scholarly journals Rheological Properties of Hydrophobically Associative Copolymers Prepared in a Mixed Micellar Method Based on Methacryloxyethyl-dimethyl Cetyl Ammonium Chloride as Surfmer

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Rui Liu ◽  
WanFen Pu ◽  
Hu Jia ◽  
XiaoPei Shang ◽  
Yue Pan ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Ammonium Chloride ◽  
Mixed Micelles ◽  
Aggregation Number ◽  
Conductivity Measurement ◽  
Water Soluble ◽  
Experimental Conditions ◽  
Micellar Polymerization ◽  
Insight Into ◽  
Micelle System

A novel cationic surfmer, methacryloxyethyl-dimethyl cetyl ammonium chloride (DMDCC), is synthesized. The micellar properties, including critical micelle concentration and aggregation number, of DMDCC-SDS mixed micelle system are studied using conductivity measurement and a steady-state fluorescence technique. A series of water-soluble associative copolymers with acrylamide and DMDCC are prepared using the mixed micellar polymerization. Compared to conventional micellar polymerization, this new method could not only reasonably adjust the length of the hydrophobic microblock, that is,NH, but also sharply reduce the amount of surfactant. Their rheological properties related to hydrophobic microblock and stickers are studied by the combination of steady flow and linear viscoelasticity experiments. The results indicate that both the hydrophobic content and, especially the length of the hydrophobic microblock are the dominating factors effecting the intermolecular hydrophobic association. The presence of salt influences the dynamics of copolymers, resulting in the variation of solution characters. Viscosity measurement indicates that mixed micelles between the copolymer chain and SDS molecules serving as junction bridges for transitional network remarkably enhance the viscosity. Moreover, the microscopic structures of copolymers at different experimental conditions are conducted by ESEM. This method gives us an insight into the preparation of hydrophobically associative water-soluble copolymers by cationic surfmer-anionic surfactant mixed micellar polymerization with good performance.

Influence of hydrophobe fraction content on the rheological properties of hydrosoluble associative polymers obtained by micellar polymerization

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Enrique J. Jiménez-Regalado ◽  
Elva B. Hernández-Flores
Keyword(s):  
Relaxation Time ◽  
Rheological Properties ◽  
Polymer Concentration ◽  
Water Soluble ◽  
Polymer Chains ◽  
Associative Polymers ◽  
Hydrophobically Modified ◽  
Viscosity Increase ◽  
Increase Rate ◽  
Micellar Polymerization

AbstractThe synthesis, characterization and rheological properties in aqueous solutions of water-soluble associative polymers (AP’s) are reported. Polymer chains consisting of water-soluble polyacrylamides, hydrophobically modified with low amounts of N,N-dihexylacrylamide (1, 2, 3 and 4 mol%) were prepared via free radical micellar polymerization. The properties of these polymers, with respect to the concentration of hydrophobic groups, using steady-flow and oscillatory experiments were compared. An increase of relaxation time (TR) and modulus plateau (G0) was observed in all samples studied. Two different regimes can be clearly distinguished: a first unentangled regime where the viscosity increase rate strongly depends on hydrophobic content and a second entangled regime where the viscosity follows a scaling behavior of the polymer concentration with an exponent close to 4.

Molecularly Imprinted Sensor for Ascorbic Acid Based on Gold Nanoparticles and Multiwalled Carbon Nanotubes

2020 ◽  
Vol 16 (7) ◽  
pp. 905-913
Author(s):  
Youyuan Peng ◽  
Qingshan Miao
Keyword(s):  
Carbon Nanotubes ◽  
Gold Nanoparticles ◽  
Ascorbic Acid ◽  
Multiwalled Carbon Nanotubes ◽  
Ph Value ◽  
Biological Fluids ◽  
Water Soluble ◽  
Multiwalled Carbon ◽  
Experimental Conditions ◽  
Molecularly Imprinted

Background: L-Ascorbic acid (AA) is a kind of water soluble vitamin, which is mainly present in fruits, vegetables and biological fluids. As a low cost antioxidant and effective scavenger of free radicals, AA may help to prevent diseases such as cancer and Parkinson’s disease. Owing to its role in the biological metabolism, AA has also been utilized for the therapy of mental illness, common cold and for improving the immunity. Therefore, it is very necessary and urgent to develop a simple, rapid and selective strategy for the detection of AA in various samples. Methods: The molecularly imprinted poly(o-phenylenediamine) (PoPD) film was prepared for the analysis of L-ascorbic acid (AA) on gold nanoparticles (AuNPs) - multiwalled carbon nanotubes (MWCNTs) modified glass carbon electrode (GCE) by electropolymerization of o-phenylenediamine (oPD) and AA. Experimental parameters including pH value of running buffer and scan rates were optimized. Scanning electron microscope (SEM), fourier-transform infrared (FTIR) spectra, cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were utilized for the characterization of the imprinted polymer film. Results: Under the selected experimental conditions, the DPV peak currents of AA exhibit two distinct linear responses ranging from 0.01 to 2 μmol L-1 and 2 to 100 μmol L-1 towards the concentrations of AA, and the detection limit was 2 nmol L-1 (S/N=3). Conclusion: The proposed electrochemical sensor possesses excellent selectivity for AA, along with good reproducibility and stability. The results obtained from the analysis of AA in real samples demonstrated the applicability of the proposed sensor to practical analysis.

