Non-ionic Silicone Surfactant Research Articles

Study on wetting mechanism of nonionic silicone surfactant on coal dust

Coal dust disasters are serious in coal mining. The use of nonionic surfactants can effectively improve the wettability of coal dust and reduce the content of suspended coal dust in the air. For the problem of low wettability of ordinary surfactants, this paper selects silicone surfactants with high surface activity and low surface tension to improve the wetting ability of coal dust. To explore the wettability of nonionic silicone surfactants on coal dust, the effects of six nonionic silicone surfactants on the wettability of coal dust surfaces were studied by experiments. The test objects were four kinds of coal samples with different metamorphic degrees. The surface tension, wetting time, and contact angle experiments were carried out, and the critical micelle concentration and the expansion coefficient of the coal surface were calculated. The wetting time of the compound solution was measured to verify the synergistic effect of the compound solution. The results show that: 6 # has the best wetting effect on coal dust, followed by 4 # and 2 #; The order of surface tension is: 1 # < 3 # < 4 # < 6 # < 5 # < 2 #, the surface tension of 1 # is the lowest (19.962 mN/m); 1 # and 4 # are easier to spread on the surface of coal dust, the spreading coefficient of coking coal is the largest and the contact angle is the smallest, which is 18.8°. The 4 # and 6 # with a mass ratio of 8:2 were compounded. The compound surfactant solution had a significant synergistic effect. Compared with the monomer surfactant solution, the wettability of long-flame coal and coking coal increased by 15.14% and 10.00%, respectively. The results of this study can provide reference and experimental support for the development of high-efficiency dust suppressants based on silicone surfactants.

Preparation, Characterization, and Properties of Alkali-Resistant and Hydrolysis-Resistant Silicone Surfactant

It is a challenge to research and develop silicon surfactants with good acid and alkali stability. In the present paper, methylpropenyl polyether modified nonionic silicone surfactant (MPNTS), an alkali-resistant and hydrolysis-resistant silicone surfactant, was synthesized by hydrosilylation of 1,1,1,3,5,5,5-heptamethyl trisiloxane (MDHM) and methylpropenyl polyether (EO(7)). The polyether segments are grafted onto the main chain of organosilicon heptamethyl trisiloxane at a molar ratio of 1:1.05 (n(Si-H):n(C=C)). To evidence product formation, the MPNTS were analyzed by FT-IR and 1H NMR spectroscopy. The surface tension of NPNTS is 18.68 mN/m, and the CMC value is 78 mg/L by a contact angle tester. MPTNS shows hydrolytic stability and maintains that it could keep surface activity after standing for 60 days at pH = 7–10. The compatibility performance analysis shows that MPNTS has good compatibility and synergy with cationic, anionic, and nonionic surfactants, and it reveals the application prospects in daily chemicals, agricultural adjuvants, and other products.

Effect of hydrophilic silica nanoparticles on foam properties of mixtures of silicone and hydrocarbon surfactants

Foams stabilized by nanoparticles (NPs) and surfactants have great application prospects in the development of fluorine-free firefighting foams. In the present study, hydrophilic SiO2 NPs, a nonionic silicone surfactant (CoatOsil-77), and a zwitterionic hydrocarbon surfactant (BS-12) were used to prepare mixed dispersions to investigate effect of NPs on properties of fluorine-free foams. The interactions between NPs and surfactants, foaming ability, and foam stability of the mixed dispersions were investigated. Results indicate that the surface activity, conductivity, and foaming ability of the mixed dispersions decreased with increasing NP concentration. The addition of NPs has a remarkable impact on foam stability of the mixed dispersions. The presence of NPs at a NP concentration above 2% leads to enhancement of foam stability by delaying foam drainage and coarsening. This study provides theoretical guidance for the application of NPs in fluorine-free foams.

Full-color-emitting fluids from carbon dots stabilized in nonconventionally fluorescent micelles.

Red-emitting carbon dots from pyrolysis of citric acid in formamide, which are intrinsically water-insoluble, were solubilized and stabilized by the fluorescent micelles formed by a nonionic silicone surfactant and an anionic surfactant, leading to the formation of full-color-emitting colloids with good biocompatibility and a variety of potential applications.

