N-dodecyl Mercaptan Research Articles

Cubic AgBiS2 Powder Prepared Using a Facile Reflux Method for Photocatalytic Degradation of Dyes.

The ternary chalcogenide AgBiS2 has attracted widespread attention in the field of photovoltaic and photoelectric devices due to its excellent properties. In this study, AgBiS2 powders with an average diameter of 200 nm were prepared via a simple and convenient reflux method from silver acetate, bismuth nitrate pentahydrate, and n-dodecyl mercaptan. The adjustment of the ratios of Ag:Bi:S raw materials and of the reaction temperatures were carried out to investigate the significance of the synthesis conditions toward the composition of the as-synthesized AgBiS2. The results of XRD indicated that the powders synthesized at a ratio of 1.05:1:2.1 and a synthesis temperature of 225 °C have the lowest bismuth content and the highest purity. The synthesized AgBiS2 crystallizes in a rock salt type structure with the cubic Fm3¯m space group. Scanning and transmission electron microscopy, thermogravimetric analysis, ultraviolet-visible-near-infrared spectra, and photocatalytic degradation performance were employed to characterize the as-synthesized samples. The results demonstrated that AgBiS2 powders display thermal stability; strong absorption in the ultraviolet, visible, and partial infrared regions; and an optical bandgap of 0.98 eV. The obtained AgBiS2 powders also have a good degradation effect on the methylene blue solution with a degradation efficiency of 58.61% and a rate constant of 0.0034 min-1, indicating that it is an efficient strategy for sewage degradation to reduce water pollution.

Hydrophobic and magnetic fabrication of hydroxyethyl cellulose-lignin aerogel through ultrasound enhancement for efficient oil/water separation

Oil leakage has caused great damage to the marine aquatic environment. Cellulose aerogels can be used to separate oil/water mixture, but the low strength and recyclability have restricted its application. In order to improve the performance of cellulose-based aerogels, hydrophobic and magnetic modification with ultrasound enhancement was carried out. Firstly, hydroxyethyl cellulose-lignin aerogel (CL-aerogel) was synthesized by combining hydroxyethyl cellulose with lignin through sol–gel method with freeze-drying. The incorporation of lignin endowed the aerogel with a 3D porous network and enhanced mechanical properties. Then CL-aerogel was modified with n-dodecyl mercaptan (NDM) and Fe3O4 NPs through ultrasound enhancement to obtain HMCL-aerogel. The results disclosed that with the increase in NDM usage and ultrasound time, the hydrophobicity and magnetic responsiveness of aerogel was enhanced. Furthermore, HMCL-aerogel had good oil absorption capacity with high selectivity. The HMCL-aerogel could be easily recycled by an external magnetic field and could be reused through a simple extrusion treatment. Meanwhile, the aerogel exhibited effective separation of oil/water mixture with a flux as high as 2986 L‧m−2‧h−1 even in corrosive conditions and maintained over 99 % separation efficiency after 10 separation cycles. Therefore, the hydrophobic and magnetic hydroxyethyl cellulose-lignin aerogel could potentially serve as an intriguing candidate for practical oil-polluted wastewater remediation.

Performance of SS304 Modified by Silver Micro/Nano-Dendrite Coating with Hot-Water Super-Repellency in Simulated PEMFC Cathode Environment.

In this study, an silver (Ag) plating with micro/nano-dendrite structures is prepared on the 304 stainless steel (SS304) surface by potentiostatic deposition (Ag/SS304). After being modified by n-dodecyl mercaptan (NDM) with the low surface energy, the obtained sample (NDM@Ag/SS304) exhibits stable superhydrophobicity and excellent hot-water repellency. The surface morphology and composition of NDM@Ag/SS304 are analyzed by scanning electron microscope (SEM), X-ray spectrometer (EDS), X-ray diffractometer (XRD), and X-ray photoelectron spectrometer (XPS) characterization. The electrochemical measurements, tests of water contact angle (WCA), and interfacial contact resistance (ICR) are employed to systematically study the performance of the NDM@Ag/SS304 in the simulated cathode environment of proton exchange membrane fuel cell (PEMFC). The results show that the NDM@Ag/SS304 has high corrosion potential (~0.25 V) and low corrosion current density (~4.04 μA/cm2); after potentiostatic polarization (0.6 V, 5 h), the NDM@Ag/SS304 also shows high superhydrophobic stability.

