Adsorption, aggregation and wetting behaviors of biodegradable surfactant: Perfluoropolyether quaternary ammonium salt

Strategy for Fabricating Degradable Low-Surface-Energy Cross-Linked Networks with Excellent Anti-Fouling Properties

Marine biofouling negatively impacts marine industries and ship navigation. However, current coatings are based on a single antifouling mechanism, which is insufficient to cope with the complex and ever-changing marine environment. Herein, multifunctional antifouling coatings were developed using a material system containing perfluoropolyether and caprolactone chains. First, an acrylic resin containing perfluoropolyether side chains was synthesized as a liquid-repellent component and then a degradable cross-linked network was constructed by bridging polycaprolactone chains. Surprisingly, polycaprolactone chains not only effectively improved the tensile strength but also provided flexibility to the resin. Thus, the coating exhibited satisfactory mechanical stability and low roughness (4.06 nm) during dynamic polishing. It is worth noting that the cross-linked network with a low surface energy (SE) (22.0 mJ·m-2) effectively inhibited the adhesion of marine fouling organisms. Moreover, the hydrolysis of ester groups promoted the formation of a self-renewing surface, and the synergistic effect of the low SE and degradability of the coating ensured excellent and long-lasting antifouling performance of the coating. The coating reduced the adhesions of Vibrio alginolyticus, Nitzschia sp., and Navicula sp. by 99.99, 84.6, and 91.0%, respectively, compared with their adhesions to a commercially available self-polishing coating (B3000). Thus, the degradable low-SE antifouling coating produced using the proposed strategy can be potentially applied to various maritime industries.

Surface Activity, Wetting, and Aggregation of a Perfluoropolyether Quaternary Ammonium Salt Surfactant with a Hydroxyethyl Group

This paper reports the synthesis of a novel quaternary surfactant containing a hydroxyethyl group (PFPE-C) and the surface properties of its aqueous solution (investigated by comparisons with two structurally similar chemicals, dodecyl-(2-hydroxyethyl)-dimethylammonium chloride (DHDAC) and PFPE-A). The minimum surface tension (γCMC) and critical micelle concentration (CMC) of the PFPE-C aqueous solution were 17.35 mN/m and 0.024 mmol/L, respectively. This study confirms that surfactants containing hydroxyethyl groups efficiently reduce the surface tension of aqueous solutions, and fluorocarbon surfactants exhibit better surface activity than ordinary hydrocarbon surfactants with similar structures. The micellization, aggregation, air-water interfacial adsorption, and wettability of PFPE-C aqueous solutions have been systematically investigated. Highly concentrated PFPE-C aqueous solutions exhibit good wettability on PTFE and paraffin films. Moreover, the aggregates of PFPE-C in the aqueous solution were clearly seen as vesicles on Cryo-TEM micrographs. Primary biodegradation results indicate that 19% of PFPC-C can be degraded within one week.

Syntheses, Properties, and Aggregation Behavior of Novel Carboxylate-Based Silicone Surfactants

Two new anionic silicone surfactants were synthesized for the first time from dichloromethylvinylsilane or trichlorovinylsilane through hydrolysis-condensation and then thiol-ene reactions. Their structures were characterized by FT-IR, ¹ H NMR and ESI-MS. The surface tension (γ), critical aggregate concentration (CAC), surface pressure at CAC ( Π C A C ${\Pi _{C{\rm{A}}C} }$ ) and minimum surface area per surfactant molecule ( A min ${{A}_{\min } }$ ) were studied by surface tension and electrical conductivity, demonstrating their high surface activity at the gas/liquid interface. Transmission electron microscopy measurements showed that uniform spherical aggregates former in aqueous solution for both surfactants. Moreover, the size of the aggregates was determined to be in the range from 50 to 300 nm by dynamic light scattering.

Self-Assembling Drug Formulations with Tunable Permeability and Biodegradability

This review focuses on key topics in the field of drug delivery related to the design of nanocarriers answering the biomedicine criteria, including biocompatibility, biodegradability, low toxicity, and the ability to overcome biological barriers. For these reasons, much attention is paid to the amphiphile-based carriers composed of natural building blocks, lipids, and their structural analogues and synthetic surfactants that are capable of self-assembly with the formation of a variety of supramolecular aggregates. The latter are dynamic structures that can be used as nanocontainers for hydrophobic drugs to increase their solubility and bioavailability. In this section, biodegradable cationic surfactants bearing cleavable fragments are discussed, with ester- and carbamate-containing analogs, as well as amino acid derivatives received special attention. Drug delivery through the biological barriers is a challenging task, which is highlighted by the example of transdermal method of drug administration. In this paper, nonionic surfactants are primarily discussed, including their application for the fabrication of nanocarriers, their surfactant-skin interactions, the mechanisms of modulating their permeability, and the factors controlling drug encapsulation, release, and targeted delivery. Different types of nanocarriers are covered, including niosomes, transfersomes, invasomes and chitosomes, with their morphological specificity, beneficial characteristics and limitations discussed.

