Fabrication of nanofibrous biomaterials based on natural materials (collagen, gelatin, etc.) through various techniques is an important research topic. Electrospinning, a well-established technique for nanofiber production has also been extended for producing nanofibrous structures of natural materials. Collagen nanofiber production utilizes hexafluoro isopropanol (HFIP) as a solvent for electrospinning. Research efforts are now focused on replacing HFIP with an environmentally benign solvent. In this study, electrospinning of Type I collagen of bovine skin with polycaprolactone (PCL) as a blend and an environmentally benign solvent, acetic acid, was carried out. The samples produced were subjected to contact angle measurements, porosity estimation, SEM, FTIR, TGA, and DSC. Nanofibers in the range of 100-200 nm were produced with an optimum porosity of 60%. The instrumental analyses confirm the physical interaction between collagen and PCL. Electrospinning of collagen in an environmentally benign solvent has been carried out and its usage in tissue engineering is being investigated by our research group.Correspondence to: A. Gnanamani (gnanamani3@gmail. com) and V. R. Giridev (Giridev vrgiridev@yahoo.com).

This paper discusses the compression creep behaviour of jute-polypropylene blended needle-punched nonwoven. It is essential to know the compression creep behaviour of the needle-punched fabrics too, because of their various applications like geotextiles and carpets. Needle-punched fabric samples were prepared based on the three factors, three levels Box Behnken design of experiment to study the individual as well as interaction effects of process parameters of fabric weight, needling density and blend proportion of jute and polypropylene fibre blend on fabric thickness and compression creep. This study reveals that the initial thickness of fabric decreases prominently with the increase in needling density at low fabric weight and has hardly any effect at high fabric weight (450 g/m 2 ). However, around 43% increase in fabric thickness occurs at high jute content level (60%). At low fabric weight, the effect of the needling density on compression creep is highly prominent when polypropylene content is more than 50% in the blend. However, its effect is negligible when jute content is higher than 50% in the blend. The creep initially decreases with the increase in fabric weight up to a certain limit and thereafter it increases. The minimum value of compression creep of around 14% is obtained at 375 g/m 2 fabric weight with 150 punches/cm 2 needling density at the level of 60% jute content.

The effect of fabric weight, needling density, and blend proportion of jute and polypropylene fibers on water absorbency, fabric thickness, and fabric density has been studied. Box and Behnken experimental design has been used for preparation of needle-punched nonwoven fabric samples. Cluster analysis has been used to study the grouping behavior of the variables. Water absorbency increases with the increase in jute content. Water absorbency decreases with the increase in fabric weight and needling density. Highest water absorbency (720%) of the fabric can be obtained at 60% jute content level with lower needling density and lower fabric weight. The fabric thickness increases with the increase in jute content. At higher level of jute content, with the increase in needling density, the fabric thickness shows decrease in trend. At higher level of fabric weight and higher needling density, with the increase in jute content, the fabric thickness shows a decrease in trend. Maximum fabric density can be obtained at higher fabric weight (450 g/m 2 ), higher jute content (60%) and higher needling density (350 punches/cm 2 ) levels. The influence of fabric weight, needling density, and blend proportion of polypropylene and jute as independent variables on the cluster of fabric thickness and water absorbency is very high as evidence from the Euclidean distances.

The surface resistivity and shear characteristics of the polyaniline/ polyester fabrics produced by varying the number of coatings with different fabric structures were studied. With increase in number of coatings, the resistivity of the fabric decreases. The plain woven fabric gives higher surface resistivity than twill and satin weaves. Shear rigidity of twill and satin fabrics are lower than that of plain woven fabrics.

The effect of fabric parameters such as type of weave and pick density on electrical surface resistivity of polyaniline coated fabric was studied. The fabric structure greatly influences the fabric electrical resistivity. Among the samples tested the twill structure with high picks per inch shows lower surface resistivity. The plain structure which has more interlacement points shows higher resistivity.