Clustering-enhanced, nonconventional photoluminescence from a silicone surfactant.

By using the intrinsic nonconventional photoluminescence (n-PL) of organo-siloxane and the synergetic effect of the surfactant mixture, we report strong n-PL from aqueous colloids containing a nonionic silicone surfactant mixed with a traditional anionic surfactant, with an unprecedently high fluorescence quantum yield of up to 85.58%.

Effect of silicones and polymers on the wetting and foaming properties of anionic and nonionic hydrocarbon surfactants.

To better understand the effects of nonionic silicones and polymers on the wetting and foaming properties of anionic and nonionic hydrocarbon surfactants and different forces between molecules, nonionic silicone surfactant (GT-248), polymer (HPMC), anionic surfactant (AES), and nonionic surfactants (APG0810) were selected. The CMC ratio is used as a reference to determine the concentration ratio of the APG0810/GT-248 and AES/GT-248 compound solutions, after which HPMC was added to form a compound solution to test the wetting and foaming properties of the compound solution. The results showed that GT-248 obtained a high density of methyl groups on the surface of the solution due to its excellent spreadability and good flexibility of the siloxane chain, effectively reduces the surface tension and wetting time of AES and APG0810 solutions. But in terms of foam performance, after adding GT-248 to solution, the foam stability of AES solution is enhanced, the foam height of AES solution was reduced by 33.7%, the foam stability of APG0810 solution is weakened a lot, and the foam height of APG0810 solution was reduced by 85.4%. Mainly because of the difference in electronegativity between the AES and APG0810 head groups, the strong electronegativity between the AES head groups resulted in a smaller number of GT-248 insertions in the liquid film, which weakened the defoaming effect of GT-248. The weak interaction between the head groups of APG0810 resulted in a higher amount of GT-248 in the liquid film, and thus, the foam performance was greatly reduced. After the AES/GT-248 compound solution was preferred, by comparing the viscosity, surface tension, and the half-life of the foam, it was found that the addition of low concentration of polymer effectively improved the half-life of the foam without affecting the foaming properties, and the final choice of 4:1(AES/GT-248) + 1mgHPMC and 2:1(AES/GT-248) + 1mgHPMC composite solutions can be used as a superior dust suppression material.

Evaluation of green silicone surfactant-based vortex assisted dispersive liquid-liquid microextraction for sample preparation of organophosphorus pesticide residues in honey and fruit sample.

A vortex-assisted surfactant enhanced emulsification liquid-liquid microextraction based on non-ionic silicone surfactant was successfully developed for the determination of organophosphorus pesticides in food samples coupled to gas chromatography-mass spectrometry. A new type of non-ionic silicone surfactant composed of polysiloxane chains was employed as a green emulsifier to facilitate the emulsification of extraction solvent into the sample matrix, thereby intensifying the mass transfer of target analytes into the organic phase. The variables that affect the extraction were systematically optimized: 80 μl of hexane and 0.5% (v/v) of silicone surfactant were used as extraction solvent and surfactant respectively, the solution was mixed well under vortex agitation for 1 min with the addition of 4% (w/v) sodium sulfate. Under optimum conditions, the linearity of the method was obtained in the range of 0.1-200 μg/kg with a good coefficient of determination varying from 0.9986 to 0.9996. The limit of detection and the limit of quantitation were between 0.008-0.1 and 0.02-0.3 μg/kg, respectively. Application of the proposed method to real samples gave satisfactory recovery values (80%-118%) for the target analytes. The suggested approach has also proven to be convenient, expeditious, and environmentally benign.

