Synthesis and Biocidal Activity of Some Naphthalene-Based Cationic Surfactants

In this study, different cationic surfactants were prepared by reacting dodecyl bromide with tertiary amines to produce a series of quaternary ammonium salts that were converted subsequently to stannous and cobalt cationic complexes via complexing them with stannous (II) or cobalt (II) ions. Surface properties such as surface- and interfacial-tension, and the emulsifying power of these surfactants were investigated. The surface parameters including critical micelle concentration, maximum surface excess, minimum surface area, tension lowering efficiency and effectiveness were studied. The free energy of micellization and adsorption were calculated. Antimicrobial activity was determined via the inhibition zone diameter of the prepared compounds, which was measured against six strains of a representative group of microorganisms. The antimicrobial activity of some of the prepared surfactants against sulfate reducing bacteria was determined by the dilution method. FTIR spectra, elemental analysis and a H1 NMR spectrum were examined to confirm compound structure and purity. The results obtained indicate that these compounds have good surface properties and good biocidal effect on broad spectrum of micro organisms

BEHAVIOR OF DELAYED ADDITION TIME OF SNF SUPERPLASTICIZER ON MICROSILICA-SULPHATE RESISTING CEMENTS

Most concrete produced today includes either chemical additions or chemical admixtures added to concrete, or both. These additives alter the properties of cementitious systems, including fluidity, hydration kinetics, microstructure and strength. Therefore, the development and use of the most suitable type, optimum dosage and delayed addition time (DAT) of superplasticiser in concrete technology have been of increasing importance. The present investigation aimed to evaluate the influence of DAT of sulfonated naphthalene formaldehyde (SNF) condensate on the hydration kinetics of sulfate resisting cement (SRC) pastes incorporating 10 mass % silica fume (SF). Superplasticized cement pastes were prepared using the required water of standard consistency with different dosages and DAT of SNF. The pastes were hydrated for 90 days under normal curing conditions. The results revealed that, the fluidity of cement pastes increases with SNF content and DAT up to 7.5 minutes, due to the electrostatic repulsion between cement particles and the decrease of anhydrous C3A content that is minimized with hydration time. Also, the chemical and physico-mechanical characteristics improve with superplasticizer dosage up to 1.0 mass % and DAT up to 7.5 minutes, due to the improvement of superplasticizing effect, leading to increase the hydration of silicate phases (C3S and β-C2S) and formation of more CSH, CAH and CASH. These hydrates increase the gel/space ratio, modify the microstructure and consequently enhance the strength of cement paste. FTIR spectra are in a good agreement with those of chemical and physico–mechanical characteristics

Cationic surfactant based on alignate as green corrosion inhibitors for the mild steel in 1.0 M HCl

Three cationic surfactants based on alginic acid were laboratory prepared. These compounds were evaluated as corrosion inhibitors utilizing three techniques, namely; weight loss, polarization and electrochemical impedance spectroscopy. The corrosive medium was 1.0 M HCl. The corrosion rate of mild steel in 1.0 M HCl at four different temperatures 25, 40, 55 and 70 °C was investigated gravimetrically. The corrosion rate of mild steel was confirmed electrochemically at 25 °C. It was found that the corrosion inhibition efficiency directly proportionally with the hydrophobic chain length of synthesized inhibitors and also with the plethora of concentration. The inhibition efficiency exhibit a positive trend with raising the solution temperatures as indication for chemisorption. The potentiostatic polarization study revealed that the tested green cationic surfactants act as mixed type inhibitors with predominant control of cathodic reaction. The decreasing in the double layer capacitance obtained from electrochemical impedance measurements refer to increasing the thickness of the formed double layer. The apparent activation energy of the inhibited solution was found to be lower than uninhibited solution as an indication for chemical adsorption

Production of biosurfactant from Bacillus licheniformis for microbial enhanced oil recovery and inhibition the growth of sulfate reducing bacteria

