Determination of Optimal Electrospinning Distance and Applied Voltage for Polyacrylonitrile Electrospun Fibre Production

Electrospinning process is highly dictated by electric field strength. Thus, two key parameters i.e., electrospinning distance and applied voltage, determine the quality of electrospun fibres. Incorrect selection of these parameters will result in poor fibre qualities. There ought to be an optimal combination of electrospinning distance and applied voltage to produce best quality fibres from a given material. In this study, the optimal combination of electrospinning distance and applied voltage was assessed based on consistency of electrospinning process, amount of fibre, fibre morphology, and average fibre diameter. Polyacrylonitrile (PAN) electrospun fibre samples were prepared at different combinations of electrospinning distance and applied voltage. Scanning electron microscopy and image analysis were conducted to assess the quality and average diameter of the fibres. The results indicate that for electrospinning of PAN, the distance should be between 10 and 20 cm with a 15 to 20 kV of applied voltages. Findings from this study is crucial for producing optimal fibre quality in PAN electrospun nanofibre synthesis

Investigation on fibre diameter, wettability and tensile behaviour of electrospun polyacrylonitrile nanofibres

One of the major concerns in membrane distillation technology is membrane wettability. Surface functionalization using superhydrophobic electrospun nanofibre material is thought to be feasible and effective to overcome the issue. However, further understanding on characteristic and mechanical behaviour of electrospun fibres is required. This paper studied the effect of different electrospinning parameters on fibre diameter, wettability, and tensile behaviour of polyacrylonitrile electrospun nanofibres. Polyacrylonitrile in dimethyl-formamide solution of 10 wt.% concentration was electrospun under different applied voltages and electrospinning distances. The characteristic and behaviour of PAN electrospun nanofibres were characterised by using scanning electron microscope, water contact angle method and tensile test. Based on scanning electron micrographs, the average fibre diameters were in the range of nanometre. It was also observed that increasing the applied voltage would increase the fibre diameter, meanwhile, increasing the distance between spinneret and grounded collector would decrease fibre diameter and fibre deposition rate. The average contact angle and the tensile strength of PAN electrospun nanofibres also was determined in this study. The results from this study provide crucial information for the development of new filtration material for membrane distillation

High-frequency dielectric analysis of carbon nanofibers from pan precursor at different pyrolysis temperatures

Carbon nanofibers (CNF) produced from pyrolysis of electrospun polyacrylonitrile (PAN) precursor has received a great amount of attention due to their promising potentials. However, there are limited studies on the electrical properties of the CNF, especially at high-frequency range. In this study, CNF from PAN precursor were produced by electrospinning technique. Characterizations of the nanofibers were carried out in terms of physical, dielectric, and chemical properties. The stabilization of nanofibers took place at 240°C whilst carbonization process took place at temperatures of 800°C, 1000°C, and 1200°C, respectively. In terms of physical properties, the color of the nanofiber webs changed from white to brown and black, after stabilization and carbonization process accompanied by significant reduction in average fiber diameter. Dielectric analysis of the nanofibers was obtained by measuring the wave propagation characteristics at frequency range of 1 GHz to 10 GHz. Higher dielectric constants of the material were observed for fibers processed at higher carbonization temperatures. Good conductivity was also observed with loss tangent value that is higher than 1. The results were correlated with FTIR transmittance results, indicating greater amount of carbon are present in the nanofiber material. From the findings, the unique behavior of the nanofibers makes it practically potential for sensor applications. Explorations of future research in this area are to be sought

Fabrication of Superhydrophobic Polyacrylonitrile (PAN) nanofibres membranes for membrane distillation technology

Membrane distillation (MD) is a promising water desalination technology that is capable of treating high salinity water. However, the problematic fouling issues and membrane wetting are the primary impediments to the large-scale application of this technology. To overcome the mentioned problems, the distilling membrane should be made from anti-wetting materials and possess a highly porous structure. In this study, a superhydrophobic nanofibrous membrane was fabricated through surface coating of electrospun polyacrylonitrile (PAN) nanofibres membranes using silica nanoparticles and fluorinated alkyl silane surface treatment. The coated PAN nanofibre membranes were characterised using scanning electron microscope (SEM), water contact angle (WCA) method, Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC). It was observed that the amount and size of silica nanoparticle were related to hydrolysis time, which was crucial in determining the membrane pore size and formation of superhydrophobic surface. The presence of silica nanoparticles and fluorine content significantly improved the hydrophobicity and thermal properties of the nanofibres. The results from this study provide valuable insights into the understanding of the behaviour of silica nanoparticles and the method to fabricate superhydrophobic electrospun nanofibre membranes for MD application

Determination of optimal electrospinning distance and applied voltage for polyacrylonitrile electrospun fibre production

Electrospinning process is highly dictated by electric field strength. Thus, two key parameters i.e., electrospinning distance and applied voltage, determine the quality of electrospun fibres. Incorrect selection of these parameters will result in poor fibre qualities. There ought to be an optimal combination of electrospinning distance and applied voltage to produce best quality fibres from a given material. In this study, the optimal combination of electrospinning distance and applied voltage was assessed based on consistency of electrospinning process, amount of fibre, fibre morphology, and average fibre diameter. Polyacrylonitrile (PAN) electrospun fibre samples were prepared at different combinations of electrospinning distance and applied voltage. Scanning electron microscopy and image analysis were conducted to assess the quality and average diameter of the fibres. The results indicate that for electrospinning of PAN, the distance should be between 10 and 20 cm with a 15 to 20 kV of applied voltages. Findings from this study is crucial for producing optimal fibre quality in PAN electrospun nanofibre synthesis

Implementation Of Dark And Raining Environmental Conditions To Investigate Lane Support System Performance For Passenger Cars In Southeast Asia: Case Study For Malaysian Domestic Road

This paper presents a study on the implementation of dark and raining environment test conditions to investigate Lane Support System (LSS) performance for passenger cars in Southeast Asia. The case study has been performed for Malaysian domestic roads. LSS systems involved have been the Lane Departure Warning (LDW) and Lane Keep Assist (LKA). The literature review conducted has revealed that there is not yet a similar study performed for vehicle LSS system. The motivation of this study has been to identify the effect of both environmental conditions on the vehicle LSS performance. This pioneering work is also aimed to help in establishing a new LSS test protocol that could reflect better the driving situations in Southeast Asia countries. The experimental works have been carried out at state road in Melaka, Malaysia. LSS on-road test parameters have been adopted from LSS test protocols from the European New Car Assessment Programme (Euro NCAP) and the Japan National Agency for Automotive Safety and Victim’s Aid (NASVA). A new test procedure to carry out the study has been also developed in this study in order to complement the referred test protocols, including customized rain-making testing equipment to simulate the raining environment conditions. Results from the study have showed that both LDW and LKA systems performance could successfully be evaluated when subjected to dark and raining environment conditions using the new test procedure. Furthermore, the new test procedure developed in this study is also highly applicable for implementation in future LSS on-road tests involving any type of road category (both domestic and highway) with minimal setting up proces