Aggregation behavior of a pH-responsive cationic–nonionic silicone surfactant in aqueous solution

A novel pH-sensitive cationic–nonionic silicone surfactant with a tertiary nitrogen head group and poly(ethylene oxide) hydrophilic chain was synthesized and characterized by 1H NMR and FT-IR spectroscopies. The surface activity and micellization behavior under acidic, neutral, and basic conditions were characterized by static surface tension (SST), dynamic surface tension (DST), fluorescence, particle size, and zeta potential techniques. The results showed that the cationic–nonionic silicone surfactant exhibited excellent surface activity, which depended on the aqueous solution pH. Both the critical micelle concentration (CMC) and micelle particle size were significantly different at different pH values. The SST results revealed a change in the CMC of the surfactant from 1.88 g·L−1 at pH 4 to 0.32 g·L−1 at pH 10. Moreover, the mesoequilibrium time, determined by DST, significantly decreased with increasing pH, demonstrating that the interface effectiveness was higher at high pH. The micelle morphology changed from 10 to >100 nm when the pH was varied from 3 to 10. Owing to these properties, the proposed surfactant shows great potential for application in many pH-response-related fields such as coatings, drug carriers, and pesticides.

An environmentally friendly approach to produce single-layer anti-reflective coatings on large surfaces using wet chemical method

Sustainable production of anti-reflective coatings demands environmentally friendly approaches. This paper introduces a novel method of preparing thin films from an aqueous medium using a sol-gel technique. Single-layer anti-reflective coatings, from water-based silica sols, were prepared and characterized. The thicknesses of thin films were found to be between 75 and 135 nm with refractive indexes between 1.23 and 1.41 and porosities between 7 and 53%. The maximum transmissions of manufactured coatings reached from 99.85% to 99.03% in the visible region. The ageing of silica particles in the aqueous medium was studied using TEM. The transparent water-based sol consisted of individual silicon-dioxide nanoparticles with narrow size distribution (15–20 nm). The TEM images showed, that the silica nanoparticles become uniform and distinguishable within two weeks and no aggregation occurs within 46 days. It was found, that the aqueous silica sol is stable and clear for more than 6 months. The aqueous silica films deposited onto large glass surfaces were found to be homogeneous, with excellent adhesion (Cross Hatch Test is 0; ISO 2409 test standard) and hardness equal to 2H. We present a schematic illustration of the adsorption mechanism of non-ionic silicone surfactant and Pluronic surfactant on the silica surface.

Molecular interaction and foaming property of the mixtures of hydrocarbon, fluorocarbon and silicone surfactants

Fluorocarbon surfactants are inevitably involved in industrial applications in combination with hydrocarbon and silicone surfactants, but properties of the ternary mixed system of hydrocarbon, fluorocarbon and silicone surfactants have received little attention, especially foaming ability. In this study, surface activity and aggregation behavior of the ternary mixed system of anionic hydrocarbon (SDS), cationic fluorocarbon (FC-134) and nonionic silicone surfactants (OFX-5211) are studied systematically in order to investigate molecular interaction. Foaming ability of the ternary mixed system is evaluated by Ross-Miles method. Surface activity is characterized by surface tension. Aggregation behavior is obtained by using cryo-transmission electron microscopy (Cryo-TEM). The results show that intense interaction among molecules exists in the ternary surfactant mixture. FC-134 molecules show the interaction with other two surfactant molecules at air/liquid interface and strongest ability to absorb into air/liquid interface. Large vesicles of binary mixture of SDS/OFX-5211 are transformed into irregular micelles upon addition of FC-134. And wormlike micelles of binary mixture of SDS/FC-134 disappeared upon addition of OFX-5211. The foaming ability of the ternary mixtures is higher than that of any of individual surfactant or binary mixtures of surfactants. The intense interaction among molecules promotes the synergistic effect of foaming ability of the ternary mixtures. This study can provide a guidance for the scientific application of hydrocarbon, fluorocarbon and silicone surfactants.

Evaluation of a magnetic activated charcoal modified with non-ionic silicone surfactant as a new magnetic solid phase extraction sorbent with triazine herbicides as model compounds in selected milk and rice samples

