This paper reports an electrospinning of cellulose nanofiber (CNF) and poly(vinyl alcohol) (PVA) blend for fabricating nanocellulose based long filament in terms of experiment and simulation. To enhance spinnability, Triton X-100 and dimethyl sulfoxide (DMSO) was introduced as a surfactant and cosolvent, respectively. Parameters governing the electrospinning of CNF-PVA blend are voltage, spinning speed, nozzle diameter, the distance between the electrodes, and the viscosity of the blend. Node-based analysis of the electrospinning is performed with electrostatic field modeling via MATLAB software. With the simulation results, proper combinations of parameters are determined for CNF-PVA electrospinning. Furthermore, empirical demonstration of the CNF-PVA electrospinning is achieved. Electospun nanofiber mat is investigated by field emission scanning electron microscopy.
Recently, cellulose fiber reinforced ecofriendly polymer composite for structural material is one of issue due to its sustainability, high mechanical properties, light weight and abundancy. For high strength and sustainable blend, a resin with sustainable, high strength and cellulose compatibility is demanded. PVA-lignin composite is one of good candidate for resin materials due to its high mechanical properties and good adhesion with cellulose. However, low waterproof ability is significant disadvantage of this material. In this paper, esterification reaction with maleic acid was adopted to enhance the mechanical properties. The esterification reaction enhanced waterproof ability and adhesion of PVA-lignin resin to cellulose material.
Cellulose nanofiber (CNF) is an impressive bio resource mainly because of its high mechanical strength, stiffness and optical transparency, which is promising for eco-friendly structural materials. This paper presents the possibility of ecofriendly thin films made with CNF, which has strong, flexible, transparent and lightweight behaviors. The fabrication of thin CNF film and its properties are investigated. Fabrication is carried out by tape casting method to control thickness, followed by separation and drying. Its chemical structure and physical interaction were investigated using Fourier transform infra-red spectroscopy. Mechanical properties are investigated by a tensile test. 3 micron thick CNF film is successfully fabricated. The prepared CNF film is applicable for structural materials in space applications.
In this paper, poly vinyl chloride (PVC) based nano-hybrid composites of multi-walled carbon nanotube (MWCNT) and barium titanate (BT) are prepared by solution casting technique and their morphology and dielectric characteristics are studied. The presence of barium titanate in hybrid composites is confirmed by X-ray Diffraction. Dielectric and morphological studies of PVC-MWCNT composites and PVC-MWCNT-BT hybrid composites also studied to verify the improvement in dielectric properties of PVC-MWCNT-BT hybrid composite compared to PVC-MWCNT composite. The hybrid composites show improved dielectric properties when BT is incorporated as dielectric filler with multi-walled carbon nanotube in PVC. PVC-MWCNT 1 %-BT 3 % hybrid composite showed the highest dielectric constant and the lowest tan δ value among the composites. This hybrid composite is useful for electromagnetic shielding and supercapacitor applications.
Cellulose nanofiber (CNF) isolation from different resources influences the characteristics of the CNF. There are two methods to isolate CNFs, chemical and physical methods. This paper deals with a 2,2,6,6-tetramethylpiperidine- 1-oxylradical (TEMPO-oxidation) chemical method and aqueous counter collision physical method to isolate CNFs. TEMPO-oxidized cellulose nanofiber was isolated using an aqueous counter collision method from two cellulose resource including Softwood bleached kraft pulp (SW) and Hardwood bleached kraft pulp (HW) resources. The CNFs properties were studied by atomic force microscopy, cross-polarize light and UV visible spectrometer. The width of the isolated CNFs is in the range of 15 nm to 20 nm and the length of cellulose nanofibers is around 1000 nm. The HW-CNF offers better transmittance than the SW-CNF. High transmittance of CNF films from both SWCNF and HW-CNF was observed. In addition, the birefringence of CNFs was observed under cross polarized light. The SW-CNF and HW-CNF films showed birefringence phenomenon. More clear iridescence color of HW-CNF sample than that of SW-CNF case.