Increasing need for materials with special features have brought various new inventions,one of the most promising hope for new material with special features and functionalities is composites materials.Thus,this study...Increasing need for materials with special features have brought various new inventions,one of the most promising hope for new material with special features and functionalities is composites materials.Thus,this study report an integration of zinc nanoparticles into kenaf/polyester polymer composite to introduce new behavior to the composite.The composite behaviors were compared for mechanical,thermal,moisture absorption and biodegradability properties.Prepared Zinc Oxide nanoparticles entrenched in the kenaf/polyestaer composites net structure through chemical bonds between kenaf/ZnO/polyester resin,existence of ZnO significantly influence the mechanical and thermals properties of composites.Thermal analysis based on(TGA)response revealed the integration of ZnO nanoparticles improved the thermal stability when thermal decomposition temperature beyond 3650 C.The thermal cracking decreased with present of ZnO and increase with kenaf content(layers).The modulus,Tensile strength,break at elongation,flexural modulus,flexural strength and impact strength of the composites with higher content kenaf/ZnO nanoparticle are 560 MPa,58MPa,1.8%,1300 PMa,68 MPa and 31 MPa,respectively.Thus,addition of kenaf layers and ZnO results in larger mechanical properties enhancement,the results of the contact angle show improvement in wetting of the fibres with addition of ZnO nanoparticles.展开更多
Due to their excellent dielectric properties and the rapid response to microwave irradiation,silicon carbide nanowhiskers(SiCNWs)were employed as microwave susceptor in this study to absorb microwave and locally melt ...Due to their excellent dielectric properties and the rapid response to microwave irradiation,silicon carbide nanowhiskers(SiCNWs)were employed as microwave susceptor in this study to absorb microwave and locally melt the surrounding polypropylene(PP)substrates for the joining of PP substrates.Complete welded joint is formed after the melted PP was cooled and resolidified.Other than microwave susceptor,SiCNWs also acted as the nanofillers in strengthening the welded joint through the formation of SiCNWs reinforced PP nanocomposite at the interface of PP substrates.Besides,the effect of microwave power on the microwave welding of PP substrates using SiCNWs as susceptor was studied and reported.It was found that the tensile strength and modulus of elasticity of the welded joint improved as microwave power increased.However,it deteriorates the flexibility of the welded joint as high stiffness SiCNWs were incorporated deeper into the PP matrix which restricted the PP chain mobility.Aside from microwave power,clamping pressure is also critical in determining the mechanical properties of a welded joint.When compared to unclamped welded joint,the tensile strength,modulus of elasticity and flexibility of welded joint subjected to clamping pressure improved drastically.Moreover,the tensile strength of welded joint increased when the clamping pressure was increased from P1 to P3,but decreased when the clamping pressure was further increased to P4 due to the occurrence of flashing at welded joint.The formation mechanism of SiCNWs reinforced PP welded joint was also proposed in this study.Compared to conventional welding,this welding process is easy,straightforward and is able to produce welded joint with outstanding mechanical properties via precise controlling of the processing parameters.Thus,microwave welding is thought to offer an option for the joining of thermoplastics and other applications.展开更多
This paper presents the optimization process in sol-gel technique to synthesize Titanium dioxide (TiO2) thin films using in-house Nano-TiO2 powder. Nano-TiO2 powder was previously synthesized in our lab from ilmenite ...This paper presents the optimization process in sol-gel technique to synthesize Titanium dioxide (TiO2) thin films using in-house Nano-TiO2 powder. Nano-TiO2 powder was previously synthesized in our lab from ilmenite which is a tin mining byproduct using a modified hydrothermal method. By varying the mass of Nano-TiO2 powder and acetic acid (catalyst) concentration in the sol-gel process, highly transparent TiO2 thin films were obtained. The thin films were characterized by field effect scanning electron microscope (FESEM), atomic force microscopy (AFM), thickness profiler, ultra-violet-visible spectrometer (UV-Vis) and current-voltage (I-V) measurement system. This paper also demonstrates the TiO2 thin films are sensitive towards isopropanol (IPA) solution where the I-V response of the thin films changed sharply as IPA was dropped onto the thin film’s surface. The electrical property shows the thin film has potential applications for chemical sensors and solar cells.展开更多