Hydrophobic Wafer-Scale High-Reproducibility SERS Sensor Based on Silicon Nanorods Arrays Decorated with Au Nanoparticles for Pesticide Residue Detection.

High sensitivity and reproducibility are highly desirable to a SERS sensor in diverse detection applications. Moreover, it is a great challenge to determine how to promote the target molecules to be more concentrated on the hotspots of the SERS substrate by engineering a surface with switching interfacial wettability. Along these lines, wafer-scale uniformly hydrophobic silicon nanorods arrays (SiNRs) decorated with Au nanoparticles were designed as the SERS substrate. Typically, the SERS substrate was fabricated by enforcing the polystyrene (PS) sphere self-assembly, as well as the plasma etching and the magnetron sputtering techniques. Consequently, the SERS substrate was treated by soaking within a n-dodecyl mercaptan (NDM) solution at different times in order to obtain adjustable wettabilities. By leveraging the electromagnetic enhancement resulted from the Au nanostructures and enrichment effect induced by the hydrophobicity, the SERS substrate is endowed with efficient SERS capabilities. During the detection of malachite green (MG), an ultralow relative standard deviation (RSD) 4.04–6.14% is achieved and the characteristic signal of 1172 cm−1 can be detected as low as 1 ng/mL. The proposed SiNRs’ structure presents outstanding SERS activity with sensitivity and reproducibility rendering thus an ideal candidate for potential application in analytical detection fields.

Mussel-inspired fabrication of superhydrophobic cellulose-based paper for the integration of excellent antibacterial activity, effective oil/water separation and photocatalytic degradation

Oily wastewater and organic dye wastewater discharged from modern industry have given rise to serious environmental pollution problem. Noticeably, the integration of superhydrophobicity and photocatalysis provides a facile and efficient way to address these issues. Inspired by mussel-chemistry, we fabricated a multifunctional paper through polydopamine (PDA)-induced in situ growth of Ag nanoparticles (Ag NPs) on paper surface followed by treatment with n-dodecyl mercaptan (n-DM). The resultant paper (PDA@Ag@n-DM) not only exhibited superhydrophobicity, but also displayed excellent antibacterial activity attributing to synergetic effect from bacterial adhesion resistance and photocatalytic bactericidal action. The PDA@Ag@n-DM paper showed good oil absorption capability, excellent separation properties for oil-water mixtures and water-in-oil emulsions, and obvious photocatalytic degradation ability for organic dye under visible light irradiation. Moreover, the PDA@Ag@n-DM paper presented enhanced mechanical, environmental and chemical stability. We believed that the as-prepared multifunctional paper will have great application promising in oily wastewater treatment and environmental remediation.

Fluorination of nitrile-butadiene rubber without gelation via radical graft polymerization in presence of chain transfer agent

Fluorination could efficiently improve the comprehensive performance of nitrile-butadiene rubber (NBR). However, severe gelation usually occurred in the radical graft polymerization onto the diene-based polymers. Here, a facile approach has been established for the facile fluorination of NBR without gelation via radical graft polymerization in presence of n-dodecylmercaptan (NDM) as chain transfer agent, with 2,2,3,4,4,4-hexafluorobutyl acrylate (F6) as the model fluorinating monomer. The gel content decreased with increasing the feeding ratio of NDM and reached 0 with a feeding ratio of NDM of 50 mol% of the initiator, with a fluorination degree of 0.50%. The graft polymerization mechanism was proposed with the 1H NMR analysis. The proposed strategy is expected to provide a promising approach for the functionalization of diene-based polymers.