The non-ionic silicone surfactant (OFX 0309) has been applied in cloud point extraction for the extraction of triazine herbicides in food samples. Evidence has shown that the non-ionic silicone surfactant demonstrated a good performance as an extractor toward triazine herbicides. In this present study, OFX 0309 surfactant was combined with activated charcoal (AC) due to their valuable properties. Activated charcoal modified with non-ionic silicone surfactant coated with magnetic nanoparticles (AC–OFX MNPs) was synthesized and characterized by FT-IR, VSM, SEM, TEM and BET. This novel material was applied as a magnetic adsorbent for the pre-concentration and separation of triazine herbicides due to hydrophobic interaction between polysiloxane polyether of OFX 0309 surfactant and triazine herbicides. Under optimal conditions, the proposed magnetic solid phase extraction method using AC-OFX MNPs adsorbent was applied to extract triazine herbicides from selected milk and rice samples using high performance liquid chromatography coupled with diode array detector. The validation method revealed a good linearity (1 – 500 μg L–1) with the coefficient of determination (R2) in the range of 0.992–0.998 for the samples. The limits of detection (LOD) of the developed method were 0.04 – 0.05 µg L–1 (milk sample) and 0.02 – 0.05 µg L–1 (rice sample). The limits of quantification (LOQ) were 0.134 – 0.176 µg L–1 (milk sample) and 0.075 – 0.159 µg L–1 (rice sample). The recoveries of the triazine compounds ranged from 81% to 109% in spiked milk samples and from 81% to 111% in spiked rice samples, with relative standard deviations (RSD) values lower than 13.5% and 12.1% for milk and rice samples, respectively. To the best of our knowledge, this is the first study that have investigated the use of magnetic nanoparticles coated activated charcoal modified with OFX 0309 surfactant for pretreatment of triazine herbicides in food samples analysis for simultaneous separation of organic pollutants.

Correction to 'Determination of carcinogenic herbicides in milk samples using green non-ionic silicone surfactant of cloud point extraction and spectrophotometry'.

[This corrects the article DOI: 10.1098/rsos.171500.].

Determination of carcinogenic herbicides in milk samples using green non-ionic silicone surfactant of cloud point extraction and spectrophotometry.

A new cloud point methodology was successfully used for the extraction of carcinogenic pesticides in milk samples as a prior step to their determination by spectrophotometry. In this work, non-ionic silicone surfactant, also known as 3-(3-hydroxypropyl-heptatrimethylxyloxane), was chosen as a green extraction solvent because of its structure and properties. The effect of different parameters, such as the type of surfactant, concentration and volume of surfactant, pH, salt, temperature, incubation time and water content on the cloud point extraction of carcinogenic pesticides such as atrazine and propazine, was studied in detail and a set of optimum conditions was established. A good correlation coefficient (R2) in the range of 0.991–0.997 for all calibration curves was obtained. The limit of detection was 1.06 µg l−1 (atrazine) and 1.22 µg l−1 (propazine), and the limit of quantitation was 3.54 µg l−1 (atrazine) and 4.07 µg l−1 (propazine). Satisfactory recoveries in the range of 81–108% were determined in milk samples at 5 and 1000 µg l−1, respectively, with low relative standard deviation, n = 3 of 0.301–7.45% in milk matrices. The proposed method is very convenient, rapid, cost-effective and environmentally friendly for food analysis.

Performance evaluation of non-ionic silicone surfactants OFX 0309 and DC 193C as a new approach in cloud point extraction - spectrophotometry for determination of atrazine in water samples.

Cloud point extraction (CPE) – spectrophotometric method had been adopted for the separation of atrazine using the non-ionic silicone surfactant, polysiloxane polyether, as a new approach of atrazine extractor in CPE. There were two types of polysiloxane polyether (DC 193C and OFX 0309) studied to investigate the effectiveness of these surfactants toward atrazine in CPE method. Various effects of operating parameters such as the concentration of surfactant and atrazine, addition of salt and change of temperature and pH on the extraction of atrazine have been studied in detail to find the optimum conditions. The limit of detections (LODs) and quantifications (LOQs) were in the range of 0.09–0.59 μg L−1 and 0.31–1.95 μg L−1 in water samples, respectively. The method recoveries at two spiked levels were 84–105% (CPE-OFX 0309) and 59–69% (CPE-DC 193C) with good correlation of determination (R2) ranging from 0.9927–0.9993 for both methods. The Langmuir isotherm has been used for solubilisation study of surfactant and atrazine. The thermodynamic parameters have been determined such as Gibbs free energy (ΔG°) which increases with temperature, value of enthalpy (ΔH°) and value of entropy (ΔS°) which increase with the surfactant hydrophobicity.

