Study on Interaction of Carboxylic Acid Gemini Surfactant with Cocamidopropyl Betaine in Aqueous Solution

2021 ◽  
Vol 58 (3) ◽  
pp. 204-210
Author(s):  
Ruijuan Wang ◽  
Ying Qin ◽  
Shuo Yang ◽  
Dong Wang ◽  
Zhigang Yin
Keyword(s):  
Surface Tension ◽  
Carboxylic Acid ◽  
Gemini Surfactant ◽  
Aggregate Size ◽  
Molar Ratio ◽  
Ph Titration ◽  
Cryogenic Transmission Electron Microscopy ◽  
Zwitterionic Form ◽  
Transmission Electron ◽  
Cocamidopropyl Betaine

Abstract The interaction of carboxylic acid gemini surfactant 4,8-didodecyl-3,9-dioxo-6-hydroxy-4,8-diaza-1,11-undecanedicarboxylic acid (CGS12) with amphoteric surfactant cocamidopropyl betaine (CAPB) at 258C and pH 7.0 has been investigated using pH titration, surface tension, dynamic light scattering (DLS) and cryogenic transmission electron microscopy (Cryo-TEM) measurements. The pH titration results show that CGS12 exhibits anionic surfactant properties and CAPB exists as a zwitterionic form at pH 7.0. The surface tension results show that the critical micelle concentration (CMC) values of the CAPB/CGS12 mixture are low, and basically exhibit a decreasing trend with decreasing molar ratio of CAPB (XCAPB). The variation of the CMC of the mixture reveals that the mixing is close to ideal. The DLS results indicate that the CAPB/ CGS12 mixture mainly forms the larger aggregates with the hydrate radii approximately 70-145 nm at various XCAPB. The Cryo-TEM images further demonstrate the CAPB/CGS12 mixtures mainly form vesicles. The results indicate that the aggregate size and microstructure of the mixture change little with the variation of XCAPB.

scholarly journals Hydrothermally Assisted Fabrication of TiO2-Fe3O4 Composite Materials and Their Antibacterial Activity

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4715
Author(s):  
Adam Kubiak ◽  
Marta Kubacka ◽  
Elżbieta Gabała ◽  
Anna Dobrowolska ◽  
Karol Synoradzki ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Composite Materials ◽  
Bet Surface Area ◽  
Molar Ratio ◽  
Oxide Content ◽  
Gram Positive ◽  
Gram Negative ◽  
Transmission Electron ◽  
Xrd Patterns ◽  
Oxide Composites

The TiO2-Fe3O4 composite materials were fabricated via the hydrothermal-assisted technique. It was determined how the molar ratio of TiO2 to Fe3O4 influences the crystalline structure and morphology of the synthesized composite materials. The effect of the molar ratio of components on the antibacterial activity was also analyzed. On the basis of XRD patterns for the obtained titanium(IV) oxide-iron(II, III) oxide composites, the two separate crystalline forms—anatase and magnetite —were observed. Transmission electron microscopy revealed particles of cubic and tetragonal shape for TiO2 and spherical for Fe3O4. The results of low-temperature nitrogen sorption analysis indicated that an increase in the iron(II, III) oxide content leads to a decrease in the BET surface area. Moreover, the superparamagnetic properties of titanium(IV) oxide-iron(II, III) oxide composites should be noted. An important aim of the work was to determine the antibacterial activity of selected TiO2-Fe3O4 materials. For this purpose, two representative strains of bacteria, the Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, were used. The titanium(IV) oxide-iron(II, III) oxide composites demonstrated a large zone of growth inhibition for both Gram-positive and Gram-negative bacteria. Moreover, it was found that the analyzed materials can be reused as antibacterial agents in three consecutive cycles with good results.

scholarly journals Probing the Na metal solid electrolyte interphase via cryo-transmission electron microscopy

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Bing Han ◽  
Yucheng Zou ◽  
Zhen Zhang ◽  
Xuming Yang ◽  
Xiaobo Shi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solid Electrolyte ◽  
Solid Electrolyte Interphase ◽  
Metal Electrode ◽  
Liquid Electrolyte ◽  
Battery Materials ◽  
Cryogenic Transmission Electron Microscopy ◽  
Transmission Electron ◽  
Fluoroethylene Carbonate

AbstractCryogenic transmission electron microscopy (cryo-TEM) is a valuable tool recently proposed to investigate battery electrodes. Despite being employed for Li-based battery materials, cryo-TEM measurements for Na-based electrochemical energy storage systems are not commonly reported. In particular, elucidating the chemical and morphological behavior of the Na-metal electrode in contact with a non-aqueous liquid electrolyte solution could provide useful insights that may lead to a better understanding of metal cells during operation. Here, using cryo-TEM, we investigate the effect of fluoroethylene carbonate (FEC) additive on the solid electrolyte interphase (SEI) structure of a Na-metal electrode. Without FEC, the NaPF6-containing carbonate-based electrolyte reacts with the metal electrode to produce an unstable SEI, rich in Na2CO3 and Na3PO4, which constantly consumes the sodium reservoir of the cell during cycling. When FEC is used, the Na-metal electrode forms a multilayer SEI structure comprising an outer NaF-rich amorphous phase and an inner Na3PO4 phase. This layered structure stabilizes the SEI and prevents further reactions between the electrolyte and the Na metal.

