Functional chitosan surfactants for corrosion inhibition in petroleum industry.

Chitosan is a natural biodegradable biopolymer, and the structure of its unit is 2-amino-d-glucopyranose that has been it more attractive to applied as natural corrosion inhibitor of metals for different area. Functionalization chitosan by surfactant is necessary to improve some of its properties such as solubility, surface activity, and corrosion inhibition efficiency. Corrosion of metals is a global problem particularly in petroleum industry field needs to favorably inhibition process using environmentally friendly inhibitors such chitosan.

Synthesis of anionic chitosan surfactant and application in silver nanoparticles preparation and corrosion inhibition of steel.

Three anionic chitosan surfactant with different hydrophobic tails labeled Chitosan-R8, Chitosan-R12 and Chitosan-R16 were prepared and their surface behavior in aqueous solution was determined by surface tension measurements at three different temperatures 20, 40 and 60 °C. The affinity of the synthesized anionic chitosan surfactant to form micelle enhanced with increasing the hydrophobic chain length as well as raising the solution temperature up to 60 °C. The anionic chitosan surfactant showed a great influence as capping agent for the in-situ preparation of silver nanoparticles (AgNPs) based on photochemical reduction method using sunlight as reducing agent.

Advancement on modification of chitosan biopolymer and its potential applications.

Chitosan is the second abundant biopolymer present on earth after cellulose. Chitosan is extracted from the shells of shrimp and other crustaceans. Several methods were reported for its extraction, but the most commercial is the deacetylation of chitin.

Adsorption of aluminum and lead from wastewater by chitosan-tannic acid modified biopolymers: Isotherms, kinetics, thermodynamics and process mechanism.

Chitosan was reacted by tannic acid to obtain three modified chitosan biopolymer. Their chemical structures were characterized by FTIR and elemental analysis. The prepared biopolymers were used to adsorb Al(III) and Pb(II) metal ions from industrial wastewater.

Remediation of distilleries wastewater using chitosan immobilized Bentonite and Bentonite based organoclays.

Organic-inorganic nanocomposite, namely chitosan immobilized Bentonite (CIB) with chitosan content of 5% was synthesized in an acetic acid solution (2%). Organically modified CIB and Bentonite (mbent.) were prepared by intercalating cetyl trimethylammonium bromide (CTAB) as a cationic surfactant at doses equivalent to 1.

Synthesis, characterization and anticorrosion potentials of chitosan-g-PEG assembled on silver nanoparticles.

Chitosan (Ch) grafted with poly(ethylene glycol) (Ch-g-mPEG) were synthesized using mPEG with molecular weights 2000 g/mol. The synthesized Ch-g-mPEG was characterized using gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H NMR), and X-ray diffraction (XRD) techniques. Ch-g-mPEG silver nanoparticles has been synthesized and characterized by high-resolution transmission electron microscopy (HRTEM) and energy dispersive analysis of X-rays (EDAX).

Synthesis and antimicrobial activity of polysaccharide alginate derived cationic surfactant-metal(II) complexes.

New natural polysaccharide carbohydrate derivatives of sodium alginate surfactant and its cobalt, copper and zinc complexes were synthesized. Structures of the synthesized compounds are reported using FTIR, (1)H NMR and UV-vis. The critical micelle concentration (CMC) value of the alginate surfactant and its metal complexes in aqueous solution was found out from surface tension measurements.

Metal adsorption by agricultural biosorbents: Adsorption isotherm, kinetic and biosorbents chemical structures.

Biosorption of Cu(II), Co(II) and Fe(III) ions from aqueous solutions by rice husk, palm leaf and water hyacinth was investigated as a function of initial pH, initial heavy metal ions concentration and treatment time. The adsorption process was examined by two adsorption isotherms: Langmuir and Freundlich isotherms. The experimental data of biosorption process were analyzed using pseudo-first order, pseudo-second order kinetic models.

Preparation of Some Eco-friendly Corrosion Inhibitors Having Antibacterial Activity from Sea Food Waste.

Chitosan is one of the important biopolymers and it is extracted from exoskeletons of crustaceans in sea food waste. It is a suitable eco-friendly carbon steel corrosion inhibitor in acid media; the deacetylation degree of prepared chitosan is more than 85.16 %, and the molecular weight average is 109 kDa.

Prevalence and antimicrobial resistance pattern of multidrug-resistant enterococci isolated from clinical specimens.

Purpose: Vancomycin-resistant enterococci (VRE) pose an emerging problem in hospitals worldwide. The present study was undertaken to determine the occurrence, species prevalence, antibacterial resistance, and phenotypic and genetic characteristics of VRE isolated in Riyadh hospitals, KSA.

Materials And Methods: Two hundred and six isolates of enterococcal species were obtained from clinical samples.

Microbial contamination of cosmetics and personal care items in Egypt--body lotions and talcum powders.

We examined a total of 54 samples, including 18 body lotions and 36 talcum powders, for their total aerobic bacterial, coliform and fungal counts. We also carried out anaerobic bacterial counts for talcum powder as well as tests to detect some potentially hazardous bacteria in all tested samples. Talcum powders were more heavily contaminated with bacteria and fungi than body lotions.

Microbial contamination of cosmetics and personal care items in Egypt--shaving creams and shampoos.

We examined a total of 192 samples, including eight different brands of shaving cream and eight brands of shampoo, for their total aerobic bacterial, coliforms and fungal counts. Shaving creams were more heavily contaminated with bacteria than shampoos. Viable bacterial were not recovered from 57% and 10% of shampoos and shaving creams, respectively.

Microbial contamination of cosmetics and personal care items in Egypt--eye shadows, mascaras and face creams.

We examined a total of 150 samples, including 27 eye shadows, 27 mascaras and 96 face creams, for their microbial contents. Mascaras were generally more contaminated than eye shadows. More than 75% of the examined eye shadows contained fewer than 100 c.