Novel concentrated water-in-oil emulsions based on a non-ionic silicone surfactant: Appealing application properties and tuneable viscoelasticity

Silicone excipients are non-irritating ingredients that are extensively used in topical formulations. In the present study, innovative water-in-oil emulsions with a high water content stabilised by a non-ionic silicone surfactant were developed. Effects of formulation composition on its properties and stability were investigated. It was possible to prepare highly stable emulsions with a water volume fraction of up to 80%. The emulsions exhibited desirable application properties such as non-sticky and cooling qualities. A dependency of the viscosity on the water fraction was found; this offers the opportunity to create emulsions with fine-tuned rheological properties.Furthermore, it could be shown in skin studies that the in vitro release of a hydrophilic model drug is influenced by the configuration of the oil phase. The penetration of the silicone surfactant and the other deployed additives was monitored using combined tape stripping and ATR-FTIR experiments, revealing that the compounds remain in the superficial layers of the stratum corneum, thus minimising the risk for skin irritation.

Experimental Study on Foam Properties of Mixed Systems of Silicone and Hydrocarbon Surfactants

AbstractSilicone surfactants are inevitably involved in industrial applications in combination with hydrocarbon surfactants, but properties of the mixtures of silicone and hydrocarbon surfactants have received little attention, especially foam properties of the mixtures. In this study, aqueous solutions of respective binary mixtures of a nonionic silicone surfactant with anionic, cationic, and nonionic hydrocarbon surfactants were prepared for evaluation of their foam properties. Surface tension of aqueous solutions of the mixtures were measured with the maximum bubble pressure method. Foaming ability and foam stability of the mixtures were then evaluated with the standard Ross–Miles method. The findings show that the addition of the silicone surfactant results in a decrease in surface tension for aqueous solutions of the hydrocarbon surfactants. The critical micelle concentration (CMC) of the hydrocarbon surfactants is also changed by the additive silicone surfactant. Additionally, clear foam synergistic effects were observed in the mixtures of silicone and hydrocarbon surfactants, regardless of the ionic types of the hydrocarbon surfactant. The foam stability of the hydrocarbon surfactant was shown to generally improve with the increasing concentration of the silicone surfactant. Even so, aqueous solutions of different ionic hydrocarbon surfactants in the presence of the silicone surfactant will give different foam stabilities. The results of the present study are meant to provide guidance for the practical application of foams generated by the mixtures of the silicone and hydrocarbon surfactants.

Study of removal of phenol species by adsorption on non-ionic silicon surfactant after cloud point extraction methodology

In the present study, CPE was carried out to extract phenol species from aqueous solution using the non-ionic silicone surfactant of DC193C. The non-ionic silicone surfactant of DC193C was chosen because of it is well known as an environmentally friendly solvent. The adsorption mechanism between the non-ionic silicone surfactant of DC193C and phenol species was studied. Our results indicate that, the adsorption of the phenol species from aqueous solution on the DC193C surfactant was in proportion to their hydrophobicities, according to the following order; 4-NP < 2,4-DCP < 2,4,6-TCP. The data of the equilibrium concentration and amount of adsorption in the CPE system for the three phenols species follow the Langmuir-type isotherm. On some assumptions, a developed Langmuir isotherm was used to calculate the feed surfactant concentration required for the removal of the three phenol species up to the extraction efficiency of 90%. The developed correlations may be useful to design a cloud point extractor of a desired efficiency. Thermodynamic parameters including the Gibbs free energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) were also calculated. These parameters indicated that the adsorption of the three phenol species solubilized into the non-ionic DC193C surfactant is feasible, spontaneous, and endothermic in the temperature ranging from 298 to 353 K.