Superhydrophobic Copper Foam Modified with n-Dodecyl Mercaptan-CeO2 Nanosheets for Efficient Oil/Water Separation and Oil Spill Cleanup

Efficient separation of oil/water with a simple and low-cost method is of great importance for the treatment of oily wastewater. In the current study, a facile one-step electrodeposition method was used to fabricate highly dense CeO₂ nanostructures on copper foam at a constant current density of 1.5 mA·cm–² for 20 min, which exhibited excellent superhydrophobicity and superlipophilicity after surface modification with n-dodecyl mercaptan (NDM). The electrodeposition current density and time were systematically investigated to uncover influencing factors of the growth process of CeO₂ nanostructures on the copper foam. The as-fabricated superhydrophobic foams could not only be used to efficiently separate oil/water mixtures with a separation efficiency greater than 97.4% but also presented robustness and high stability against 3.5 wt % NaCl solution and 600-grit sandpaper abrasion. Furthermore, the as-prepared sample still maintains a high separation efficiency at circa 97.5% after more than 25 times of recovery for kerosene/water mixture separation. In addition, the as-prepared three-dimensional cassette structure made of superhydrophobic copper foam could float freely on the water surface for fast in situ collection of oil from the water surface, indicating application potential in offshore oil spill treatment and cleanup.

Photothermal conversion-assisted oil Water separation by superhydrophobic Cotton yarn prepared via the silver mirror reaction

In this paper, a novel superhydrophobic cotton yarn was prepared for the first time via the surface modification method of silver mirror reaction to form silver nanoparticles on top, followed by the immobilization of n-dodecyl mercaptan (NDM) as the hydrophobic modifier. The modified cotton yarn (CF-Ag-NDM) owns both superhydrophobic and photothermal conversion properties, which synergistically favor the removal of viscous crude oil from water. The average water contact angle of CF-Ag-NDM is 155°. In addition, the photothermal conversion property caused a rapid increasing temperature of the CF-Ag-NDM surface up to 70℃ under one sun radiation in just 2 min, which significantly decreased the viscosity of the crude oil and increased the penetration of oil across CF-Ag-NDM. The oil-water separation efficiency reached as high as 98 % for crude oil and other organic solvents. In addition, CF-Ag-NDM also showed better performance for emulsified oils. Furthermore, CF-Ag-NDM showed excellent temperature resistance, wear resistance, and acid/alkali resistance. A simple lab-made oil-water rotary separation device was also constructed, which achieved excellent crude oil separation from water under one sun radiation.

Thiol-ene Click Chemistry Construct Superhydrophobic Cotton Fabric for High-efficiency Water-in-oil Emulsion Separation

Water pollution severely effects human health and ecosystems. This paper presents a simple method of superhydrophobic cotton fabric fabrication for oil/water separation, We implemented thiol-ene reaction using 3-(Trimethoxysilyl)propyl methacrylate (TMSPMA) and n-dodecyl mercaptan (NDM). to synthesize low surface energy hydrophobic modifier. Superhydrophobic cotton fabrics demonstrated excellent superhydrophobicity, which makes them outstanding materials for continuous and simultaneous removal of insoluble and emulsified oils. Chemical composition, morphology, and hydrophobicity of these cotton fabrics were confirmed by FTIR spectra, scanning electron microscopy (SEM), and water contact angle measurements, respectively. Fabrics samples maintained their superhydrophobic properties even after 20 cycles, separation efficiency was still above 98.5 %. Our superhydrophobic cotton fabric demonstrated a remarkable separation of emulsified oil. We believe that our quick and environmentally friendly method can be used in variety of applications involving water-in-oil emulsion separation and oil purification.

Manipulation of chain transfer agent and cross-linker concentration to modify the performance of fluorinated acrylate latex pressure sensitive adhesive

