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https://www.readbyqxmd.com/read/28930637/sodium-hypochlorite-and-sodium-bromide-individualized-and-stabilized-carbon-nanotubes-in-water
#1
Xuezhu Xu, Jian Zhou, Veronica Colombo, Yangyang Xin, Ran Tao, Gilles Lubineau
Aggregation is a major problem for hydrophobic carbon nanomaterials such as carbon nanotubes (CNTs) in water because it reduces the effective particle concentrations, prevents particles from entering the medium and leads to unstable electronic device performances when a colloidal solution is used. Molecular ligands such as surfactants can help the particles to disperse, but they tend to degrade the electrical properties of CNTs. Therefore, self-dispersed particles without the need for surfactant are highly desirable...
September 20, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28930461/effect-of-a-swelling-agent-on-the-performance-of-ni-porous-silica-catalyst-for-ch4-co2-reforming
#2
Mohamad Hassan Amin, Putla Sudarsanam, Matthew R Field, Jim Patel, Suresh K Bhargava
Hierarchical porous materials are of great interest in various industrial applications because of their potential to overcome the mass transport limitations typically encountered for single-mode porous materials. This report describes the synthesis of a hierarchical tri-modal porous silica-based material using a 7.5 molar ratio of a relatively inexpensive non-ionic surfactant template, tri-block copolymer P123, EO20PO70EO20. The pore size distribution curve shows the presence of three types of pores with average diameters of ~8, 25 and 89 nm...
September 20, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28930353/interplay-between-bulk-self-assembly-interfacial-and-foaming-properties-in-a-catanionic-surfactant-mixture-of-varying-composition
#3
José Ferreira, Alesya Mikhailovskaya, Alexis Chenneviere, Frédéric Restagno, Fabrice Cousin, François Muller, Jéril Degrouard, Anniina Salonen, Eduardo F Marques
The self-aggregation, surface properties and foamability of the catanionic surfactant mixture cetyltrimethylammonium bromide (CTAB)/sodium octyl sulfonate (SOSo) have been investigated to obtain insight on the relation between bulk nanostructures, surfactant packing, and foam stability and aging. Light microscopy, SANS, cryo-TEM, DLS, surface tension, rheometry and direct photography were used to characterize mixtures with varying CTAB molar fraction, xCTAB. In the bulk, self-assembly is richer in the excess CTAB region than in the excess SOSo one...
September 20, 2017: Soft Matter
https://www.readbyqxmd.com/read/28930346/one-pot-solution-synthesis-of-shape-controlled-copper-selenide-nanostructures-and-their-potential-applications-in-photocatalysis-and-photothermal-therapy
#4
Xianwen Wang, Zhaohua Miao, Yan Ma, Huajian Chen, Haisheng Qian, Zhengbao Zha
Developing a facile and reliable method for the fabrication of transition metal chalcogenides is a vital and endless pursuit of scientific and technological disciplines. In this work, we develop a one-pot solution approach to obtain copper selenide nanostructures with different morphologies and crystal structures (Cu2Se nanoparticles, CuSe nanoplates and CuSe2 nanosheets). In comparison to previously reported methods, our method did not use expensive and very toxic raw materials. After detailed studies of reaction conditions, including temperature, reaction time, and feeding amount of surfactants and precursors, we found that the feeding ratio of precursors played a key role in the crystal structures and morphologies of the final products...
September 20, 2017: Nanoscale
https://www.readbyqxmd.com/read/28929199/sophorolipid-production-by-yeasts-a-critical-review-of-the-literature-and-suggestions-for-future-research
#5
REVIEW
Silke Claus, Inge N A Van Bogaert
Sophorolipids are well-known biosurfactants produced by yeasts, having potential applications ranging from nanomaterials, medicine, and cosmetics to large-volume applications such as cleaning and soil remediation. Because of their environmentally friendly nature, they attained much interest during the past decades as a sustainable and ecological alternative to petroleum-derived surfactants. Stronger yet, research activities and scientific publications on the topic are ever increasing. However, often these studies lack proper producer strain identification and detailed structural product characterization...