Synthesis and application of non-bioaccumulable fluorinated surfactants: a review

Abstract

Due to negative effects of conventional fluorinated surfactants with long perfluorocarbon chain (CxF2x+ 1, x≥7) like perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), these conventional long perfluorocarbon chain surfactants have been restricted in many industrial applications. Nowadays, their potential non-bioaccumulable alternatives have been developed to meet the requirements of environmental sustainable development. In this paper, the recent advances of potential non-bioaccumulable fluorinated surfactants with different fluorocarbon chain structures, including the short perfluorocarbon chain, the branched fluorocarbon chain, and the fluorocarbon chain with weak points, are reviewed from the aspects of synthesis processes, properties, and structure-activity relationships. And their applications in emulsion polymerization of fluorinated olefins, handling membrane proteins, and leather manufacture also are summarized. Furthermore, the challenges embedded in the current non-bioaccumulable fluorinated surfactants are also highlighted and discussed with the hope to provide a valuable reference for the prosperous development of fluorinated surfactants.

Graphical abstract

Synthesis and Properties of Novel Catanionic Surfactant Phosphonium Benzene Sulfonate

A new type of catanionic surfactant phosphonium benzene sulfonate was synthesized by quaternization of triphenyl phosphine with dimethyl carbonate and followed by anion exchange with alkyl benzene sulfonic acid. The molecular structure was characterized by FT-IR, 1H-NMR, and 31P-NMR. The thermal stability of phosphonium benzene sulfonate was evaluated by thermogravimetric analysis (TGA). Its surface properties were studied systematically through equilibrium surface tension, electrical conductivity, and dynamic surface tension measurements. The wettability, foam properties, and emulsification of phosphonium benzene sulfonate were estimated in this paper. TGA results revealed that it has an excellent thermostability and could be used below 350 °C. Equilibrium surface tension results indicated that it has a low critical micelle concentration (CMC, about 0.10 mmol/L), lower than that of ammonium benzene sulfonate and sodium dodecyl benzene sulfonate. Furthermore, the micellization of phosphonium benzene sulfonate in aqueous solution is an entropy-driven spontaneous process. The adsorption process of phosphonium benzenesulfonate at the air-liquid interface is controlled by hybrid kinetic adsorption. Moreover, it has excellent wetting and emulsifying properties and low foam properties.

Laboratory evaluation and numerical simulation of the alkali–surfactant–polymer synergistic mechanism in chemical flooding

Alkali–surfactant–polymer (ASP) flooding, which can reduce interfacial tension (IFT) and the mobility ratio between oil and water phases, has been proven to be effective for enhancing oil recovery in laboratory experiments and field pilots. However, the study of interactions within alkali–surfactant–polymers for chemical flooding is neither comprehensive nor complete until now. Laboratory experiments were conducted and a corresponding numerical simulation model was established to characterize multiple component interactions during the ASP flooding process. Synergistic effects of multiple component interactions on viscosity variation, IFT reduction, and multicomponent adsorption were studied separately. ASP solution viscosity shows non-linear variation behavior with an increasing polymer concentration. Alkali decreases the molecular hydraulic radius of a polymer, and then limits its contribution to viscosity. Oil–water interfacial tension decreases with the join in of polymer which can act as an alternative effect to replace surfactant adsorbed on a mineral surface. Petroleum acid will react with alkali and produce petroleum soap to perform a synergetic action with the surfactant on IFT reduction. Adsorption fraction and diffusion rate of a surfactant will diminish due to rheology improvements caused by a polymer. Alkali can protect a surfactant from adsorption consumption by competitive adsorption. A viscosity non-linear logarithm mixing method, IFT reduction–relative permeability curve interpolation method, and a multicomponent adsorption isotherm model were developed to characterize and simulate the synergistic effects obtained by experiments. A novel ASP flooding numerical simulation model was constructed which coupled the synergistic effects simulation methods of viscosity variation, IFT reduction, and multicomponent adsorption. The numerical simulation result based on the proposed model has better agreement with experiment results compared with that of the traditional model. Validation results proved the effectiveness of the proposed model which can be used to enhance a synergistic mechanism study and field application of ASP flooding.

This paper aims to reveal alkali–surfactant–polymer synergistic mechanism and construct corresponding novel ASP flooding numerical simulation model.

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.