Synthesis of Novel Zwitterionic Surfactants: Achieving Enhanced Water Resistance and Adhesion in Emulsion Polymer Adhesives

Recent advancements in polymer materials have enabled the synthesis of bio-based monomers from renewable resources, promoting sustainable alternatives to fossil-based materials. This study presents a novel zwitterionic surfactant, SF, derived from 10-undecenoic acid obtained from castor oil through a four-step reaction, achieving a yield of 78%. SF has a critical micelle concentration (CMC) of 1235 mg/L, slightly higher than the commercial anionic surfactant Rhodacal DS-4 (sodium dodecyl benzene sulfonate), and effectively stabilizes monomer droplets, leading to excellent conversion and stable latex formation. The zwitterionic groups in SF enhance adhesion to hydrophilic substrates (glass, stainless steel, and skin). Films produced with SF exhibit outstanding water resistance, with only 18.48% water uptake after 1800 min, compared to 81% for the control using Rhodacal DS-4. Notably, SF maintains low water uptake across various concentrations, minimizing water penetration. Thus, the synthesized SF demonstrates improved adhesive properties and excellent water resistance in emulsion polymerization applications, highlighting its potential as a sustainable, high-performance alternative to petrochemical surfactants.

Lipase-catalyzed synthesis of erythorbyl oleate and its characterization as a multifunctional emulsifier

Erythorbyl oleate (EO), a novel emulsifier with multifunctional properties, was synthesized via lipase-catalyzed solvent-free esterification between erythorbic acid and oleic acid. The reaction produced EO of 30.75 ± 1.65 mM at 60 h, monitored by high-performance liquid chromatography (HPLC) analysis. Purified EO was chemically identified as 6-O-oleoyl-erythorbic acid by HPLC-electrospray ionization/mass spectrometry (ESI-MS), 1H nuclear magnetic resonance (NMR), and 13C NMR analyses, and further investigations on its multifunctionalities were conducted. EO displayed antioxidant activity equivalent to erythorbic acid in 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activities. Investigation of the antibacterial activity of EO against foodborne pathogens showed MICs of 0.27 ± 0.09 and 0.40 mM for Bacillus cereus ATCC 10876 and Staphylococcus aureus ATCC 12692, respectively. EO also displayed interfacial properties, lowering interfacial tension between medium-chain triglyceride oil and water to 3.40 ± 0.04 mN/m with a critical micelle concentration of 2.54 ± 0.03 mM. Dynamic light scattering analyses of the emulsion stabilized by EO demonstrated a similar polydispersity index (0.15 ± 0.00) to Tween 80-stabilized emulsion (0.28 ± 0.01), with an average droplet size of 173.2 ± 1.8 nm. In addition, the EO-stabilized emulsion exhibited a negative surface charge (-56.83 ± 4.30 mV) in zeta potential measurements, indicating sufficient electrostatic repulsion between droplets. These results suggest that EO is a multifunctional emulsifier to simultaneously control oxidative rancidification and bacterial spoilage in emulsion-based foods. Practical Application: EO was synthesized via an enzymatic esterification reaction between erythorbic acid and oleic acid. The synthetic process excluded any use of organic solvent, diminishing potential health hazards or environmental pollution associated with chemical reactions. The interfacial properties of the resultant EO, along with excellent antioxidant and antibacterial activities, propose its potential application in emulsion-based foods. Simultaneous control of bacterial spoilage and oxidative rancidification by EO would fulfill the industrial needs for extending shelf life and enhancing consumer safety.

Highly Ca2+-Ion-Tolerant Biobased Zwitterionic Surfactant with High Interfacial Activity

The wide application of surfactants has a harmful effect on the environment, drawing more attention to the development and application of low-toxicity surfactants. A salt-tolerant and low-toxicity biobased zwitterionic surfactant, N,N-dimethyl-N-[2-hydroxy-3-sulfo-propyl]-N-benzyloxyoctadecanoyl-1,3-propanediamine (SPBOPA), was prepared from the oleic acid extracted from waste oils and anise ether extracted from the tarragon. The final surfactant structure was confirmed using gas chromatography-mass spectrometry (GC-MS), liquid chromatography-mass spectrometry (LC-MS), and ¹H nuclear magnetic resonance (NMR) spectroscopy. The SPBOPA surfactant could reduce the interfacial tension between crude oil and formation brine to ultralow (5.2 × 10^-4 mN/m) at a low dosage without extra alkali. It still had good interfacial properties in NaCl up to 60 g/L, Ca²⁺ up to 2000 mg/L, and temperature up to 100 °C. Furthermore, SPBOPA had strong antidilution and antiadsorption properties with low toxicity as demonstrated by the high LD₅₀ value of >5000 mg/kg·BW. It could also enhance the wetting ability of crude oil surfaces. Meanwhile, it showed a high biodegradability in the environment. All of the results achieved in this work confirmed that the SPBOPA surfactant is a more robust and promising biobased surfactant candidate than traditional surfactants as an eco-friendly surfactant for enhanced oil recovery (EOR).