September 19, 2017: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/28929143/enhanced-stability-and-water-solubilizing-capacity-of-water-in-oil-microemulsions-based-on-protic-ionic-liquids
#6
Akhil Pratap Singh, Kaushik Kundu, Vikram Singh, Ramesh L Gardas, Sanjib Senapati
In an attempt to increase the stability and water uptake capacity of water-in-oil (W/O) microemulsions, here we study the physicochemical behavior of a series of protic ionic liquid based water/oil microemulsions, wherein solute amounts of biocompatible tetramethylguanidinium cation-based ionic liquids (ILs) are added to the aqueous phase of water-in-oil (W/O) microemulsions. FTIR and time-resolved fluorescence measurements showed an increased water uptake in these reverse micellar droplets, compared to conventional W/O microemulsions of similar compositions...
September 20, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28929103/authorization-and-toxicity-of-veterinary-drugs-and-plant-protection-products-residues-of-the-active-ingredients-in-food-and-feed-and-toxicity-problems-related-to-adjuvants
#7
REVIEW
Szandra Klátyik, Péter Bohus, Béla Darvas, András Székács
Chemical substances applied in animal husbandry or veterinary medicine and in crop protection represent substantial environmental loads, and their residues occur in food and feed products. Product approval is governed differently in these two sectors in the European Union (EU), and the occurrence of veterinary drug (VD) and pesticide residues indicated by contamination notification cases in the Rapid Alert System for Food and Feed of the EU also show characteristic differences. While the initial high numbers of VD residues reported in 2002 were successfully suppressed to less than 100 cases annually by 2006 and on, the number of notification cases for pesticide residues showed a gradual increase from a low (approximately 50 cases annually) initial level until 2005 to more than 250 cases annually after 2009, with a halt occurring only in 2016...
2017: Frontiers in Veterinary Science
https://www.readbyqxmd.com/read/28928527/lipase-catalyzed-transesterification-of-ethyl-butyrate-synthesis-in-n-hexane-a-kinetic-study
#8
N Annapurna Devi, G B Radhika, R J Bhargavi
Kinetics of lipase catalyzed transesterification of ethyl caprate and butyric acid was investigated. The objective of this work was to propose a reaction mechanism and develop a rate equation for the synthesis of ethyl butyrate by transesterification using surfactant coated lipase from Candida rugosa. The reaction rate could be described in terms of Michaelis-Menten equation with a Ping-Pong Bi-Bi mechanism and competitive inhibition by both the substrates. The values of kinetic parameters computed were Vmax = 2...
August 2017: Journal of Food Science and Technology
https://www.readbyqxmd.com/read/28927888/the-effect-of-water-hardness-on-surfactant-deposition-following-washing-and-subsequent-skin-irritation-in-atopic-dermatitis-patients-and-healthy-controls
#9
Simon G Danby, Kirsty Brown, Andrew M Wigley, John Chittock, Phyoe K Pyae, Carsten Flohr, Michael J Cork
Living in a hard water area is associated with an increased risk of atopic dermatitis (AD). Greater skin barrier impairment following exposure to surfactants in wash products combined with high calcium, and/or chlorine, levels in hard water is a compelling mechanism for this increase. The purpose of this study was to investigate this mechanism in individuals with and without a predisposition to skin barrier impairment. We recruited 80 subjects; healthy controls and AD patients with and without FLG mutations...
September 12, 2017: Journal of Investigative Dermatology
https://www.readbyqxmd.com/read/28926703/effect-of-non-ionic-surfactants-on-dispersion-and-polar-interactions-in-the-adsorption-of-cellulases-onto-lignin
#10
Feng Jiang, Chen Qian, Alan R Esker, Maren Roman
Residual lignin in pretreated biomass impedes enzymatic hydrolysis. Non-ionic surfactants are known to enhance the enzymatic hydrolysis of lignocellulosic biomass but their mechanisms of action are incompletely understood. This study investigates the effect of a non-ionic surfactant, Tween 80, on the adsorption of cellulases onto model lignin substrates. Lignin substrates were prepared by spin coating of flat substrates with three different types of lignin: organosolv lignin, kraft lignin, and milled wood lignin...
