jrups
Abstract : Fabrication and Characterization of Antibacterial and Biodegradable Facial Tissue Papers Using Bio-Based Raw Materials: Effect of Glycerin
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Abstract: Antibacterial facial tissue papers were prepared by solution casting method with chitosan loaded bleached cellulosic pulp. Chitosan, in the film act as an antibacterial agent. Tissue paper films were fabricated by 50% cellulose and 50% chitosan (by weight, dry basis). Mechanical properties of the films were evaluated. It was found that tensile strength (TS) and elongation at break (EB) of the 50% chitosan contain films were 24 MPa and 10.8% respectively. To increase the plasticity of the tissue paper films glycerin was added 0.4 to 2% (by weight). It was found that with the incorporation of 1% glycerin in the tissue paper films the flexibility increased to 50%. Molecular interaction due to the chitosan addition was investigated by Fourier Transform Infra-Red (FTIR) spectroscopy. Water uptake property of glycerin contains films were also evaluated. In the soil medium, the degradation properties of the tissue paper films were carried out. The antibacterial property of the tissue paper was evaluated by disk diffusion method. Keywords: Bleached cellulosic pulp, Chitosan, Glycerin, Facial tissue, Antibacterial, Biopolymer, Biodegradable. |
Abstract : Using Riboflavin as Low Molecular Mass Gelator for the Preparation of a New Network Structure Having Spiroacetal Moieties
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Abstract: The present investigation presents the synthesis and properties of a new nanogel structure based on poly(itaconic anhydride-co-3,9-divinyl-2,4,8,10-tetraoxaspiro[5.5] undecane) and a low molecular mass gelator, namely riboflavin. The chemical structure of the new network system was confirmed by FTIR and 1H-NMR. The sensitivity of the new structures was evaluated by determining the hydrodynamic radius in interdependence with environmental conditions. The investigation was realized as nanogels are considered very attractive carrier systems owing to their nanometer-sized dimensions, which allow for holding large amounts of solvent and incorporating specific compounds in their nanoscale three-dimensional polymer networks. Keywords: Itaconic anhydride, spiroacetal moiety, riboflavin, low molecular mass gelator, polymer network. |
Abstract : A Review Study on the Traditional Machining of Composite Materials
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Abstract: Composite materials are widely used materials in many industrial applications due to their superior properties. Machining of composite materials is difficult to carry out due to the anisotropic and non-homogeneous structures of composites and are mostly prepared in laminate form before undergoing the machining process. Machining of these materials is inevitable although they are manufactured to near net shape. This becomes more important when new product designs and shapes poses tougher dimensional and performance constraints like surface finish, dimensional tolerances & material removal rate etc. Thus many researchers in the past have attempted to study the machining of composite materials to know the effect of various process parameters upon the quality of machining characteristics. In this paper an overview of the various issues involved in the machining of the main types of composite materials is presented. Literature review reveals that current research focuses on the traditional machining of glass and carbon fiber reinforced plastics to reduce or eliminate the problem of delamination and dimensional accuracy. Keywords: Machining, Turning, Grinding, Drilling, Composite Material. |
Abstract : Effect of Side Chain Length on Segregation of Squalane between Smectic Layers Formed by Rod-Like Polysilanes
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Abstract: The segregation of spherical molecules (squalane) between the smectic layers of rod-like polymers (polysilanes) with narrow molecular weight distributions were investigated by synchrotron radiation small-angle X-ray scattering (SR-SAXS), atomic force microscopy (AFM) observations, and molecular dynamics simulations to elucidate the effect of the polymer side chain length on the segregation. It has been theoretically predicted that the smectic phase of the rod-like particles will be stabilized by inserting the spherical particles into the interstitial region between the smectic layers when the diameter of the spherical particles is smaller than that of the rod-like particles whose length is sufficiently long. We found that the segregation of squalane was unaffected by the molecular weight (Mw) of the polysilane in the range of 9,200-44,100 g/mol, and the diameter of the polysilane showed the optimal size of 5.64 nm for the segregation of squalane whose diameter is 6.57 nm although the origin of these inconsistencies between theory and experiment is currently not clear. Keywords: Helical polymer, liquid crystal, smectic phase, depletion effect, rod and sphere. |
Abstract : Generation of Energy from a Single Fuel Cell Using Synthesized Solid Electrolyte Membrane from Functionalized Polyisoprene/ Carbon Nanotubes
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Abstract: Study on the electrical energy generated from a single fuel cell using a synthesized solid electrolyte membrane from polyisoprene that was impregnated with carbonanotubes was carried out. The initial functionalization of the polymer yielded an ion exchange capacity (IEC) of 4.04, 7.82, 11.1 and 15.53 mmol/g with their corresponding degrees of sulphonation (DS) of 10.93, 21.1, 30.03 and 42.02 %, respectively. The later but highest DS achieved water uptake of 49.23 wt % and proton conductivities of 4.3 x 10-3, 1.2 x 10-3 and 2.6 x 10-2 S/cm for membrane of thickness 250, 215 and 120 mm, respectively. The performance testing of the membrane in a single fuel cell achieved an open circuit voltage (OCV) of 647.23 mV with the synthesised membrane of 35 wt % catalyst loading, 589.79 mV and 410.48 mV of 25 wt % and 15 wt % catalyst loading, respectively at constant DS (42.02 %). Their corresponding power densities achieved were 68.67, 49.20 and 35.83 Mw/cm2, respectively. Thus the functionalization of polyisoprene impregnated with carbon nanotubes through the process of sulphonation with chlorosulphonic acid resulted into the development of solid polymer electrolyte membrane for fuel cell application. Keywords: Energy, sulphonation, polyisoprene, carbonanotubes, fuel cell. |