文摘Increasing need for materials with special features have brought various new inventions,one of the most promising hope for new material with special features and functionalities is composites materials.Thus,this study report an integration of zinc nanoparticles into kenaf/polyester polymer composite to introduce new behavior to the composite.The composite behaviors were compared for mechanical,thermal,moisture absorption and biodegradability properties.Prepared Zinc Oxide nanoparticles entrenched in the kenaf/polyestaer composites net structure through chemical bonds between kenaf/ZnO/polyester resin,existence of ZnO significantly influence the mechanical and thermals properties of composites.Thermal analysis based on(TGA)response revealed the integration of ZnO nanoparticles improved the thermal stability when thermal decomposition temperature beyond 3650 C.The thermal cracking decreased with present of ZnO and increase with kenaf content(layers).The modulus,Tensile strength,break at elongation,flexural modulus,flexural strength and impact strength of the composites with higher content kenaf/ZnO nanoparticle are 560 MPa,58MPa,1.8%,1300 PMa,68 MPa and 31 MPa,respectively.Thus,addition of kenaf layers and ZnO results in larger mechanical properties enhancement,the results of the contact angle show improvement in wetting of the fibres with addition of ZnO nanoparticles.
基金financially supported by the Department of Education,Ministry of Education Malaysia(MOE)through Fundamental Research Grant Scheme(FRGS/1/2019/TK05/UNIMAP/02/7)[FRGS 9003-00729]。
文摘Due to their excellent dielectric properties and the rapid response to microwave irradiation,silicon carbide nanowhiskers(SiCNWs)were employed as microwave susceptor in this study to absorb microwave and locally melt the surrounding polypropylene(PP)substrates for the joining of PP substrates.Complete welded joint is formed after the melted PP was cooled and resolidified.Other than microwave susceptor,SiCNWs also acted as the nanofillers in strengthening the welded joint through the formation of SiCNWs reinforced PP nanocomposite at the interface of PP substrates.Besides,the effect of microwave power on the microwave welding of PP substrates using SiCNWs as susceptor was studied and reported.It was found that the tensile strength and modulus of elasticity of the welded joint improved as microwave power increased.However,it deteriorates the flexibility of the welded joint as high stiffness SiCNWs were incorporated deeper into the PP matrix which restricted the PP chain mobility.Aside from microwave power,clamping pressure is also critical in determining the mechanical properties of a welded joint.When compared to unclamped welded joint,the tensile strength,modulus of elasticity and flexibility of welded joint subjected to clamping pressure improved drastically.Moreover,the tensile strength of welded joint increased when the clamping pressure was increased from P1 to P3,but decreased when the clamping pressure was further increased to P4 due to the occurrence of flashing at welded joint.The formation mechanism of SiCNWs reinforced PP welded joint was also proposed in this study.Compared to conventional welding,this welding process is easy,straightforward and is able to produce welded joint with outstanding mechanical properties via precise controlling of the processing parameters.Thus,microwave welding is thought to offer an option for the joining of thermoplastics and other applications.
文摘This paper presents the optimization process in sol-gel technique to synthesize Titanium dioxide (TiO2) thin films using in-house Nano-TiO2 powder. Nano-TiO2 powder was previously synthesized in our lab from ilmenite which is a tin mining byproduct using a modified hydrothermal method. By varying the mass of Nano-TiO2 powder and acetic acid (catalyst) concentration in the sol-gel process, highly transparent TiO2 thin films were obtained. The thin films were characterized by field effect scanning electron microscope (FESEM), atomic force microscopy (AFM), thickness profiler, ultra-violet-visible spectrometer (UV-Vis) and current-voltage (I-V) measurement system. This paper also demonstrates the TiO2 thin films are sensitive towards isopropanol (IPA) solution where the I-V response of the thin films changed sharply as IPA was dropped onto the thin film’s surface. The electrical property shows the thin film has potential applications for chemical sensors and solar cells.
