Environmentally Friendly Nonionic Surfactants Derived from Tannic Acid: Synthesis, Characterization and Surface Activity

Physicochemical Properties of Nanoliposomes Encapsulating Grape Seed Tannins Formed with Ultrasound Cycles

Grape seeds are an excellent source of flavonoids and tannins with powerful antioxidant properties. However, the astringency of tannins limits their direct incorporation into food. To overcome this challenge, we investigated the encapsulation of grape seed tannins within nanoliposomes formed by ultrasound cycling. We characterized the nanoliposomes' physicochemical properties, including encapsulation efficiency, antioxidant activity, stability, microstructure, and rheological properties. Our findings reveal that the nanoliposomes exhibited excellent stability under refrigerated conditions for up to 90 days with a mean particle size of 228 ± 26 nm, a polydispersity index of 0.598 ± 0.087, and a zeta potential of -41.6 ± 1.30 mV, maintaining a spherical multilamellar microstructure. Moreover, they displayed high antioxidant activity, with encapsulation efficiencies of 79% for epicatechin and 90% for catechin. This innovative approach demonstrates the potential of using ultrasound-assisted nanoliposome encapsulation to directly incorporate grape seed tannins into food matrices, providing a sustainable and efficient method for enhancing their bioavailability and functionality.

Plant polyphenol surfactant construction with strong surface activity and chelation properties as efficient decontamination of UO22+ on cotton fabric

Chemically synthesized surfactants have promising applications in the treatment of uranium, however, their hazardous environmental effects, non-biodegradability, and numerous drawbacks prevent them from being widely used in practice. Herein, we successfully synthesized a green chelating and foaming integrated surfactant (BTBS) by Mannich reaction and acylation of bayberry tannin for the effective removal of UO22+ from aqueous environments or solid surfaces. The as-prepared surfactant was systematically characterized by FT-IR, showing that the hydrophobic groups were successfully grafted onto tannin. The modified material showed better foaming and emulsifying properties, which proved this method could improve the amphiphilicity of tannin. Moreover, for the first time, a foam fractionation method in conjunction with a tannin-based surfactant was applied for UO22+ removal from water. This surfactant was used as a co-surfactant and could readily remove 90 % of UO22+ (20 mg L-1) from water. The removal of UO22+ could be completed in a short time (30 min), and the maximum adsorption capacity was determined as 175.9 mg g-1. This surfactant can also be used for efficient decontamination of uranium-contaminated cotton cloth with a high removal rate of 94.55 %. In addition, the mechanism studies show that the adsorption of BTBS for UO22+ can be mainly attributed to a chelating mechanism between UO22+ and the adjacent phenolic hydroxyls. The novel biomass-derived BTBS with advantages such as high capture capacity, environmental friendliness, and cost-effectiveness suggests that it plays an important role in the remediation of radionuclide pollution.

MOC Composites for Construction: Improvement in Water Resistance by Addition of Nanodopants and Polyphenol

The topic of modification of magnesium oxychloride cement (MOC) using specific functional additives is very much pronounced in the research of alternative building materials. This study deals with the co-doping of MOC by 1D and 2D carbon nanomaterials in order to improve its mechanical properties while using tannic acid (TA) as a surfactant. Furthermore, the effect of TA on MOC also improves its water resistance. As a filler, three size fractions of standard quartz sand are used. The proposed types of MOC-based composites show promising results considering their mechanical, macro- and microstructural, chemical, and hygric properties. The use of 1D and 2D nanoadditives and their mixture enables the improvement in the flexural strength and particularly the softening coefficient, which is the durability parameter characterizing the resistance of the prepared materials to water. After immersion in water for 24 h, the compressive strength of all tested specimens of modified composites was higher than that of the reference composite. Quantitatively, the developed co-doped composites show mechanical parameters comparable to or even better than those of commonly used Portland cement-based materials while maintaining high environmental efficiency. This indicates their potential use as an environmentally friendly alternative to Portland cement-based products.