Preparation of Bioderived and Biodegradable Surfactants Based on an Intrinsically Disordered Protein Sequence

Surfactants, block copolymers, and other types of micellar systems are used in a wide variety of biomedical and industrial processes. However, most commonly used surfactants are synthetically derived and pose environmental and toxicological concerns throughout their product life cycle. Because of this, bioderived and biodegradable surfactants are promising alternatives. For biosurfactants to be implemented industrially, they need to be produced on a large scale and also have tailorable properties that match those afforded by the polymerization of synthetic surfactants. In this paper, a scalable and versatile production method for biosurfactants based on a hydrophilic intrinsically disordered protein (IDP) sequence with a genetically engineered hydrophobic domain is used to study variables that impact their physicochemical and self-assembling properties. These amphiphilic sequences were found to self-assemble into micelles over a broad range of temperatures, pH values, and ionic strengths. To investigate the role of the IDP hydrophilic domain on self-assembly, variants with increased overall charges and systematically decreased IDP domain lengths were produced and examined for their sizes, morphologies, and critical micelle concentrations (CMCs). The results of these studies indicate that decreasing the length of the IDP domain and consequently the molecular weight and hydrophilic fraction leads to smaller micelles. In addition, significantly increasing the amount of charged residues in the hydrophilic IDP domain results in micelles of similar sizes but with higher CMC values. This represents an initial step in developing a quantitative model for the future engineering of biosurfactants based on this IDP sequence.

Gemini and Bicephalous Surfactants: A Review on Their Synthesis, Micelle Formation, and Uses

The use of surfactants in polymerization reactions is particularly important, mainly in emulsion polymerizations. Further, micelles from biocompatible surfactants find use in pharmaceutical dosage forms. This paper reviews recent developments in the synthesis of novel gemini and bicephalous surfactants, micelle formation, and their applications in polymer and nanoparticle synthesis, oil recovery, catalysis, corrosion, protein binding, and biomedical area, particularly in drug delivery.

Chemically Triggered Coalescence and Reactivity of Droplet Fibers

We describe the role of functional polymer surfactants in the construction and triggered collapse of droplet-based fibers and the use of these macroscopic supracolloidal structures for reagent compartmentalization. Copolymer surfactants containing both zwitterionic and tertiary amine pendent groups were synthesized for stabilization of oil-in-water droplets, in which the self-adherent properties of the selected zwitterions impart interdroplet adherence, while the amine groups provide access to pH-triggered coalescence. Macroscopic fibers, obtained by droplet extrusion, were prepared with reagents embedded in spatially distinct components of the fibers. Upon acidification of the continuous aqueous phase, protonation of the polymer surfactants increases their hydrophilicity and causes rapid fiber disruption and collapse. Cross-linked versions of these supracolloidal fibers were stable upon acidification and appeared to direct interdroplet passage of encapsulants along the fiber length. Overall, these functional, responsive emulsions provide a strategy to impart on-demand chemical reactivity to soft materials structures that benefits from the interfacial chemistry of the system.

The optimization of heterogeneous catalytic conditions in the direct alkylation of waste vegetable oil

Alkylated waste vegetable oil is a versatile intermediate product in the synthesis of bio-based materials. Heterogeneous catalytic condition with high conversion rate in the direct alkylation of waste vegetable oil was reported and the deactivation mechanism of catalyst was revealed. The total exchange capacity, elemental composition and pyrolysis product of catalyst before and after the alkylation reaction were analysed by back titration, elemental analysis, electrospray ionization mass spectrometry, gas chromatography mass spectrometry and pyrolysis-gas chromatography/mass spectrometry, respectively. The results indicated that the metallic and non-metallic (C, H) elements contents of the catalyst have very much increased with great changes in pyrolysis product and a slight decrease in the total exchange capacity. The formation of insoluble polymers through Diels-Alder cycloaddition between triglycerides was proved to be the major factor causing the dysfunction of the catalytic centre. The metal ions from corrosion of the reactor were the minor factor causing about 2.56% loss of the catalytic centre. Moreover, the catalyst was able to maintain high catalytic efficiency when replacing the raw materials with other waste vegetable oil having low concentration of polyunsaturated fatty acids, which is significant for producing not only the aryl fatty acids derivatives but also the bio-based surfactants.