September 19, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28926341/maternal-plasma-lpcat-1-mrna-correlates-with-lamellar-body-count
#11
Robert A Welch, Maurice-Andre Recanati, Kathryn C Welch, Michael K Shaw
Human lysophosphatidylcholine acyltransferase 1 (hLPCAT1) is a protein which helps produce surfactant in the fetal lung. We previously reported that levels of cell-free fetal mRNA for hLPCAT1 in amniotic fluid are correlated with lamellar body count (LBC) (r2=0.93). This short communication demonstrates that fetal hLPCAT1 mRNA is also present in maternal blood. Its quantity also correlates with amniotic fluid LBC (r2=0.81). Research in maternal plasma hLPCAT1 may assist in understanding fetal and placental maturational processes...
September 19, 2017: Journal of Perinatal Medicine
https://www.readbyqxmd.com/read/28926254/new-in-situ-measurements-of-the-viscosity-of-gas-clathrate-hydrate-slurries-formed-from-model-water-in-oil-emulsions
#12
Ahmad Majid, David T Wu, Carolyn A Koh
In-situ rheological measurements for clathrate hydrate slurries were performed using a high pressure rheometer to determine the effect of hydrate particles on the viscosity and transportability of these slurries. These measurements were conducted using a well-characterized model water-in-oil emulsion1. The emulsion consists of a model liquid hydrocarbon, water, and a surfactant mixture of sorbitane monooleate 80 (Span 80) and sodium di-2-ethylhexylsulfosuccinate (Aerosol OT, AOT). This emulsion was used as an analog to water-in-crude oil (w/o) emulsions and provides reproducible results...
September 19, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28926252/absolute-enantiomeric-excess-determination-of-carbon-nanotubes-ensemble-by-symmetry-breaking-using-optical-titration-method
#13
Jinsook Sim, Somin Kim, Myungsu Jang, Minsuk Park, Hyunkyu Oh, Sang-Yong Ju
Symmetry breaking of single-walled carbon nanotubes (SWNTs) has profound effects on their optoelectronic properties which are essential for fundamental study and applications. Here, we show that isomeric SWNT which exhibit identical photoluminescence (PL) undergo symmetry breaking by flavin mononucleotide (FMN) and exhibits dual PLs and different binding affinity (Ka). Increasing FMN concentration leads to systematic PL shifts of SWNT according to structural modality and handedness due to symmetry breaking...
September 19, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28925972/improving-the-efficiency-of-new-automatic-dishwashing-detergent-formulation-by-addition-of-thermostable-lipase-protease-and-amylase
#14
Ashwini Naganthran, Malihe Masomian, Raja Noor Zaliha Raja Abd Rahman, Mohd Shukuri Mohamad Ali, Hisham Mohd Nooh
The use of T1 lipase in automatic dishwashing detergent (ADD) is well established, but efficiency in hard water is very low. A new enzymatic environmentally-friendly dishwashing was formulated to be efficient in both soft and hard water. Thermostable enzymes such as T1 lipase from Geobacillus strain T1, Rand protease from Bacillussubtilis strain Rand, and Maltogenic amylase from Geobacillus sp. SK70 were produced and evaluated for an automatic dishwashing detergent formulation. The components of the new ADD were optimized for compatibility with these three enzymes...
September 19, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28925888/a-self-nanoemulsifying-drug-delivery-system-for-poorly-water-soluble-tolbutamide-development-optimization-and-pharmacodynamic-studies
#15
Deepti Pandita, Neelam Kumari, Viney Lather
The current investigation involves the development of a thermodynamically stable and dilutable self-nanoemulsifying drug delivery system (SNEDDS) for tolbutamide, a poorly water soluble hypoglycemic drug, in order to achieve higher water solubility and enhanced dissolution rate which in turn improves its oral bioavailability. Pseudo-ternary phase diagrams suggested the suitability of oleic acid (lipid), Tween 20 (surfactant) and PEG 400 (co-surfactant) for developing the SNEEDS formulations. The optimal SNEDDS formulation having mean globule diameter, viscosity, polydispersity value of 58...