scholarly journals Alpha helical surfactant-like peptides self-assemble into pH-dependent nanostructures

Soft Matter ◽  
2021 ◽  
Vol 17 (11) ◽  
pp. 3096-3104
Author(s):  
Valeria Castelletto ◽  
Jani Seitsonen ◽  
Janne Ruokolainen ◽  
Ian W. Hamley
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Small Angle ◽  
Self Assembly ◽  
X Ray ◽  
Cryogenic Transmission Electron Microscopy ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Ph Dependent ◽  
Ray Scattering

A designed surfactant-like peptide is shown, using a combination of cryogenic-transmission electron microscopy and small-angle X-ray scattering, to have remarkable pH-dependent self-assembly properties.

Low-temperature route to nanoscale P3N5 hollow spheres

2003 ◽  
Vol 18 (10) ◽  
pp. 2359-2363 ◽  
Author(s):  
Hongzhou Gu ◽  
Yunle Gu ◽  
Zhefeng Li ◽  
Yongcheng Ying ◽  
Yitai Qian
Keyword(s):  
Photoelectron Spectroscopy ◽  
Hollow Spheres ◽  
Molar Ratio ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Influence Of Temperature On ◽  
Wide Gap ◽  
20 Nm ◽  
High Degree

Nanoscale hollow spheres of amorphous phosphorus nitride (P3N5) were synthesized by reacting PCl3 with NaN3 at 150–250 °C. Transmission electron microscope images show that the hollow spheres have a diameter of 150–350 nm, and the thickness of the shell is 20 nm. A very small amount of curly films were also found in the sample prepared at 150 °C. The infrared spectrum indicates a high degree of purity. X-ray photoelectron spectroscopy indicates the presence of P and N, with a molar ratio of 1:1.62 for P:N. Ultraviolet-visible absorption spectroscopy shows an absorption band at 265–315 nm. Under photoluminescent excitation at 230 nm, the P3N5 emits ultraviolet light at 305 nm. With a band gap of 4.28 eV, the products may be a wide gap semiconductor. A possible mechanism and the influence of temperature on the formation of the hollow spheres are also discussed.

scholarly journals Clozapine-carboxylic acid plasticized co-amorphous dispersions: Preparation, characterization and solution stability evaluation

2015 ◽  
Vol 65 (2) ◽  
pp. 133-146 ◽  
Author(s):  
Ahmed Mahmoud Abdelhaleem Ali ◽  
Adel Ahmed Ali ◽  
Ibrahim Abdullah Maghrabi
Keyword(s):  
Carboxylic Acid ◽  
Tartaric Acid ◽  
Molar Ratio ◽  
Sublingual Administration ◽  
Solution Stability ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Great Chance ◽  
Amorphous Dispersions ◽  
Pass Metabolism

Abstract This study addressed the possibility of forming of co-amorphous systems between clozapine (CZ) and various carboxylic acid plasticizers (CAPs). The aim was to improve the solubility and oral bioavailability of clozapine. Co-amorphous dispersions were prepared using modified solvent evaporation methodology at drug/plasticizer stoichiometric ratios of 1:1, 1:1.5 and 1:2. Solid state characterization was performed using differential scanning calorimetry, X-ray diffraction and infra red spectroscopy. Highly soluble homogeneous co-amorphous dispersions were formed between clozapine and CAPs via hydrogen bonding. The co-amorphous dispersions formed with tartaric acid (1:2) showed the highest dissolution percentage (> 95 % in 20 minutes) compared to pure crystalline CZ (56 %). Highly stable solutions were obtained from co-amorphous CZ-citric and CZ-tartaric acid at 1:1.5 molar ratio. The prepared dispersions suggest the possibility of peroral or sublingual administration of highly soluble clozapine at a reduced dose with the great chance to bypass the first pass metabolism.