n-Dodecyl mercaptan (DDM) chain transfer agent and 1,6-hexanediol diacrylate (HDDA) cross-linker were used to manipulate latex properties in a monomer-starved seeded semi-continuous emulsion polymerization of butyl acrylate (BA), fluorine monomer dodecafluoroheptyl methacrylate (DFMA) together with acrylic acid (AA) and 2-hydroxyethyl acrylate (HEA). The influences of both DDM and HDDA on the particle size of the latex, as well as on the gel content, thermostability (differential scanning calorimeter and thermal gravimetric analysis), surface properties (X-ray photoelectron spectra (XPS), contact angle analysis and atomic force microscopy), and viscoelasticity (N,N-dimethylacrylamide) of the polymer films were investigated. The results showed that the introduction of DDM and HDDA has no significant effects on the final particle size of the fluorinated pressure-sensitive adhesives (PSA) latexes. XPS analysis indicated that the fluoroalkyl groups had the tendency to enrich on the surface of the film. However, this enrichment of fluorine on the film surface was reduced after the introduction of HDDA, while increased with the addition of DDM. It was also found that the gel content, glass transition temperature (Tg), thermal stability, surface roughness, and modulus (G′, Gʺ) of the fluorinated latex PSA were all increased with the introduction of HDDA. Nevertheless, opposite trends were observed for the latex after the addition of DDM. Finally, the effects of DDM and HDDA on the adhesive properties (i.e. loop tack, peel strength and shear strength) of the fluorinated latex PSA were also evaluated.

Opposite superwetting magnetic stainless-steel mesh for multiple types of oil/water separation

Oil spill accidents and discharge of oily wastewater from human daily life occur frequently. More and more attention has been paid to wettable interface materials for oil/water separation. However, to date, there has been little reports about on-demand and continuous oil/water separation. Therefore, we proposed a simple and environmentally friendly method to construct rough surface structure by spraying magnetic Fe3O4 nanoparticles, and modified the surface by attaching dopamine and grafting n-dodecyl mercaptan on dopamine to prepare SSM with opposite wetting properties. The obtained meshes exhibit excellent resistance to mechanical and chemical damages, and can be long-term storage. More importantly, the as-prepared superhydrophilic mesh and superhydrophobic mesh can be used to continuously separate oil-water mixtures with high efficiency. At the same time, they could be controlled by magnetic force, and have the application prospect in sewage treatment, oil-water separation and deep-sea oil leakage treatment.

A facile strategy toward hydrophobic–oleophilic 3D Fe foam for efficient oil–water separation

In this work, we present a hydrophobic–oleophilic Fe foam for oil–water separation. Hydrophobic–oleophilic Fe foam was fabricated simply through dip-coating with n-dodecyl mercaptan. The morphology, chemical composition and water contact angle of the Fe foam were characterized. The Fe foam could absorb a variety of oils, such as diesel, toluene, xylene, cyclohexane, dodecyl methacrylate, crude oil, 1,2-dichloroethane, hexane and chloroform, these oils could be underwater or on water surface, and it exhibited excellent durability, verified by the high separation efficiency (more than 98.8% for a cyclohexane–water mixture) after reusing for 48 times. Furthermore, oil collection with the Fe foam could be controlled remotely using external magnetic field, and the Fe foam displayed high flux, good anti-corrosion and wear resistance. The simple and low-cost fabrication method enabled the Fe foam to be a promising candidate for large-scale oil–water separation and for remotely controllable water purification.

Mussel-inspired construction of multifunctional cotton fabric with superhydrophobicity, conductivity and antibacterial activity

Using a facile strategy to fabricate multifunctional cotton fabrics with superhydrophobicity, conductivity and antibacterial activity is an important and urgent issue in the development of natural fabrics. Herein, a new type of cotton fabric, denoted as Cot@PDA/Ag/NDM, has been fabricated utilizing mussel-inspired polydopamine (PDA) chemistry, followed by electroless Ag plating and n-dodecyl mercaptan (NDM) self-assembly. The influence of dopamine (DA) and AgNO3 concentration on the surface morphology and conductivity, as well as NDM treatment time on the surface wettability of the fabric is systematically investigated. Cot@PDA/Ag/NDM not only exhibits superhydrophobicity with water contact angle of 155.9 ± 1°, but also possesses excellent self-cleaning and antifouling properties. In addition, the fabric has a highly conductive surface with sheet resistance as low as 10.2 Ω cm, and shows outstanding mechanical properties and antibacterial activity against Escherichia coli and Staphylococcus aureus.