September 15, 2017: Pharmaceutical Nanotechnology
https://www.readbyqxmd.com/read/28925874/preclinical-assessment-of-steroidal-nanostructured-lipid-carriers-based-gels-for-atopic-dermatitis-optimization-and-product-development
#16
Upendra Nagaich, Neha Gulati
BACKGROUND: Betamethasone Valerate (BV) is potent topical corticosteroid. Preparation of nanostructured lipid carreirs (NLC) involves process parameters optimization and formulations were developed. It is available in several conventional formulations like creams and ointments which have well-known problems of frequent dosing and consequently additional side effects. The aim is to ascertain the probability of NLC as an exclusive carrier for betamethasone valerate topical application with regard to release modulation and improved therapeutic effect...
September 18, 2017: Current Drug Delivery
https://www.readbyqxmd.com/read/28925711/role-of-counterion-in-the-adsorption-behavior-of-1-1-ionic-surfactants-at-fluid-interfaces-adsorption-properties-of-alkali-perfluoro-n-octanoates-at-the-air-water-interface
#17
Klaus Lunkenheimer, Katrina Geggel, Dietrich Prescher
Equilibrium surface tension (σe) versus bulk concentration (c) isotherms of aqueous, surface-chemically pure solutions of various alkali perfluoro-n-octanoates were measured at 295 K. These 1:1 ionic surfactant systems belong to the pseudo nonionic ones. Evaluating the different σe vs log c isotherms by basic adsorption equations reveals that they follow ideal surface behavior. The novelty of this investigation exists in the fact that the surface area demand per molecule adsorbed calculated from the experimental σe vs log c isotherms is identical to that of the hydrated alkali cation...
September 19, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28925686/a-naphthalimide-based-fluorophore-for-soft-anionic-interface-monitoring
#18
Li Wang, Gang Wang, Congdi Shang, Rui Kang, Yu Fang
A naphthalimide-based low-molecular mass fluorophore (NA) was designed and synthesized by introducing an azetidine unit onto the aromatic ring of the compound as an electron-donating structure, and a hydrophilic (2-(2-aminoethylamino)ethanol) moiety into the 'N-imide site' of the core structure. UV-vis absorption and fluorescence measurements revealed that the fluorophore is soluble in water, and shows a fluorescent quantum yield of ~20% and lifetime of ~3.7 ns in the solvent within a wide pH range. Moreover, the fluorescence emission and anisotropy of the fluorophore as produced are both dependent upon the viscosity and polarity of the medium...
September 19, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28924739/purification-of-drug-loaded-plga-nanoparticles-prepared-by-emulsification-solvent-evaporation-using-stirred-cell-ultrafiltration-technique
#19
Suresh K Paswan, T R Saini
PURPOSE: The emulsifiers in an exceedingly higher level are used in the preparation of drug loaded polymeric nanoparticles prepared by emulsification solvent evaporation method. This creates great problem to the formulator due to their serious toxicities when it is to be administered by parenteral route. The final product is therefore required to be freed from the used surfactants by the conventional purification techniques which is a cumbersome job. METHODS: The solvent resistant stirred cell ultrafiltration unit (Millipore) was used in this study using polyethersulfone ultrafiltration membrane (Biomax®) having pore size of NMWL 300 KDa as the membrane filter...
September 18, 2017: Pharmaceutical Research
https://www.readbyqxmd.com/read/28924083/characterization-of-o-w-emulsions-prepared-by-peg-diisostearate-amphiphilic-random-copolymer
#20
Megumi Kaji, Sari Fujiwara, Kenichi Sakai, Hideki Sakai
We have characterized an emulsion system stabilized by an amphiphilic random copolymer, methoxy polyethylene glycol-23 methacrylate/glyceryl diisostearate methacrylate copolymer (MPM-GDM). The combined results of the static surface tension and transmission electron microscopy with freeze-fracture technique (FF-TEM) suggested that this copolymer forms aggregates in aqueous solutions. The membrane emulsification method produced an oil-in-water (O/W) emulsion in the mixture of squalane, water, and MPM-GDM, where the squalane concentration was set at 10 - 60 wt% and the MPM-GDM concentration was either 1 or 5 wt%...
September 15, 2017: Journal of Oleo Science
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