In this study, the bacterium Bacillus licheniformis has been isolated from oil reservoir; the ability of this bacterium to produce a biosurfactant was detected. Surface properties of the produced biosurfactant were confirmed by determining the emulsification power as well as surface and interfacial tension. The crude biosurfactant has been extracted from supernatant culture growth, and the yield of crude biosurfactant was about 1 g/l. Also, chemical structure of the produced biosurfactant was confirmed using FTIR analysis. Results revealed that, the emulsification power has been increased up to 96% and the surface tension decreased from 72 of distilled water to 36 mN/m after 72 h of incubation. The potential application of this bacterial species in microbial-enhanced oil recovery (MEOR) was investigated. The percent of oil recovery was 16.6% upon application in a sand pack column designed to stimulate an oil recovery. It also showed antimicrobial activity against the growth of different strains of SRB (sulfate reducing bacteria). Results revealed that a complete inhibition of SRB growth using 1.0% crude biosurfactant is achieved after 3 h

Production of biosurfactants by Bacillus licheniformis and Candida albicans for application in microbial enhanced oil recovery

In this study, the bacterium Bacillus licheniformis DSM = 13 strain ATCC 14580 and the yeast Candida albicans IMRU 3669 were used for biosurfactant production. Surface properties of the produced biosurfactants were confirmed by determining the emulsification power as well as surface tension. The crude biosurfactants have been extracted from supernatant culture growth. FTIR analysis confirmed the chemical structure of the produced biosurfactants. The yields of crude biosurfactants were about 1 and 12 g/l for B. licheniformis and C. albicans respectively. Also, the results revealed that the emulsification power has been increased up to 96% and 65% with kerosene for bacterial and yeast strain respectively. Surface tension decreased from 72 to 36 mN/m after 72 h of incubation with B. licheniformis and 45 mN/m after 4 days of incubation with C. albicans. The potential application of this bacterial species in microbial enhanced oil recovery (MEOR) was investigated. The percent of oil recovery were 16.6 and 8.6 wt% for the bacterial and yeast strains respectively, upon application in sand pack column designed to stimulate an oil recovery

Effect of some prepared superplasticizers (Cyclohexanone Based) on compressive strength and physico-chemical properties of oil well cement pastes

Two different superplasticizers particularly cyclohexanone formaldehyde sulfanilate (CFS) and cyclohexanone glyoxylic sulfanilate (CGS) were prepared; also, their effect on mechanical and physico-chemical properties of oil well cement was assessed. The chemical structures were affirmed by FTIR technique. The designed chemical compounds were predestined as superplasticizers for cement pastes. The pastes were made by superplasticizer (CFS or CGS) addition to cement by the ratios of 0, 0.25, 0.50, 0.75, and l.00 as mass% of cement. The water of consistency, setting time, chemically combined water content (Wn), the hydration rate and compressive strength of the admixed hardened pastes were predestined at various time periods. The phase composition was intended by DSC and XRD techniques. The results revealed that as the admixture dose rate increases the demand cement paste water of consistency decreases. Also, as the admixture addition rate increases the chemically combined water content decreases, so the rate of hydration decreases; meanwhile compressive strength magnitudes increase accounting for the low water/cement (initial porosity) of the sample

Effect of some prepared superplasticizers on the rheological properties of oil well cement slurries

Three superplasticizers namely: cyclohexanone glyoxylic sulfanilate (CGS), acetone glyoxylic sulfanilate (AGS) and melamine glyoxylic sulfanilate (MGS) were prepared and characterized using FT-IR. The prepared admixtures were evaluated as additives for improving the rheological properties of oil well cement. The effect of temperature (25°, 45° and 65 °C) and admixture dose (0.25, 0.5, 0.75 and 1%) were determined on the apparent viscosity, plastic viscosity and yield stress. The results showed that the prepared superplasticizers, CGS, AGS and MGS decreased these parameters. The results concluded that the CGS, AGS and MGS admixtures act as retarders and dispersant for oil well cement. The three prepared admixtures exhibited high enhancement on the rheological properties which mean that it can use in oil cementing processes. Keywords: Superplasticizers, Rheological properties, Apparent viscosity, Plastic viscosity, Yield stres