Investigation of mercaptan/ε-caprolactam initiated bulk copolymerization of methyl methacrylate with vinyl monomers

The bulk copolymerization of methyl methacrylate (MMA) with vinyl monomers initiated by e-caprolactam (CL) and n-dodecyl mercaptan (RSH) was investigated. Acrylonitrile (AN) and vinyl acetate (VAc) were used to copolymerize with MMA at 90 °C in the presence of CL and RSH, respectively. As evidenced by first-order kinetics of polymerization, linear increase of molecular weights with monomer conversions, and relatively low PDI values within a range of 1.3 to 1.6, both the copolymerization reactions exhibited living characteristics. Dependences of the copolymerization on the monomer feed ratio was also studied. An increase in the feed ratio of MMA induced an increased rate of copolymerization. In contrast, an increase in the initial loading of vinyl monomer leaded to the decrease in rate of copolymerization. The reactivity ratios of each pair of comonomers were also assessed using Fineman-Ross (FR) method. The results showed that the CL has an important influence on the kinetics of copolymerization, which caused the copolymerization parameters different from the most previously reported values.

Photo-reduction of Ag nanoparticles by using cellulose-based micelles as soft templates: Catalytic and antimicrobial activities

Amphiphilic cellulose derivatives were synthesized from allyl cellulose (AC) and cystein (Cys)/n-dodecyl mercaptan (NDM) via the thiol-ene click reactions. The derivatives were self-assembled into micelles in distilled water, and the micelles sizes increased with an increase of the DSNDM. The amphiphilic cellulose micelles were served as the soft templates for the controllable synthesis of Ag nanoparticles (NPs) through the photo-reduction. Ag NPs were embedded and stabilized by the amphiphilic cellulose micelles, and their sizes increased from 3.1 to 14.4 nm with an increase of the original template sizes. The catalytic properties of the Ag-loaded micelles were evaluated by the reduction of p-nitropheonl to p-aminophenol. The results demonstrated that the Ag-loaded micelles exhibited excellent catalytic activity. The reduction followed the first-order rate law, and the reaction constant decreased with increasing size of Ag NPs. Moreover, the Ag-loaded micelles displayed good antimicrobial activities to both S. aureus and E. coli. Therefore, the Ag-loaded cellulose-based micelles have potential applications in various fields.

Incorporation of vinyl silane and epoxy silane oligomer into 2-EHA-based polyacrylate latexes via mini-emulsion polymerization and investigation of pressure-sensitive adhesive properties on polar and nonpolar surfaces

Pressure-sensitive adhesives (PSAs) form a bond to various surfaces when a light pressure is applied. PSAs combine the ability of being sticky with elasticity at definite proportions regarding the application area. The adhesion and cohesion mechanisms are well defined as peel adhesion, loop tack and shear strength in the literature and can be adjusted according to the specific requirements. On the purpose of having high peel adhesion and loop tack values without sacrificing the shear strength, 2-ethylhexyl acrylate-based latexes have been synthesized via mini-emulsion polymerization and latexes with high surface area were obtained enabling interactive relation with polar and nonpolar surfaces. Two types of silane selected among the mostly used species in industry were employed to increase the intermolecular interactions and proposed an approach for the incorporation of said compounds referring to the increasing demand of silane utilization in industry. N-dodecyl mercaptan was used as both chain regulator to adjust the molecular weight and cosurfactant to have colloidally stable hydrophobic particles in mini-emulsion polymerization. The incorporation of vinyl silane predominately led to an increase in shear strength owing to chemical cross-linking between chains. Epoxy silane oligomer, on the other hand, increased the peel adhesion and loop tack values considerably compared to the case of vinyl silane. The type of silane incisively affects the PSA properties and should be taken into consideration while constructing a polymer for a pre-specified application. The assumptions in question were strongly correlated with peel, shear and loop tack values, cross-linking density, molecular weight and gas chromatography measurements.

