Organic-Sulfonate Functionalized Graphene as a High Temperature Lubricant for Efficient Antifriction and Antiwear in Water-Based Drilling Fluid

The lubricity of drilling fluid resistant to high-temperature over 200℃ is still one of the technological breakthroughs. In this study, the graphene modified with sodium dodecylbenzene sulfonate (SDBS) was selected as a resistant to high-temperature lubricant. Our results show that the drilling fluids have high stability after aging at 240°C with the assistance of the SDBS/graphene. Excitingly, the tribological performance test results revealed that the SDBS/graphene exert excellent anti-friction and anti-wear properties. Compared with the base slurry, the friction coefficient and wear rate of the SDBS/graphene slurry are reduced by 76% and 59%, respectively. The deposited film composed of graphene, Al2O3, SiO2, Fe2O3, FeSO4 actualized the protection of the sliding contact zone, proving that the sulfonate group on the SDBS/graphene contributed to prompt the deposition of the graphene and bentonite and then enhanced tribological properties of the drilling fluids. Overall, the graphene modified with SDBS is expected to solve the difficulty to form effective deposited film and poor lubricity of the drilling fluid under high-temperature.

Sodium Dodecylbenzene Sulfonate Assisted Electrodeposition of MnO2@C Electrode for High Performance Supercapacitor

In this work, MnO2&SDBS electrodes with nano-honeycomb morphology were prepared by ultrasound-assisted electrochemical deposition using sodium dodecylbenzene sulfonate (SDBS) as a surfactant agent. The effect and mechanism of SDBS on the morphology of MnO2 nanomaterials during the preparation of MnO2 by electrochemical anodic oxidation was systematically investigated by varying the content of SDBS in the precursor solution. When the SDBS concentration is 2 g\bulletL-1, the resulting electrode has the best electrochemical performance, and the specific capacitance is up to 407 F\bulletg-1 at the current density of 1000 mAg-1. To further enhance its performance, a carbon coating layer was deposited on the surface of the electrode using a method similar to chemical vapor deposition. Finally, the MnO2&SDBS@C electrode with a three-dimensional net-to-film composite structure with a high specific surface area, hierarchical structure and interconnect with nickel foam supports were obtained. The electrode has excellent electrochemical performance, and the specific capacitance is still up to 289 Fg-1 at a high current density of 5000 mAg-1. Furthermore, the specific capacitance of the electrode was maintained at 76.7% after 5000 cycles of charging and discharging at a current density of 2000 mAg−1.

Preparation and characterization of self-crosslinking acrylic emulsion with different fluorocarbon chain lengths

Purpose Fluorine materials have received the keen attention of many researchers because of their water repellency and low surface free energy. The purpose of this paper is to prepare self-crosslinking fluorocarbon polyacrylate latexes containing different fluorocarbon chain lengths by semi-continuous seeded emulsion polymerization technology. Design/methodology/approach Methyl methacrylate (MMA), butyl acrylate (BA), hydroxypropyl methacrylate (HPMA) and fluorine-containing monomers were used as main monomers. The fluorine-containing monomers included hexafluorobutyl methacrylate (HFMA), dodecafluoroheptyl methacrylate (DFMA) and trifluorooctyl methacrylate (TFMA). Potassium persulfate (KPS) was used as thermal decomposition initiator, non-ionic surfactant alkyl alcohol polyoxyethylene (25) ether (DNS-2500) and anionic surfactant sodium dodecylbenzene sulfonate (SDBS) as mixed emulsifier. Findings Through optimizing the reaction conditions, the uniform and stable latex is gained. The polymer of structure was characterized by Fourier transform infrared spectroscopy (FTIR). Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and contact angle (CA) were tested on latex films. The particle size and distribution range of emulsion were tested with nano particle size analyzer. After comprehensively comparing the latexes and films prepared by HFMA, DFMA and TFMA, the performance of DFMA monomer modified is better. Originality/value The self-crosslinking acrylic emulsion is prepared via semi-continuous seeded emulsion polymerization, which methyl methacrylate (MMA), butyl acrylate (BA), hydroxypropyl methacrylate (HPMA) and fluorine-containing monomers were used as main monomers. The fluorine-containing monomers were composed of hexafluorobutyl methacrylate (HFMA), dodecafluoroheptyl methacrylate (DFMA) and trifluorooctyl methacrylate (TFMA). Potassium persulfate (KPS) was used as thermal decomposition initiator, non-ionic surfactant alkyl alcohol polyoxyethylene (25) ether (DNS-2500) and anionic surfactant sodium dodecylbenzene sulfonate (SDBS) as mixed emulsifier. There are two main innovations. One is that the self-crosslinking acrylic emulsion is prepared successfully. The other is that the effects of monomers containing different fluorocarbon chain lengths on polyacrylate, such as monomer conversion rate, coagulation rate, mechanical stability, chemical stability, emulsion particle size and storage stability, are studied in detail.

Enhanced Anti-Corrosion Performances of Epoxy Resin Using the Addition of Sodium Dodecylbenzene Sulfonate-Modified Graphene

The improvement of anti-corrosive property of epoxy resin is significant for the development of coatings to avoid metal corrosion and thus to reduce the economic loss in many industries. The superior properties of graphene, a two-dimensional material, make it possibly suitable to fulfill this task. However, this is hindered by the easy agglomeration of graphene layers in solvents. In the present work, we report the modification and stabilization of graphene in water using sodium dodecylbenzene sulfonate (SDBS) and the enhancement of the anti-corrosive properties of epoxy resin by mixing such SDBS-modified graphene layers. The influence of the dosage of SDBS on the modification effect of graphene was studied in detail and an optimized dosage, i.e., 50 mg SDBS for 10 mg graphene, was obtained. The SDBS modification could effectively reduce graphene thickness, and the minimum thickness of the modified graphene was 3.50 nm. The modified graphene had increased layer spacing, and the maximum layer spacing was 0.426 nm. When the modified graphene was added into the epoxy resin, the electrochemical impedance modulus value evidently increased compared to pure epoxy resin and those incorporated by pure graphene, indicating that the anti-corrosion performance was significantly improved. These results clarified that SDBS could effectively modify graphene and the SDBS-modified graphene could subsequently largely improve the anti-corrosive property of epoxy resin, which is of significance for the anti-corrosive coatings.