Novel polyurethane/graphene nanocomposite coatings

A series of graphene based conductive and anticorrosion coatings were developed in this project. Multi layer coating consists of EPD pristine graphene coating, PU/graphene primer and PU/graphene topcoat was developed. A simple mechanical chemical approach was suggested to fabricate graphene with low cost and high efficiency. XRD was used to characterize the exfoliation efficiency of graphite. TEM was used to examine the size of the graphene sheets. SEM was used to characterize the surface morphology of the coatings. The particle size of all the carbon materials used was characterised by Malvern particle sizer. FTIR and XPS were used to characterize the chemical composition of the graphene powder and the coatings fabricated. MDSC and FTIR were used to monitor the cure dynamic of PU. [Continues.]</div

Carbon based coating on steel with improved electrical conductivity

Graphene and graphite were coated on steel plates by means of Electro Phoresis Deposition (EPD) for electrical conductivity improvement. Thermal treatment was used after EPD to improve the adhesion between the coating layer and the steel substrate. The highest value of the electrical conductivity achieved was 20 times higher than that of the steel substrate. The optimized EPD and thermal treatment conditions were identified. The coating-steel interface and surface structure suggested that good bonding between the coating and the steel substrate was achieved

A study of crystallisation of poly (ethylene oxide) and polypropylene on graphene surface

Crystallisation behaviour of poly (ethylene oxide) (PEO) and isotactic polypropylene (iPP) on graphene surface was investigated by means of polarized microscopy, wide angle X-ray diffraction (WAXD), and Raman techniques. Results indicated that graphene influences the crystallisation and crystal structure of iPP and PEO. WAXD peaks shifting toward lower diffraction angle, i.e. increase in d-pacing, was observed in both PEO and iPP crystallised on the surface of graphene. The change of d-spacing of both PEO and iPP could result from the compressive stress caused by graphene. A shift of 2D band in graphene was observed from Raman spectra. The Raman spectra indicated the big shift in the 2D band is due to the presence of stress induced strain in the polymer attached graphene. The residual stress was generated during crystallization of the polymers on the surface of graphene. Due to the interactions between the graphene and the polymers, the stress was transferred to the graphene which leads to a strain of the graphene. Raman spectra proved the presence of stress generated by the crystallization of the polymers on the surface of graphene

A study of crystallisation of poly (ethylene oxide) and polypropylene on graphene surface

Crystallisation behaviour of poly (ethylene oxide) (PEO) and isotactic polypropylene (iPP) on graphene surface was investigated by means of polarized microscopy, wide angle X-ray diffraction (WAXD), and Raman techniques. Results indicated that graphene influences the crystallisation and crystal structure of iPP and PEO. WAXD peaks shifting toward lower diffraction angle, i.e. increase in d-pacing, was observed in both PEO and iPP crystallised on the surface of graphene. The change of d-spacing of both PEO and iPP could result from the compressive stress caused by graphene. A shift of 2D band in graphene was observed from Raman spectra. The Raman spectra indicated the big shift in the 2D band is due to the presence of stress induced strain in the polymer attached graphene. The residual stress was generated during crystallization of the polymers on the surface of graphene. Due to the interactions between the graphene and the polymers, the stress was transferred to the graphene which leads to a strain of the graphene. Raman spectra proved the presence of stress generated by the crystallization of the polymers on the surface of graphene

Graphene-based conductive coatings

Various in composition and forms, steel have been applied in many different applications such as automotive shell, supporting column and tableware. Graphene, a new era material, has many extraordinary properties such as high tensile strength, high electrical conductivity and barrier properties. It is a very promising material to be utilized as coating to improve a wide range of properties no matter applied as composite or pristine form. Electrophoresis deposition (EPD) has been received increasing interest due to its simplicity and cost effectiveness. Graphene coating layer was deposited by EPD on steel substrates for improved electrical conductivity. Graphene/polyurethane (PU) coatings on steel were prepared as well

Stress transfer in polymer/CNT nanocomposites

A modified model has been suggested for prediction of the Young’s moduli of CNT-polymer composites. In this model, a coefficient of stress transfer between the stiffer nanotubes and the softer polymer matrix was introduced. Empirical relationships among the Young’s modulus, of the CNTpolymer composite, Young’s modulus, of the polymer and volume fraction of the CNTs have been found. In this communication, we will introduce the concept and discuss experimental results