scholarly journals Methane and Inflammation - A Review (Fight Fire with Fire)

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Marietta Zita Poles ◽  
László Juhász ◽  
Mihály Boros
Keyword(s):  
Stress Responses ◽  
Nitrosative Stress ◽  
Ischemia Reperfusion ◽  
Signalling Pathways ◽  
Experimental Conditions ◽  
Neuroprotective Effects ◽  
Oxidative And Nitrosative Stress ◽  
Carbohydrate Fermentation ◽  
Insight Into

AbstractMammalian methanogenesis is regarded as an indicator of carbohydrate fermentation by anaerobic gastrointestinal flora. Once generated by microbes or released by a non-bacterial process, methane is generally considered to be biologically inactive. However, recent studies have provided evidence for methane bioactivity in various in vivo settings. The administration of methane either in gas form or solutions has been shown to have anti-inflammatory and neuroprotective effects in an array of experimental conditions, such as ischemia/reperfusion, endotoxemia and sepsis. It has also been demonstrated that exogenous methane influences the key regulatory mechanisms and cellular signalling pathways involved in oxidative and nitrosative stress responses. This review offers an insight into the latest findings on the multi-faceted organ protective activity of exogenous methane treatments with special emphasis on its versatile effects demonstrated in sepsis models.

scholarly journals Formation of complement subcomponent C1q-immunoglobulin G complex. Thermodynamic and chemical-modification studies

1982 ◽  
Vol 205 (2) ◽  
pp. 361-372 ◽  
Author(s):  
E J Emanuel ◽  
A D Brampton ◽  
D R Burton ◽  
R A Dwek
Keyword(s):  
Immunoglobulin G ◽  
Water Soluble ◽  
Small Peptide ◽  
Experimental Conditions ◽  
Salt Ions ◽  
Salt Range ◽  
Lysine Residues ◽  
Arginine Residues ◽  
Equilibrium Process ◽  
Glycine Ethyl Ester

The interaction between the complement subcomponent C1q and immunoglobulin G was investigated under a variety of experimental conditions. Formation of the subcomponent C1q-immunoglobulin G complex was shown to be an equilibrium process. Thermodynamic studies of the effect of varying the ionic strength indicate that over the salt range 0.15-0.225 M-NaCl the binding of subcomponent C1q to immunoglobulin aggregates releases 9-12 salt ions (Na+ and/or Cl-), illustrating the importance of ionic interactions for the formation of the complex. The effects of small peptide and organic ion inhibitors support this conclusion. Chemical modifications of carboxylate residues on immunoglobulin G by glycine ethyl ester/water-soluble carbodi-imide (up to 12 residues modified per whole molecule of immunoglobulin G) and of lysine residues by acetic anhydride (3 residues per whole molecule of immunoglobulin G) or methyl acetimidate (19 residues per whole molecule of immunoglobulin G) lowered the binding affinity of immunoglobulin for subcomponent C1q. Modification of arginine residues by cyclohexane-1,2-dione-1,2 (14 residues per whole molecule of immunoglobulin G) and of tryptophan by hydroxynitrobenzyl bromide (2 residues per whole molecule of immunoglobulin G), however, had little or no effect. The results are consistent with the proposal that the subcomponent-C1q-binding site on immunoglobulin G is to be found on the last two beta-strands of the Cv2 domain [Burton, Boyd, Brampton, Easterbrook-Smith, Emanuel, Novotny, Rademacher, van Schravendijk, Sternberg & Dwek (1980) Nature (London) 288, 338-344].

scholarly journals Technical and Economic Feasibility of a Stable Yellow Natural Colorant Production from Waste Lemon Peel

2020 ◽  
Author(s):  
Rosaria Ciriminna ◽  
Billy Forest ◽  
Francesco Meneguzzo ◽  
Mario Pagliaro ◽  
Mark Hamann
Keyword(s):  
Physical Stability ◽  
Economic Feasibility ◽  
Water Soluble ◽  
Hydrodynamic Cavitation ◽  
Natural Colorant ◽  
Lemon Peel ◽  
Citrus Flavonoids ◽  
Extraction Processes ◽  
Solid Liquid ◽  
Insight Into

