Synthesis, Spectroscopic Characterization and pH Dependent Electrochemical Fate of Two Non-Ionic Surfactants

Abstract

Two new nonionic surfactants; 1-sec-butyl-3-dodecanoylthiourea (DTU) and 1-dodecanoyl-3-phenylthiourea (DPTU) were synthesized and characterized by 1 H NMR, 13 C NMR and FTIR and UV-Vis spectroscopy. The detailed electrochemical fate of DTU and DPTU was investigated in a wide pH range of 2-12 by employing three electroanalytical techniques. The voltammetric signatures of the analytes showed a single irreversible anodic peak followed by two reversible peaks of the oxidation product. The irreversible behavior of the oxidation process was witnessed by the unequal components of total current in square wave voltammetry and scan rate based deviation of peak potential. The involvement of protons accompanying the electron transfer processes was ascertained from peak potential versus pH plots. Critical micelle concentration and hydrophilic-lipophilic balance of the synthesized surfactants were determined for the assessment of their cleaning, wetting and emulsifying properties. Some detergents and surfactants have been restricted and prohibited in the developed countries due to adverse environmental consequences. The manufacturers are now trying to synthesize environmentally friendly surfactants according to the environmental protection laws.1,2 With these facts in mind, we synthesized thiourea based surfactants which are expected to increase the fertility of the soil if their washed water is directed toward agricultural fields.Surfactants are classified as ionics, nonionics and zwitter-ionics. The demand and consumption of ionic surfactants were greater than nonionics in the mid of 19 century but now the market share of nonionic surfactants has reached to 40% of the total worldwide surfactants production. Nonionic surfactants excel other types due to their neutral behavior, compatibility with ionic surfactants and capability of forming complex mixtures as found in many commercial products. 3,4 Nonionic surfactants are used as excellent solubilizing agents due to their very low critical micelle concentration. 5,6 Such surfactants can work even in hard water as they do not yield ions in aqueous solution and hence, less or almost insensitive to electrolytes. Due to their neutral behavior, nonionic surfactants are none or less toxic than ionic surfactants and hence find use in cosmetics, pharmaceuticals and food products.7-9 They can also be used as wetting agents, emulsifiers and detergents.10,11 Nowadays nonionic surfactants are in constant use in different varieties of domestic and industrial products. 12,13 Prompted by the peculiar characteristics of non-ionic surfactants such as very low critical micelle concentration, insensitivity to hard water, no or low toxicity, low cost and compatibility with ionic surfactants, we synthesized and spectroscopically characterized more effective candidates of this class in high yield using the protocol reported in our recent article.14 Moreover, the oxygen, nitrogen and sulfur donor atoms of thiourea derivatives provide a multitude of bonding possibilities. 15 Hence, the excellent me...

Synthesis of Sulfur‐Based Biocompatible Nonionic Surfactants and Their Nano‐Vesicle Drug Delivery

“…It is well documented that the CMCs of the surfactants decrease with increase in carbon chain length [2]. Surfactants with lower CMCs demonstrate excellent cleaning, wetting, and emulsifying properties [19]. Our results show that both the synthesized surfactants have lower CMC values, confirming their potential utilization in vesicular drug delivery and other applications.…”

Synthesis and Characterization of Sulfanilamide‐Based Nonionic Surfactants and Evaluation of Their Nano‐Vesicular Drug Loading Application

“…The results are in accordance with the reported literature showing that CMC depends upon the lipophilicity of surfactants and with the increasing of lipophilicity of surfactants the CMC decreased (Ullah et al, 2014). Surfactants revealing lower values of CMC are preferred due to superior solubilization, emulsification, wettability, and detergency (Munir et al, 2014). The SAD nonionic surfactants revealed CMC values lower than commercially available surfactants such as lauryl alcohol ether and Brij 35 and peptide amphiphiles that were used in nanodrug delivery (Fan et al, 2016;Patist et al, 2000) thus confirming their effective utilization for various applications including nanovesicular drug delivery.…”

Flavin-sensitized electrode system for oxygen evolution using photo-electrocatalysis

“…A log-log plot of anodic current vs. the scan rate revealed a linear relationship with a slope of 0.95, which is very close to the value of 1 expected for electron transfer by electrode-adsorbed molecules ( Figure 1b) and distinct from the slope of 0.5 expected for diffusion-controlled processes. 31,32 This result clearly demonstrates that the LF was successfully immobilized on the electrode and that the flavin molecules were not released from the electrode surface over the course of the experiment. The separation between the peak potentials, ΔE p (ΔE p = E pa -E pc ), was approximately 46 mV, independent of the scan rate ( Figure S2).…”