Novel cationic surfactants: synthesis, surface, antimicrobial studies and applicability as an extracting agent for interested element from monazite mineral concentrate

Two novel cationic surfactants based on palmitic acid were prepared to extract uranium from its fluids. The chemical structures of the surfactants prepared were confirmed spectroscopically. The surface activity of these surfactants was evaluated by measuring their surface tension. The cationic surfactants prepared were also tested for their biological activity against Gram-positive and Gram-negative bacteria and fungi. Subsequently, an attempt was made to use these surfactants to remove uranium from the hydrous oxide cake produced after the alkaline degradation of monazite mineral concentrate. To achieve this goal, several experiments were conducted to determine the optimal conditions for uranium extraction and stripping. Under these optimal conditions, the experimental capacity fitted the pseudo-second order kinetic model. Under the investigated optimal stripping factors of 1 M NaCl, acidified with 0.2 M conc. H2SO4, an A:O ratio of 1:1 and a contact time of 15 min, an uranium stripping efficiency of 83% was obtained for the case study. After the complete stripping process, the marketable uranium concentrate was percipitated using hydrogen peroxide as UO4 H2O with an uranium content of approximately 76%, which was chemically determined and confirmed by EDAX analysis.

Preparation and the foaming activity of hydroxymethyl octadecyltrimethyl ammonium chloride

In this work, hydroxymethyl octadecyltrimethyl ammonium chloride (HM-OTAC) was obtained from the reaction between octadecyltrimethyl ammonium chloride (OTAC) and formaldehyde in different molar ratios. The effects of the reaction conditions (different molar ratios) on the properties of the product (surface tension, foaming, high temperature resistance, methanol resistance and salt resistance) were investigated. The results showed that the HM-OTAC produced under different molar ratios could lower the surface tension of water solutions more than the surfactant OTAC. The HM-OTAC (1:2) reduced the surface tension to 28.29 mN m−1. The HM-OTAC produced under other molar ratios gave higher interfacial tensions than HM-OTAC (1:2). With increasing surfactant concentration, the foam volume first increased and then gradually decreased. At a concentration of 0.3 wt.%, the highest foam volume (460 mL) was produced with HM-OTAC (1:3). Compared to OTAC, the foams produced by each HM-OTAC surfactant exhibited higher temperature stability. In the presence of 30 mL methanol, the initial foam volume of all HM-OTAC surfactants (0.3 wt.%) was generally higher than that of OTAC. With 300 mL HM-OTAC (1:4) solution, the highest foam volume of 20.2 mL could be produced. HM-OTAC (1:3) showed the highest salt resistance.

Study of a high efficient composite foam drainage surfactant for gas production

The foam drainage technique for gas production has the disadvantage of requiring a large amount of surfactant and having low resistance to salt and oil. In this study, a new surfactant mixture (composite surfactant) of lauramidopropyl betaine (LAB-35), α-olefin sulfonate (AOST), sodium alkyl sulfonate (SASE) and cetyltrimethylammonium bromide (CTAB) was tested and its foaming properties were investigated in detail. The foaming properties were determined using high-speed measurements and the Ross-Miles method. The results show that the foaming volume of the composite surfactant can reach 563 mL, indicating that the foaming behaviour of the composite surfactant is more effective than that of the individual surfactants used for the mixture. In addition, the results show that the composite surfactant has a resistance to salt, methanol and condensate oil that most foam drainage agents do not have. However, the stability of the composite surfactant gradually decreases with increasing temperature and concentration. The surface tension was measured and the critical micelle concentration of the composite surfactant is 0.023 g/L.

Growth Inhibition of Sulfate-Reducing Bacteria during Gas and Oil Production Using Novel Schiff Base Diquaternary Biocides: Synthesis, Antimicrobial, and Toxicological Assessment

