Effects of head group on the properties of cationic surfactants containing hydroxyethyl- and hydroxyisopropyl fragments

A comprehensive review on sustainable surfactants from CNSL: chemistry, key applications and research perspectives

Surfactants, a group of amphiphilic molecules (i.e. with hydrophobic(water insoluble) as well as hydrophilic(water soluble) properties) can modulate interfacial tension. Currently, the majority of surfactants depend on petrochemical feedstocks (such as oil and gas). However, deployment of these petrochemical surfactants produces high toxicity and also has poor biodegradability which can cause more environmental issues. To address these concerns, the current research is moving toward natural resources to produce sustainable surfactants. Among the available natural resources, Cashew Nut Shell Liquid (CNSL) is the preferred choice for industrial scenarios to meet their goals of sustainability. CNSL is an oil extracted from non-edible cashew nut shells, which doesn't affect the food supply chain. The unique structural properties and diverse range of use cases of CNSL are key to developing eco-friendly surfactants that replace petro-based surfactants. Against this backdrop, this article discusses various state-of-the-art developments in key cardanol-based surfactants such as anionic, cationic, non-ionic, and zwitterionic. In addition to this, the efficiency and characteristics of these surfactants are also analyzed and compared with those of the synthetic surfactants (petro-based). Furthermore, the present paper also focuses on various market aspects and different applications in various industries. Finally, this article describes various future research perspectives including Artificial Intelligence technology which, of late, is having a huge impact on society.

Cationic Bola Form Metallosurfactants Based on Isothiouronium, Synthesis and Anti-Microbial Activity

Two series of well-defined dimeric metallo-bolaamphiphiles (bola surfactants) with the coordinated metal ions (Cu, Co, Zn) were prepared. These oligomeric surfactants consist of simple monomeric cationic surfactant fragments which are coupled via the hydrophilic ammonium chloride head groups by C6 and C12 spacer groups of different lengths. FTIR and 1HNMR identification techniques confirmed the obtained products. Measurements of surface tensions showed that the synthesized Bola amphiphiles have the desired, relatively low critical micelle formation concentrations (CMC). Bola amphiphiles with long spacer groups (C12) have a pronounced surface activity. The properties of these cationic surfactant oligomers in aqueous solution such as micellization and surface activity were discussed in relation to spacer group. In addition, the synthesized compounds were examined for their anti-microbial activity using the agar diffusion technique.

Self-assembled systems based on novel hydroxyethylated imidazolium-containing amphiphiles: Interaction with DNA decamer, protein and lipid

The study on aggregation capacity of novel imidazolium-containing amphiphiles of 1-(2-hydroxyethyl)alkylimidazolium bromide series and their interaction with bio-objects (DNA decamer, bovine serum albumin, phospholipid) was performed. It was revealed that introduction of hydroxyethyl moiety into the surfactant molecule resulted in 1.5-2-fold decrease of critical micelle concentration. These modified amphiphiles quantitatively bind DNA decamer due to intercalation and hydrophobic interactions with lipoplex formation. The evaluation of membranotropic properties of these surfactants exhibited that initiation of disordering and compression of the model cell wall consisting of dipalmitoyl phosphocholine (regulation of permeability for various compounds) could be achieved by variation of the length of hydrophobic tail of imidazolium-containing amphiphiles. Transition from individual surfactants solutions to their mixtures with protein (bovine serum albumin) is accompanied by 8-fold decrease of aggregation thresholds and characterized by the presence of two critical points. The binding of components of surfactant/BSA binary systems took place through tryptophan amino acid residue of peptide macromolecule.