Chemical Engineering / Kimya Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/14
Browse
3 results
Search Results
Now showing 1 - 3 of 3
Conference Object Hidrofobik İlaç Taşıyıcısı Olarak Akrilik Yıldız Blok Kopolimerler(Institute of Electrical and Electronics Engineers Inc., 2009) Genç, Gözde; Batıgün, Ayşegül; Bayraktar, Oğuz; Altıntaş, Özcan; Tunca, Ümit; Hizal, GürkanAmphiphilic poly(methyl methacrylate)-b-poly(acrylic acid) (PMMA-b-PAA) copolymers with 4 and 6 arms were synthesized by Atomic Transfer Radical Polymerization (ATRP). The polymers were characterized by GPC, H-NMR and FTIR analysis. Polymer samples synthesized at various molecular weights between 18-80 kDa were investigated in terms of maximum loading capacity and critical micelle concentration by fluorescence spectroscopy. 4 arm PMMA-b-PAA (MW 30 kDa) was loaded with hydrophobic model drug indomethacin with an extremely high drug loading efficiency (22.5% drug content). Drug loaded polymer formed a stable and biodegradable complex in aqueous medium.Article Citation - WoS: 5Citation - Scopus: 8A Research on the Production of Silk Sericin Powders by Using Spray Drying Method(Ege Üniversitesi, 2009) Genç, Gözde; Bayraktar, Oğuz; Başal, GüldemetSericin protein is usually discarded as a waste in silk industry. Production of silk sericin powders, which can be incorporated into fibers used in textile industry, by spray drying method will enable value-added utilization of waste sericin. in this study aqueous sericin solutions were used as raw material for the production of dry powders using a lab-scale spray dryer. A linear regression analyses were employed, in addition to experimental design at two levels with three factors for the analysis of three responses: moisture content, particle type and agglomeration degree. The process factors were the drying air temperature (120°C and 160°C), the feed rate (1.25x10-4 and 2.5x10-4 dms -), and the concentration of sericin solutions of 10% and 30% (w/w) fed to the spray dryer. The three responses were analyzed statistically to determine the effective parameters and it was concluded that moisture content depended on three factors-drying air temperature being the dominant parameter. Particle size and shape depended mainly on feed rate and agglomeration depended on the moisture content of the product.Article Citation - WoS: 8Citation - Scopus: 10Moisture Sorption and Thermal Characteristics of Polyaramide Blend Fabrics(John Wiley and Sons Inc., 2006) Genç, Gözde; Alp, Burcu; Balköse, Devrim; Ülkü, Semra; Cireli, AysunFour types of fabrics woven from various polyaramid fibers of Nomex and Kevlar blends were characterized by morphology, XRD, elemental analysis, thermal analysis, and moisture adsorption isotherms. The blends consisted of Polybenzimidazole/ Kevlar blend (40% FBI and 60% Kevlar®), Nomex Delta A (blend of 60% Kevlar and 40% Nomex®), Nomex Delta T (blend of 75% Nomex, 23% Kevlar, and 2% P140 antistatic fiber), and Nomex III (fabric with a 95/5 blend of Nomex and Kevlar) containing 1% steel fiber. TGA and DTG curves have been compared to evaluate thermal behavior of the FBI, Kevlar, and Nomex blends and the resuls were correlated with the moisture sorption data. The data were also compared with fiber morphologies provided by SEM and crystallinities derived from XRD diffrac tograms. Moisture adsorption isotherms were correlated with a number of empirical models, including Nernst, Freundlich, Handersen, Iglesias-Chirife, and with the models having a theoretical background such as Langmuir, BET, GAB, and Hüttig. The linear regression models were statistically analyzed to obtain the best fitting model that explains the sorption profiles of the samples and theoretical monolayer moisture capacities of Nomex and Kevlar blends were calculated by using Hüttig isotherms.