Fabrication of Woven Honeycomb Structures for Advanced Composites

A honeycomb woven fabric was designed and produced on a sampling loom. After weaving cells in the fabric were opened by polytetrafluoroethylene (PTFE) sticks and an epoxy resin was applied to fabric. For comparison half of the fabric sample was impregnated with resin without opening the cells. Resulting fabric samples were subjected to low-velocity impact test by using drop weight impact testing machine, CEAST Fractovis Plus – 7526.000. To evaluate the impact behaviour of the samples the contact force, contact time, deflection, and absorbed energy values were recorded by data acquisition system (DAS). The energy absorbed by honeycomb structure was around 7 Joule. The energy absorbed by flat sample, on the other hand, was too low and out of the detection range of the testing equipment

ADSORPTION/DESORPTION AND BIOFUNCTIONAL PROPERTIES OF OLEUROPEIN LOADED ON DIFFERENT TYPES OF SILK FIBROIN MATRICES

WOS: 000405119400013The objective of this study was to investigate the adsorption/desorption behavior of oleuropein on different types of silk fibroin matrices including silk fibroin microfibers (MF), regenerated silk fibroin (RSF), and silk fibroin nanofibers (NF). Nanofibers with an average diameter of ranging between 24 and 326 nm were successfully prepared using the electrospinning technique. The effects of the silk fibroin concentration, the voltage applied and the distance between needle tip and collector plate on the morphology of the NF were investigated. The adsorption capacities of MF, RSF and NF were determined as 104.92, 163.07 and 228.34 mg oleuropein per gram of material, respectively. The percentage of initially adsorbed oleuropein that was desorbed was 86.08, 91.29 and 96.67% for MF, RSF and NF, respectively. NF and RSF discs loaded with oleuropein were subjected to disc diffusion assays to determine their antibacterial activity against test microorganisms Staphylococcus epidermidis (Gram +) and Escherichia coli (Gram -). The results showed that both biomaterials possessed antibacterial properties after loading with oleuropein. Wound scratch assays using oleuropein released from NF revealed an enhancement of cell migration, indicating a wound healing property of the material. In conclusion, the NF can be utilized as a biofunctional polymeric material with better performance for the adsorption and desorption of oleuropein compared with MF and RSF.Natural Products Research Development Unit (NPRDU) located in Technology Development Zone [DUA01/2010]The support (DUA01/2010) from Natural Products Research Development Unit (NPRDU) located in Technology Development Zone for the thesis study of Mr. Ali Bora Balta is gratefully acknowledged

Fabrication of Woven Honeycomb Structures for Advanced Composites

A honeycomb woven fabric was designed and produced on a sampling loom. After weaving cells in the fabric were opened by polytetrafluoroethylene (PTFE) sticks and an epoxy resin was applied to fabric. For comparison half of the fabric sample was impregnated with resin without opening the cells. Resulting fabric samples were subjected to low-velocity impact test by using drop weight impact testing machine, CEAST Fractovis Plus – 7526.000. To evaluate the impact behaviour of the samples the contact force, contact time, deflection, and absorbed energy values were recorded by data acquisition system (DAS). The energy absorbed by honeycomb structure was around 7 Joule. The energy absorbed by flat sample, on the other hand, was too low and out of the detection range of the testing equipment

Properties of n-Eicosane-Loaded Silk Fibroin-Chitosan Microcapsules

WOS: 000291438200003PCM microcapsules containing n-eicosane were prepared by complex coacervation of silk fibroin (SF) and chitosan (CHI). Chemical characterization of microcapsules was carried out using Fourier-transform infrared (FT-IR) spectroscopy. Thermal properties and thermal stability of microencapsulated n-eicosane were determined by differential scanning calorimetry (DSC) and thermal gravimetric analysis TGA). FTIR spectra confirmed the encapsulation of n-eicosane within the microcapsules. Results from thermal analyses showed that microcapsules consisted of an average of 45.7 wt % n-eicosane, and had a thermal energy storage and release capacity of about 93.04 J/g and 89.68 J/g, respectively. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121:1885-1889, 2011Ege University Research FoundationEge University [08-MUH-042]Ege University Research Foundation; contract grant number: 08-MUH-042

Bioactive Sheath/Core Nanofibers Containing Olive Leaf Extract

WOS: 000369165100005PubMed ID: 26626545This study aimed at producing silk fibroin (SF)/hyaluronic acid (HA) and olive leaf extract (OLE) nanofibers with sheath/core morphology by coaxial electrospinning method, determining their antimicrobial properties, and examining release profiles of OLE from these coaxial nanofibers. Optimum electrospinning process and solution parameters were determined to obtain uniform and bead-free coaxial nanofibers. Scanning electron microscopy and transmission electron microscopy (TEM) were used to characterize the morphology of the nanofibers. The antimicrobial activities of nanofibers were tested according to AATCC test method 100. Total phenolic content and total antioxidant activity were tested using in vitro batch release system. The quality and quantity of released components of OLE were determined by high-performance liquid chromatography. The changes in nanofibers were examined by Fourier-transform infrared spectroscopy. Uniform and bead-free nanofibers were produced successfully. TEM images confirmed the coaxial structure. OLE-loaded nanofibers demonstrated almost perfect antibacterial activities against both of gram-negative and gram-positive bacteria. Antifungal activity against C. albicans was rather poor. After a release period of 1 month, it was observed that similar to 70-95% of the OLE was released from nanofibers and it was still bioactive. Overall results indicate that the resultant shell/core nanofibers have a great potential to be used as biomaterials. (C) 2015 Wiley Periodicals, Inc.DUAG Natural ProductsThe authors gratefully acknowledge the DUAG Natural Products for their support

Functionalization of Woven Fabrics with PBT Yarns

Ertekin, Mustafa/0000-0002-5492-7982; Demsar, Andrej/0000-0001-5569-4554WOS:000611488200001PubMed: 33466798Elasticity and recovery are important for clothing comfort, especially in the manufacture of apparel and sportswear. Recently, yarns containing PBT (polybutylene terephthalate), which are able to develop good elastic properties with high recovery after a finishing process (e.g., thermal treatment), have been used for this purpose. The aim of this work is to give a comprehensive overview of the use of PBT yarns in woven structure, with the aim of improving the elastic properties of cotton-like fabrics. The experimental part was divided into three main sequences to investigate the fabric properties (physical, elastic, UPF, comfort) influenced by (1) PBT-containing yarn structure, (2) weave and fabric structure (basic weaves and complex weaves) with PBT in weft direction, and (3) processing sequence-thermal treatment of PBT yarns or fabrics after weaving. According to the results, PBT-containing yarns have great potential for the production of lightweight elastic fabrics. The advantages of improving the elastic properties of fabrics by incorporating a relatively small amount of PBT yarns into the fabric only in certain areas, thereby minimally affecting the production costs, are demonstrated by a product with partially elastic areas obtained after thermal treatment.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK); Slovenian Research Agency (ARRS)Slovenian Research Agency - Slovenia [BI-TR/15-17-006]; Slovenian Research AgencySlovenian Research Agency - Slovenia [P2-0213]This research was funded by Scientific and Technological Research Council of Turkey (TUB.ITAK) and Slovenian Research Agency (ARRS) within bilateral project (Project number: BI-TR/15-17-006). This work was cofounded by the Slovenian Research Agency (Program P2-0213 Textiles and Ecology)