Synthesis, Characterization, and Evaluation of Ethoxylated Lauryl-Myrisityl Alcohol Nonionic Surfactants as Wetting Agents, Anti-Foamers, and Minimum Film Forming Temperature Reducers in Emulsion Polymer Lattices

Staphylococcus aureus-targeting peptide/surfactant assemblies for antibacterial therapy

To address the challenge from microbial resistance, this work developed a surfactant with 18-carbon single hydrocarbon chain and multi-amine head groups (C18N3). After assembling with Staphylococcus aureus-targeting peptide (CARG), the obtained C18N3/CARG assemblies exhibited excellent antimicrobial activities against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus in vitro and in vivo, in which the targeting peptide CARG bonded specifically to Staphylococcus aureus and C18N3 killed bacteria with a mechanism of membrane disruption. Importantly, C18N3 could also work as a β-lactamase inhibitor to overcome the bacterial resistance to β-lactam antibiotics through noncompetitive inhibition. The combination of β-lactam antibiotic and C18N3/CARG assemblies more effectively suppressed methicillin-resistant Staphylococcus aureus in vitro and in vivo relative to equivalent dose of free antibiotic or C18N3. Thus, the antibacterial platform of antibiotic-carrying surfactant assemblies bearing bacteria-targeted peptides, in which C18N3 performed dual function, antibacterial agent and β-lactamase inhibitor, may help fight against the difficult-to-treat infections.

The performance of three novel Gemini surfactants as inhibitors for acid steel corrosion: experimental and theoretical studies

Adipic acid was used to synthesize three nonionic Gemini surfactants containing different numbers of propylene oxide units in their structures. The produced surfactants have been characterized employing FTIR and 1H-NMR spectra. Some of the physical properties of them, namely, surface tension, maximum surface excess concentration, surface pressure, critical micelle concentration, and the minimal area of the surface taken by a single molecule, were computed. The inhibitory effect of the synthesized surfactants on the corrosion of C-steel (C45) in 1.0 M HCl solution was studied. Gravimetric and electrochemical methods were used for corrosion rate measurements. The outcomes acquired from the used methods showed that every one of the three surfactants works as a strong inhibitor for steel acidic corrosion. By raising surfactant concentration and exposure time, the inhibition proficiency improves. The inhibition efficiency exceeded 90% for the three compounds. The higher the propylene oxide units contained in the surfactant molecule the higher is its inhibition efficiency. Based on the findings, a mechanism for inhibitory action was proposed. Moreover, the density functional theory (DFT) and molecular electrostatic potential (MEP) were investigated for the three inhibitors. The calculated parameters were correlated with the inhibition efficiency.

Synthesis, characterization, and functional evaluation of branched dodecyl phenol polyoxyethylene ethers: a novel class of surfactants with excellent wetting properties

A series of branched dodecyl phenol polyoxyethylene ethers (b-DPEO_n) were successfully synthesized via alkylation and ethylene oxide addition reactions. The alkylation reaction was conducted by using a branched internal olefin as the raw material. Furthermore, the conversion rate of the branched dodecene was measured to be 98.1% and the selectivity towards branched dodecyl phenol (b-DP) was 95.9%. Moreover, b-DPEO_n (b-DPEO₇, b-DPEO₁₀, b-DPEO₁₂) were obtained via the reaction of ethylene oxide with b-DP. Notably, b-DPEO₁₀ can efficiently reduce the surface tension of water below 31.55 mN m⁻¹ at the critical micelle concentration (cmc) and the cmc value in water was approximately 1.3 × 10⁻² g L⁻¹ at 25 °C. The preferable wetting ability of b-DPEO₁₀ was superior to that of commercialized dodecyl phenol polyoxyethylene ether (c-DPEO_n), so it will be promoted and used in the textile and pesticide industries.

A series of branched dodecyl phenol polyoxyethylene ethers (b-DPEO_n) were successfully synthesized by using internal olefins with branches, in which branched structures promote good wetting ability.

Synthesis of Five and Six-Membered Heterocycles Using Activated Nitriles for Industrial Applications

The aim of this study is a synthesis of new bioactive heterocyclic compounds incorporated fatty chain for use in different industrial applications. Cyanoacetamide derivative (2) was successfully transferred into five and six membered heterocyclic derivatives by the reaction with various chemical reagents. Addition number of moles of propylene oxide to these compounds gave nonionic surface-active agents having a good solubility, biodegradability and hence lowers the toxicity to human beings and becomes environmentally friendly. The antimicrobial and surface activities were investigated that showed the most of them have pronounced activity, which makes them suitable for diverse applications like the manufacturing of drugs, pesticides, emulsifiers, cosmetics, etc.