Mixed Micelles of Trisiloxane Based Silicone and Hydrocarbon Surfactants Systems in Aqueous Media: Dilute Aqueous Solution Phase Diagrams, Surface Tension Isotherms, Dilute Solution Viscosities, Critical Micelle Concentrations and Application of Regular Solution Theory

AbstractMixtures of trisiloxane type nonionic silicone surfactant (SS) with sodium dodecylsulfate, tetradecyltrimethylammonium bromide or tert‐octylphenol ethoxylated with 9.5 ethylene oxide groups were studied in water at 30 °C by dilute aqueous solution phase diagrams, surface tension and dilute solution viscosity methods. The cloud points for the silicone surfactant aqueous solutions increased upon addition of hydrocarbon surfactants indicating the formation of hydrophilic complexes in mixture solutions. The scrutiny of the surface tension isotherms plotted as a function of SS concentration revealed that competitive adsorption effects are the characteristic features in these mixtures depending upon the SS concentration. Otherwise the isotherms exhibited two break points and the difference of concentration between the two break points increased with the increase in SS concentration indicating the cooperative nature of interactions. The micellar mole fractions of individual surfactants were determined by Rublingh's regular solution theory; interaction parameters and activity coefficients were evaluated and interpreted in terms of synergistic type interactions in these mixtures. The surface active parameters in mixture solutions were estimated and their analysis shows that the molecular species in the mixture solutions have a preferential tendency for adsorption at the air/water interface than in association form in the bulk solution. The effect of hydrocarbon surfactants on the intrinsic viscosity of SS micelles was monitored and related to the enhanced hydration in mixed micelles.

Layer-By-Layer Assembly of Complex Membranes

Reconstituting complex biological macromolecular and supramolecular structure and function from simple chemical starting materials is the central goal of bottom-up synthetic biology. Phospholipid bilayer membranes, which represent a critically important class of such structures, are central to the study of signal transduction pathways, membrane transport and remodelling, yet controlled assembly of membranes remains more art than science. To address this challenge we developed layer-by-layer (LbL) membrane assembly, the sequential deposition of amphiphile monolayers on microfluidic droplet templates. We have demonstrated LbL assembly of asymmetric, double- and multi-lamellar membranes of defined phospholipid composition and structurally probed these constructs by confocal fluorescence imaging of dye-labeled lipids. Parallel measurement of protein nanopore-mediated transport revealed concerted pore insertion and leakage over multiple vesicles (n > 20). We now demonstrate the amphiphile substrate scope of the technique through assembly and probing of vesicles composed entirely of non-ionic silicone or perfluorous surfactant as well as minimal phospholipids mixtures that mimic both the composition and asymmetry of prokaryotic and eukaryotic plasma membranes. Finally, we demonstrate high-resolution electron microscopy imaging-based validation of the membranes using in situ photo-polymerization, fixing, and membrane staining. LbL assemby provides an extensible and systematic route to natural and synthetic membrane bilayers with diverse chemical configurations in a device architecture that enables structure-function studies of unparalleled reproducibility and control.

Effect of t-octylphenoxylpolyethoxyethanol (TX-100) on the dilute aqueous solution phase diagrams, surface activity and micellization behavior of non-ionic silicone surfactants (SS) in aqueous media

Dilute aqueous solution phase diagrams, surface tension, dynamic light scattering (DLS) and dilute solution viscosity measurements have been made in aqueous solutions of nonionic silicone surfactants (SS) in presence of t-octylphenoxylpolyethoxyethanol (TX-100). Critical micelle concentration, thermodynamic parameters of association, interfacial characteristics such as pC20, surface excess, Γmax , area per adsorbed molecule, a1s along with the size and shape and intrinsic viscosities of the associates have been determined and discussed to ascertain the effect of TX-100 as an additive in SS aqueous solutions. The importance of hydrophobic/hydrophilic (hp/hl) ratio of the SS rather than their molecular architecture and molar mass on their overall interaction with TX-100 micelles has been reflected in the above parameters for the mixture solutions. It was observed that the mixed species in SS aqueous solutions in TX-100 are more hydrophilic in nature and the overall association process in the mixture solutions is entropy driven. TX-100 addition to SS micellar solutions induces the dissociation of SS micelles. As compared to the room temperature, the mixed micelles at elevated temperatures were large in size suggesting that the ellipsoidal micelles in mixed state grow along their major axis that is typically characteristic of the micelles of the individual nonionic SS or TX-100 surfactants at temperatures close to the turbid point.