A brief technical and economic insight into producing the water-soluble yellow colorant limocitrol 3-O-6”-[3-hydroxyl-3-methylglutaryl)])-β-D-glucopyranoside from waste lemon peel via simple solid-liquid extraction in aqueous ethanol or via hydrodynamic cavitation of waste lemon peel in water, shows that the biocolorant can be obtained at affordable cost. Coupled to the simplicity and sustainability of the extraction processes suggested, the high chemical and physical stability of this polymethoxylated flavanol and the health benefits of citrus flavonoids, support industrialization of this new bioeconomy production.

scholarly journals Altered acrylic acid concentrations in hard and soft corals exposed to deteriorating water conditions

FACETS ◽  
2017 ◽  
Vol 2 (1) ◽  
pp. 531-544 ◽  
Author(s):  
Lori S.H. Westmoreland ◽  
Jennifer N. Niemuth ◽  
Hanna S. Gracz ◽  
Michael K. Stoskopf
Keyword(s):  
Acrylic Acid ◽  
Marine Algae ◽  
Soft Coral ◽  
Resonance Spectroscopy ◽  
Additional Insight ◽  
Experimental Conditions ◽  
Animal Metabolism ◽  
Reef Decline ◽  
Reliable Marker ◽  
Insight Into

A reliable marker of early coral response to environmental stressors can help guide decision-making to mitigate global coral reef decline by detecting problems before the development of clinically observable disease. We document the accumulation of acrylic acid in two divergent coral taxa, stony small polyp coral ( Acropora sp.) and soft coral ( Lobophytum sp.), in response to deteriorating water quality characterized by moderately increased ammonia (0.25 ppm) and phosphate (0.15 ppm) concentrations and decreased calcium (360 ppm) concentration, using nuclear magnetic resonance spectroscopy (NMR)-based metabolomic techniques. Changes in acrylic acid concentration in polyp tissues free of zooxanthellae suggest that acrylic acid could be a product of animal metabolism and not exclusively a metabolic by-product of the osmolyte dimethylsulfoniopropionate (DMSP) in marine algae or bacteria. Our findings build on previously documented depletions of acrylic acid in wild coral potentially correlated to temperature stress and provide additional insight into approaches to further characterize the nature of the metabolic accumulation of acrylic acid under controlled experimental conditions.

scholarly journals Internalization and Transport of PEGylated Lipid-Based Mixed Micelles across Caco-2 Cells Mediated by Scavenger Receptor B1

Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2022
Author(s):  
Xiangjie Su ◽  
Mercedes Ramírez-Escudero ◽  
Feilong Sun ◽  
Joep B. van den Dikkenberg ◽  
Mies J. van Steenbergen ◽  
...  
Keyword(s):  
Vitamin K ◽  
Colloidal Stability ◽  
Mixed Micelles ◽  
Scavenger Receptor ◽  
Facs Analysis ◽  
Pegylated Nanoparticles ◽  
Confocal Fluorescence ◽  
Docking Calculations ◽  
Epithelium Cells ◽  
Insight Into

The aim of this study was to get insight into the internalization and transport of PEGylat-ed mixed micelles loaded by vitamin K, as mediated by Scavenger Receptor B1 (SR-B1) that is abundantly expressed by intestinal epithelium cells as well as by differentiated Caco-2 cells. Inhibition of SR-B1 reduced endocytosis and transport of vitamin-K-loaded 0%, 30% and 50% PEGylated mixed micelles and decreased colocalization of the micelles with SR-B1. Confocal fluorescence microscopy, fluorescence-activated cell sorting (FACS) analysis, and surface plasmon resonance (SPR) were used to study the interaction between the mixed micelles of different compositions (varying vitamin K loading and PEG content) and SR-B1. Interaction of PEGylated micelles was independent of the vitamin K content, indicating that the PEG shell prevented vitamin K exposure at the surface of the micelles and binding with the receptor and that the PEG took over the micelles’ ability to bind to the receptor. Molecular docking calculations corroborated the dual binding of both vita-min K and PEG with the binding domain of SR-B1. In conclusion, the improved colloidal stability of PEGylated mixed micelles did not compromise their cellular uptake and transport due to the affinity of PEG for SR-B1. SR-B1 is able to interact with PEGylated nanoparticles and mediates their subsequent internalization and transport.