Development of intravaginal rod insert bearing liposomal raloxifene hydrochloride and Leuprolide acetate as a potential carrier for uterine targeting

2021 ◽  
Author(s):  
Arpita Patel ◽  
Rahul Dhande ◽  
Hetal Thakkar
Keyword(s):  
Entrapment Efficiency ◽  
Leuprolide Acetate ◽  
Liposomal Formulation ◽  
Molar Ratio ◽  
White Female ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Intravaginal Administration ◽  
Raloxifene Hydrochloride ◽  
Dual Drug

Abstract Objectives This project aimed at the formulation of dual drug entrapped liposomes held as freeze-dried intravaginal rod insert (IVR), to be administered by vaginal route for uterine targeting. Methods Liposomes were formulated by dehydration–rehydration method using 3 : 1 molar ratio of1,2-distearoyl-sn-glycero-3-phosphocholine : Cholesterol. Characterization was done for vesicle size, zeta potential, entrapment efficiency, surface morphology and % loading. Key findings Spherical and discrete vesicles of size 354 nm were observed in transmission electron microscopy (TEM) image. The entrapment efficiency of 90.91% and 74.3% w/w was obtained for Raloxifene Hydrochloride (RLX) and Leuprolide acetate (LA) respectively. Drug release was sustained for 6 days. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay results showed that dual drug entrapped liposomal formulation show significant cytotoxicity, as also confirmed by higher apoptosis in cell cycle analysis and apoptosis studies (FACS) analysis. Pharmacodynamic studies in New Zealand white female rabbits revealed that intravaginal administration of RLX-LA entrapped liposomal formulation shows considerable fibroid regression. Conclusions Uterine targeting of liposomal RLX-LA suggests its potential to solve the limitations of the presently available therapeutic options.

Immobilization of K7PW11O39 on ZrO2 Nanofiber: Ultra-deep Desulfurization Based in Extraction Catalytic Oxidation Desulfurization System

2021 ◽  
Vol 72 (3) ◽  
pp. 89-101
Author(s):  
Guowei Zeng ◽  
Guihong Wu ◽  
Zhihui Wang ◽  
Xiaonan Li ◽  
Jie Yang ◽  
...  
Keyword(s):  
Catalytic Oxidation ◽  
Catalytic Mechanism ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Thermo Gravimetric ◽  
Transmission Electron ◽  
Deep Desulfurization ◽  
Thermo Gravimetric Analyzer ◽  
Ft Ir ◽  
Model Oil

In this work, K7PW11O39 (abbreviated as PW11) was immobilized on ZrO2 nanofibers and used as an efficient recyclable catalyst in extraction catalytic oxidation desulfurization system (ECODS).The 500 ppm DBT model oil(5mL) can desulphurize completely within 20 min with the catalytic conditions of 50��, 0.010 g 50 wt%- CTAB�C PW11�CZrO2 nanofibers and O/S molar ratio H2O2/DBT molar ratio�� was 2:1. The synthesized catalyst was characterized by Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and thermo gravimetric analyzer (TGA). The results indicated the PW11�CZrO2 nanofibers were synthesized successfully and the possible catalytic mechanism is also revealed.

Vanadium Pentoxide Gels: Structural Development and Rheological Properties

1990 ◽  
Vol 180 ◽  
Author(s):  
J.K. Bailey ◽  
T. Nagase ◽  
G.A. Pozarnsky ◽  
M.L. Mecartney
Keyword(s):  
Vanadium Pentoxide ◽  
Structural Development ◽  
Small Particles ◽  
Rheological Characterization ◽  
Cryogenic Transmission Electron Microscopy ◽  
Transmission Electron ◽  
Before And After ◽  
Constant Shear Stress ◽  
Steady Shearing ◽  
Rheological Experiments

ABSTRACTCryogenic transmission electron Microscopy (cryo-TEM) and rheological characterization were conducted in order to understand structural development of vanadium pentoxide gels during processing. Sols were prepared by ion exchange from sodium metavanadate solutions. Cryo-TEM revealed that fine threads about 1.5nm wide initially form and grow into ribbons approximately 25nm wide and at least 1000nm long. The threads appear to self assemble into the ribbons. During this structural development, the dynamic viscosity increased. Upon steady shearing of the sols, the system exhibited thixotropy, i.e. the viscosity decreased with time under constant shear stress and subsequently rheopexy, the viscosity increased with time. Comparison of the structure before and after shearing indicated that during the rheological experiments aggregation of small particles or fragments was occurring.

Surface Activity Research of Cationic Gemini Surfactants

2013 ◽  
Vol 690-693 ◽  
pp. 2076-2080
Author(s):  
Zhen Zhong Fan ◽  
Lan Lan Li ◽  
Li Feng Zhang ◽  
Qing Wang Liu
Keyword(s):  
Surface Tension ◽  
Critical Micelle Concentration ◽  
Surface Activity ◽  
Surfactant Concentration ◽  
Gemini Surfactant ◽  
Gemini Surfactants ◽  
Ph Value ◽  
Inorganic Salts ◽  
Cationic Gemini Surfactant ◽  
Cationic Gemini Surfactants

Cationic Gemini surfactant concentration, the inorganic salts added and the pH value of surface tension obtained cationic gemini surfactant critical micelle concentration is 0.4mmol / L;by adding three kinds of inorganic salts NaCl, MgCl2, and Na2SO4 ,which Na2SO4 has the greatest impact on surface tension, followed by MgCl2.The surface minimum tension of the pH ranged from 9 to 11 , indicating that the surface activity of cationic gemini surfactants achieved the highest.

Sign in / Sign up

Export Citation Format

Share Document