Systematic evaluation of petroleum sulfonate: polarity separation and the relationship between its structure and oil recovery properties

Petroleum sulfonate is one of the most important surfactants in the tertiary oil recovery process. However, its complex composition significantly impedes its evaluation, and the relationship between its structure and oil recovery properties is still unclear. In this study, the actives of petroleum sulfonate are subdivided into seven components, a–g, with different polarities via column chromatography. The structural information of each component is fully characterized. Moreover, the relationship between the oil recovery properties and the structure of the separated components is systematically studied. The results reveal the average relative molecular mass in the range of 560–626, average alkyl side chain containing 36–40 carbon atoms and alkyl chain containing an average of 6 branched chains is the ideal structure for enhancing oil recovery properties. Furthermore, this study provides a reliable evaluation method and reveals the relationship between the structure and oil recovery properties of petroleum sulfonate.

Petroleum sulfonate actives are efficiently separated and fully characterized, and the relationship between their structure and oil recovery properties is revealed.

A novel binary flooding system of a biobased surfactant and hydrophobically associating polymer with ultralow interfacial tensions

A novel alkali free binary flooding system of a biobased zwitterionic surfactant and hydrophobically associating polymer with ultralow interfacial tension at a low surfactant dosage was studied in this paper.

Interaction mechanisms between polycyclic aromatic hydrocarbons (PAHs) and organic soil washing agents

Understanding interaction mechanisms between polycyclic aromatic hydrocarbons (PAHs) and soil-washing agents can help in choosing efficient agents which are able to desorb and solubilize PAHs. This study investigated interaction mechanisms between pyrene and four washing agents including: two dissolved organic matters (DOM) F-DOM and CRC-DOM, and two commercial bio-based surfactants BBE-1000 and Supersolv using fluorescence spectroscopy combined with multivariate curve resolution alternating regression (MCR-AR). The efficiencies of these washing agents in removing PAHs from the soil were tested in a soil washing experiment. Pyrene showed π-π interactions with F-DOM and no interaction with CRC-DOM. This could be attributed to the more aromatic structures in F-DOM compared to CRC-DOM. The two DOMs were inefficient in soil washing which might be attributed to the relatively weak effect of π-π interactions in releasing PAHs from the soil. Interaction mechanisms between pyrene and the bio-based surfactants were elucidated with MCR-AR, which resolved three spectroscopically active species from pyrene emission spectra as a function of pyrene and bio-based surfactants concentrations. These species resembled pyrene emission in a polar and nonpolar microenvironment, respectively and of an excimer. Concentration profiles retrieved by the model for the three species showed that, below the critical micelle concentration (CMC), Supersolv created more nonpolar interactions with pyrene compared to BBE-1000. In soil washing, Supersolv showed the highest efficiency in extracting PAHs from the soil. This highlighted the importance of nonpolar interactions in desorbing PAHs from soils, which could then be solubilized in micelles. This study demonstrated the potential of fluorescence spectroscopy combined with the MCR-AR model for selecting efficient soil-washing agents.

Synthesis, surface activities, and aggregation behavior of phenyl-containing carboxybetaine surfactants

A novel series of carboxybetaine surfactants were synthesized for the first time and their physicochemical properties were systematically investigated.

Sustainable oleic and stearic acid based biodegradable surfactants

Renewable ester functionalized fatty acid based imidazolium surfactant.

DNA micelles as nanoreactors: efficient DNA functionalization with hydrophobic organic molecules

We report a micelle-templated method to enhance the reactivity of DNA with highly hydrophobic molecules. Lipids, chromophores and polymers can be conjugated to DNA in high yield and under mild conditions. This method expands the range of DNA-templated reactions for DNA-encoded libraries, oligonucleotide and drug delivery, nanopore mimetics and DNA nanotechnology.

The Rebirth of Waste Cooking Oil to Novel Bio-based Surfactants

Waste cooking oil (WCO) is a kind of non-edible oil with enormous quantities and its unreasonable dispose may generate negative impact on human life and environment. However, WCO is certainly a renewable feedstock of bio-based materials. To get the rebirth of WCO, we have established a facile and high-yield method to convert WCO to bio-based zwitterionic surfactants with excellent surface and interfacial properties. The interfacial tension between crude oil and water could reach ultra-low value as 0.0016 mN m⁻¹ at a low dosage as 0.100 g L⁻¹ of this bio-based surfactant without the aid of extra alkali, which shows a strong interfacial activity and the great potential application in many industrial fields, in particular, the application in enhanced oil recovery in oilfields in place of petroleum-based surfactants.