Ultradeformable vesicles: concepts and applications relating to the delivery of skin cosmetics

2021 ◽  
Author(s):  
Andang Miatmoko ◽  
Qurrota Ayunin ◽  
Widji Soeratri
Keyword(s):  
Skin Aging ◽  
Water Soluble ◽  
In Vivo Studies ◽  
Active Ingredients ◽  
Self Confidence ◽  
Skin Delivery ◽  
Cosmetic Ingredients ◽  
Insight Into

Skin aging is a phenomenon resulting in reduced self-confidence, thus becoming a major factor in social determinants of health. The use of active cosmetic ingredients can help prevent skin aging. Transfersomes are well known to be capable of deeply penetrating the dermis. This scoping review provides an insight into transfersomes and their prospective use in anti-aging cosmetics. Numerous reports exist highlighting the successful skin delivery of therapeutic agents such as high-molecular-weight, poorly water soluble and poorly permeable active ingredients by means of transfersomes. Moreover, in vitro and in vivo studies have indicated that transfersomes increase the deposition, penetration and efficacy of active ingredients. However, the use of transfersomes in the delivery of active cosmetic ingredients is limited. Considering their similar physicochemical properties, transfersomes should possess considerable potential as a delivery system for anti-aging cosmetics.

Improving the rheological properties of water-based calcium bentonite drilling fluids using water-soluble polymers in high temperature applications

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jinliang Liu ◽  
Fengshan Zhou ◽  
Fengyi Deng ◽  
Hongxing Zhao ◽  
Zhongjin Wei ◽  
...  
Keyword(s):  
High Temperature ◽  
Rheological Properties ◽  
Apparent Viscosity ◽  
Drilling Fluid ◽  
Shear Thickening ◽  
Water Soluble ◽  
Drilling Fluids ◽  
Drilling Depth ◽  
Filtration Loss ◽  
Calcium Bentonite

Abstract Most of bentonite used in modern drilling engineering is physically and chemically modified calcium bentonite. However, with the increase of drilling depth, the bottom hole temperature may reach 180 °C, thus a large amount of calcium bentonite used in the drilling fluid will be unstable. This paper covers three kinds of calcium bentonite with poor rheological properties at high temperature, such as apparent viscosity is greater than 45 mPa·s or less than 10 mPa·s, API filtration loss is greater than 25 mL/30 min, which are diluted type, shear thickening type and low-shear type, these defects will make the rheological properties of drilling fluid worse. The difference is attributed to bentonite mineral composition, such as montmorillonite with good hydration expansion performance. By adding three kinds of heat-resistant water-soluble copolymers Na-HPAN (hydrolyzed polyacrylonitrile sodium), PAS (polycarboxylate salt) and SMP (sulfomethyl phenolic resin), the rheological properties of calcium bentonite drilling fluids can be significantly improved. For example, the addition of 0.1 wt% Na-HPAN and 0.1 wt% PAS increased the apparent viscosity of the XZJ calcium bentonite suspension from 4.5 to 19.5 mPa·s at 180 °C, and the filtration loss also decreased from 20.2 to 17.8 mL.

scholarly journals 5-Phenyl-10,15,20-Tris(4-sulfonatophenyl)porphyrin: Synthesis, Catalysis, and Structural Studies

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3363 ◽  
Author(s):  
Aitor Arlegui ◽  
Zoubir El-Hachemi ◽  
Joaquim Crusats ◽  
Albert Moyano
Keyword(s):  
Alder Reaction ◽  
Water Soluble ◽  
Experimental Conditions ◽  
One Pot ◽  
Force Microscopy ◽  
Diels Alder Reaction ◽  
Transmission Electron ◽  
Porphyrin Synthesis ◽  
The One ◽  
Water Soluble Porphyrin

A convenient protocol for the preparation of 5-phenyl-10,15,20-tris(4-sulfonatophenyl)porphyrin, a water-soluble porphyrin with unique aggregation properties, is described. The procedure relies on the one-pot reductive deamination of 5-(4-aminophenyl)-10,15,20-tris(4-sulfonatophenyl)porphyrin, that can be in turn easily obtained from 5,10,15,20-tetraphenylporphyrin by a known three-step sequence involving mononitration, nitro to amine reduction and sulfonation of the phenyl groups. This method provides the title porphyrin in gram scale, and compares very favorably with the up to now only described procedure based on the partial sulfonation of TPP, that involves a long and tedious chromatographic enrichment of the final compound. This has allowed us to study for the first time both the use of its zwitterionic aggregate as a supramolecular catalyst of the aqueous Diels–Alder reaction, and the morphology of the aggregates obtained under optimized experimental conditions by atomic force microscopy and also by transmission electron cryomicroscopy.

Sign in / Sign up

Export Citation Format

Share Document