
Four new vesicle-forming bolaphile/amphiphile ion pairs are synthesized; the bolaphile shapes in such hybrid systems strongly control their vesicular properties.
- Bhattacharya, Santanu,De, Soma
-
p. 1283 - 1284
(2007/10/03)
-
- Hydrogen transfer and isoparaffin-olefin alkylation process
-
The transfer of hydrogen from a paraffin to an olefin is provided. This reaction may be carried out in the presence of a catalyst, such as MCM-36. Especially when the paraffin reactant is an isoparaffin, the olefin produced from the reacted isoparaffin may react with unreacted isoparaffin to also produce an alkylate product.
- -
-
-
- Reactions in Micelles of Cetyltrimethylammonium Hydroxyde. Test of the Pseudophase Model for Kinetics
-
The rate constants for reactions of OH- with 2,4-dinitrochlorobenzene (DCNB), 2,4-dinitrochloronaphthalene (DNCN), and p-nitrophenyl diphenyl phosphate (pNPDPP) in micellized cetyltrimethylammonium hydroxyde (CTAOH) do not conform to the pseudophase ion-exchanged model.The rate constants do not become constant when substrates are fully micellar bound and increase on addition of NaOH.However, with the more hydrophobic substrates DNCN and pNPDPP we appear to reach limiting rate constants at high or high .These observations can be explained on the assumption that the charge on a CTAOH micelle decreases on addition of OH-, i.e., the concentration of OH- in the micelle increases with increasing -> in the aqueous pseudophase.The rate-surfactant profiles for reactions of DNCN and pNPDPP can be interpreted quantitatively in these terms.For reactions of DNCB the rate data can be interpreted if we assume that added OH- also increasees binding of DNCB to the micelle.
- Bunton, Clifford A.,Gan, Leong-Huat,Moffatt, John R.,Romsted, Laurence S.,Savelli, Gianfranco
-
p. 4118 - 4125
(2007/10/02)
-