Upstream crude oil production equipment is always exposed to destruction damagingly which is caused by sulfate-reducing bacterium (SRB) activities that produce H2S gas, which leads to increased metal corrosion (bio-fouling) rates and inflicts effective infrastructure damage. Hence, oil and gas reservoirs must be injected with biocides and inhibitors which still offer the foremost protection against harmful microbial activity. However, because of the economic and environmental risks associated with biocides, the oil and gas sectors improve better methods for their usage. This work describes the synthesis and evaluation of the biological activities as the cytotoxicity and antimicrobial properties of a series of diquaternary cationic biocides that were studied during the inhibition of microbial biofilms. The prepared diquaternary compound was synthesized by coupling vanillin and 4-aminoantipyrene to achieve the corresponding Schiff base, followed by a quaternization reaction using 1,6-bromohexane, 1,8-bromooctane, and 1,12-bromododecane. The increase of their alkyl chain length from 6 to 12 methylene groups increased the obtained antimicrobial activity and cytotoxicity. Antimicrobial efficacies of Q1-3 against various biofilm-forming microorganisms, including bacteria and fungi, were examined utilizing the diameter of inhibition zone procedures. The results revealed that cytotoxic efficacies of Q1-3 were significantly associated mainly with maximum surface excess and interfacial characteristics. The cytotoxic efficiencies of Q1-3 biocides demonstrated promising results due to their comparatively higher efficacies against SRB. Q3 exhibited the highest cytotoxic biocide against the gram +ve, gram -ve, and SRB species according to the inhibition zone diameter test. The toxicity of the studied microorganisms depended on the nature and type of the target microorganism and the hydrophobicity of the biocide molecules. Cytotoxicity assessment and antimicrobial activity displayed increased activity by the increase in their alkyl chain length.

Preparation and the Foaming Activity Study of Hydroxymethyl Cetyltrimethyl Ammonium Chloride

In this paper, hydroxymethyl cetyltrimethyl ammonium chloride (HM-CTAC) was prepared from cetyltrimethyl ammonium chloride (CTAC) and formaldehyde with different molar ratios (1:1 to 1: 4). The effects of reaction conditions (molar ratio) on surface properties were studied, including surface tension, foaming ability, high temperature resistance, methanol resistance and salt resistance. The results show that the minimum surface tension of HM-CTAC is lower than that of CTAC, and HM-CTAC (1:1) has the lowest surface tension of 31.89 mN · m–1. The foam volume of HM-CTAC with different molar ratios is higher than that of CTAC, and HM-CTAC (1:4) has a high foam volume of 435 mL. Compared to CTAC, the HM-CTAC under different reaction conditions has higher temperature resistance. At the methanol content of 10 wt.%, the initial foam volume of HM-CTAC is higher than that of CTAC, and the initial foam volume of HM-CTAC (1:2) is the highest with a volume of 21.5 mL. Among all the surfactants prepared under different reaction conditions, HM-CTAC (1:3) has the highest salt resistance with a relatively stable change in foam volume under different salt contents.

Synthesis and Properties of Octadecyl Trimethyl Ammonium Polyacrylic Surfactants

In order to expand the application range of surfactants, octadecyl trimethyl ammonium chloride (OTAC) and polyacrylic acid (PAA) were used as raw materials to synthesize octadecyl trimethyl ammonium polyacrylic (OTAP). The molar ratios of OTAC to polyacrylic acid monomer were 1:1, 1:2 and 1:3. The synthesized compounds were named as OTAP-1, OTAP-2, OTAP-3. The obtained research results show that the best foaming ability was achieved with OTAP-1, and the best foam stability with OTAP-2. When the concentration was 2.0 g/L, the order of the emulsifying ability was: OTAP-1 > OTAP-2 > OTAP-3; when the concentration was 4.0 g/L, the emulsifying ability order was OTAP-2 > OTAP-3 > OTAP-1. OTAP-1 had a corrosion inhibition capacity of up to 85.11 %, and OTAP-2 and OTAP-3 had a sustained release rate of 81.06 % and 72.82 %, respectively. OTAP-3 had a good effect on scale inhibition, and the scale inhibition rate was 65.01 %.

Synthesis and Interfacial Activity of a New Quaternary Ammonium Surfactant as an oil/gas field chemical

Cationic quaternary ammonium surfactant s are widely applied in many fields, such as detergent, cosmetics, petroleum and natural gas industries. However, the study of the effect of anion on cationic surfactants is rare. To research the influence of anions on the surface properties, a cationic surfactant was prepared, (cetyltrimethyl ammonium isonicotinate, CTAIN), and the surface properties were studied, including surface tension, critical micelle concentration, foaming ability and stability, and corrosion inhibition. The results indicated that the minimum surface tension of CTAIN is lower than that of CTAC, the foaming ability and foaming stability of CTAIN is higher than that of CTAC, and the corrosion inhibition efficiency on mild steel of CTAC is more potent than that of CTAIN. All the results indicate that the new cationic quaternary ammonium surfactant is a useful surfactant in the related fields.