Flotation of fine pyrite by using N-dodecyl mercaptan as collector in natural pH pulp

Laboratory and pilot-scale flotation tests were conducted to investigate the effect of N-dodecyl mercaptan (NDM) on the flotation of fine pyrite. At bench scale, NDM resulted in higher recovery, and the mixed collector of NDM and potassium isoamyl xanthate (PIAX) (mass ratio of 2:1) caused the highest recovery of 96.5%. High grade and recovery of pyrite was obtained without adding any activator (CuSO4) and modifier (H2SO4) in a natural pH of the pulp. Pilot-scale tests indicated that a concentrate with the grade of 50.05% S, 42.23% Fe and the recovery of 98.51% S, 96.69% Fe was achieved by using the mixed collector of NDM+PIAX at pH 6.5.

Modification of cotton fabric by mussel-inspired for oil/water separation

An oil/water separation cotton fabric with high separation efficiency has been successfully developed by combining mussel-inspired one-step copolymerization approach and Michael addition reaction. The cotton fabric was first coated with the adhesive polydopamine (PDA) film by simple immersion in an aqueous solution of dopamine at pH of 8.5. Then n-dodecyl mercaptan (NDM) was conjugated with PDA film through Michael addition reaction at ambient temperature. The chemical structure, surface topography, and surface wettability of the fabric were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, and contact angle experiments, respectively. The results showed that as-prepared cotton fabric had highly hydrophobicity with the water contact angle of 145° and superoleophilicity with the oil contact angle of 0°. It exhibited desirable property of oil/water separation, and it had excellent potential to be used in practical applications and has created a new field for oil/water separation.

A facile method for the fabrication of a superhydrophobic polydopamine-coated copper foam for oil/water separation

A simple dip-coating method was explored to construct hierarchical structures on a 3D copper foam (CF) surface by combining the intrinsic properties of mussel-inspired polydopamine (PDA) and a 3D metal structure. The CF substrate was sequentially modified with PDA and Ag nanoparticles (NPs) and then coupled with n-dodecyl mercaptan (NDM) to create a durable superhydrophobic CF for oil/water separation. The morphology, chemical composition and wettability of the fabricated modified CF surface were characterized. The modified CF surface possesses an increased roughness and exhibits superhydrophobicity, with water contact angle values greater than 150°. The PDA coating on the CF surface can reduce silver ions and anchor the formed NPs onto the surface to construct the hierarchical structure of the superhydrophobic CF. Furthermore, the oil/water separation properties were also investigated. The modified CF can separate a series of oil/water mixtures with a high efficiency and relatively high intrusion pressure. More importantly, the modified CF retains its high efficiency after 30 repeated uses (more than 98% for a dodecane/water mixture), exhibiting excellent durability. The mechanism of oil/water separation is also discussed. The results of this study indicate that the modified CF can serve as a promising candidate for the large-scale separation of oily pollutants from water.

A novel electrodeposition route for fabrication of the superhydrophobic surface with unique self-cleaning, mechanical abrasion and corrosion resistance properties

Inspired by the adhesive proteins in mussels, a novel electrodeposition route has been developed to create multifunctional zinc (Zn)/polydopamine (pDop)/n-dodecyl mercaptan (NDM) composite coatings on different substrates, where oxidative polymerization of dopamine was simultaneously integrated during electrodeposition process. Hierarchical cauliflower-like structure was obtained on the electrodeposited Zn/pDop coatings. After modification with NDM, the prepared Zn/pDop/NDM coatings on different substrates (steel, Al and Cu) possessed excellent superhydrophobicity, exhibiting a maximum water contact angle (WCA) of 167.6° and a sliding angle (SA) less than 1° on the steel substrate. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) were employed to investigate the morphology and the chemical composition of the coatings. The mechanisms of electrodeposition process were discussed. The integrated electrodeposition and polymerization processes promised a synergistic effect on promoting the superhydrophobicity of coating. Results indicated that the dopamine greatly improved the mechanical abrasion resistance of the prepared superhydrophobic coatings. Additionally, these coatings demonstrated superior superhydrophobic stability, corrosion resistance and self-cleaning properties. It is believed that this novel and facile electrodeposition route for fabricating superhydrophobic coatings on various metallic materials will generate great impacts in practical applications.