Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - Scopus: 2Film-Formation Property of Vinylidene Chloride-Methyl Methacrylate Copolymer Latex. Ii. Effect of Latex Storage Temperature(2002) Cai,W.D.; Ramesh,N.; Tihminlioglu,F.; Danner,R.P.; Duda,J.L.; Dhaan,A.Changes in the minimum film-formation temperature (MFFT) of 91:9 wt% vinylidene chloride (VDC)-methyl methacrylate (MMA) latex prepared by the seeded batch process during storage at 5, 20, and 40°C were investigated. MFFT of the latex rose the fastest at 20°C. Infrared absorption of fresh and stored latexes and wide-angle X-ray diffraction of powder polymers obtained by lyophilization of fresh and stored latexes indicated a much greater increase in polymer crystallinity during latex storage at 20°C than at 5 and 40°C. Observed increases in MFFT during latex storage correlated with increases in polymer crystallinity. Infrared absorption of polymer stored at 5-60°C in the dry state, such as lyophilized polymer and coating film, indicated that a polymer crystallinity increase was greater during storage at higher temperatures. These results showed that crystallization behavior of 91:9 wt% VDC-MMA copolymer latex differed from that of VDC-MMA copolymer in the dry state.Article Payne Cell Gravimetric Measurements in Polymer-Solvent Systems for Diffusion Coefficients and Isotherm Data(Wiley, 2021) Zielinski, John M.; Garcia, Armando R.; Alsoy Altınkaya, SacideThe discussion focuses on the application of a Payne cell to the measurement of diffusion and solubility coefficients in polymer/solvent systems. Payne cells have, thus far, been used exclusively to measure steady-state permeation rates of solvents. An analytical model has been developed to describe transient gravimetric sorption and desorption measurements performed with a Payne cell. The model has been validated by a complementary numerical simulation and has been applied to evaluate diffusion and solubility coefficients in two different toluene-silicone rubber systems. The data measured using the Payne cell are found to compare very well with diffusion coefficient and isotherm data measured by traditional gravimetric sorption experiments.Article Citation - WoS: 4Citation - Scopus: 4Color-Tunable All-Inorganic Cspbbr3 Perovskites Nanoplatelet Films for Photovoltaic Devices(American Chemical Society, 2019) Özcan, Mehmet; Özen, Sercan; Topçu, Gökhan; Demir, Mustafa Muammer; Şahin, HasanHerein, we demonstrate a novel coating approach to fabricate CsPbBr3 perovskite nanoplatelet film with heat-free process via electrospraying from precursor solution. A detailed study is carried out to determine the effect of various parameters such as ligand concentration, electric field, flow rate, etc. on the optical properties. By controlling the volume ratios of the oleylamine (OAm) and oleic acid (OA), the coalescing and thickness of the resulting nanoplatelets can be readily tuned that results in control over emission in the range of 100 nm without any antisolvent crystallization or heating processes. The varying electrical field and flow rate was found as inefficient on the emission characteristics of the films. In addition, the crystal films were obtained under ambient conditions on the ITO coated glass surfaces as in the desired pattern. As a result, we demonstrated a facile and reproducible way of synthesizing and coating of CsPbBr3 perovskite nanoplatelets which is suitable for large-scale production. In this method, the ability of tuning the degree of quantum confinement for perovskite nanoplatelets is promising approach for the one-step fabrication of crystal films that may enable the use in optoelectronics.Article Citation - WoS: 13Citation - Scopus: 18Effect of Corn-Zein Coating on the Mechanical Properties of Polypropylene Packaging Films(John Wiley and Sons Inc., 2011) Tıhmınlıoğlu, Funda; Atik, İsa Doğan; Özen, BanuIn this study, a novel film structure of corn zein coated on polypropylene (PP) synthetic films for food packaging applications was developed, and the mechanical properties of the resulting coated film, as affected by the coating formulation, were investigated. Composite structures of PP films coated with corn zein were obtained through a simple solvent casting method. Different amounts of corn zein (5 and 15%) were dissolved in 70 and 95% aqueous ethanol solution at 50 C. Solutions of corn zein plasticized with poly(ethylene glycol) and glycerol (GLY) at various levels (20 and 50%) were applied on corona-discharge-treated PP. A statistical analysis based on full factorial design was performed to examine the influence of the coating formulation on the final properties of the corn-zein-coated PP films. A significant (p < 0.05) improvement in the coated film’s mechanical properties was observed compared to those of the uncoated PP. The effect of the plasticization of the coating solutions was also quite significant. In general, GLY provided better improvements in the mechanical properties of the corn-zein-coated PP films. The statistical analysis of the results showed that the corn-zein and plasticizer concentrations and plasticizer type used in the coating formulations were more effective parameters and had significant effects on the mechanical behavior of the coated PP films. In conclusion, corn-zein coatings could have potential as alternatives to conventional synthetic polymers used in composite multilayer structures for food packaging applications.Article Citation - WoS: 11Citation - Scopus: 13Water Vapour Barrier Performance of Corn-Zein Coated Polypropylene (pp) Packaging Films(Springer Verlag, 2008) Atik, İsa Doğan; Özen, Fatma Banu; Tıhmınlıoğlu, FundaThe novel film structure of corn-zein coated on polypropylene (PP) synthetic film for packaging industry was developed to examine the feasibility of resulting coated films as an alternative water barrier performance for food packaging. The effects of coating formulation (solvent, corn-zein, plasticizer concentration and plasticizer type) on final properties of films were observed. Corn-zein is the most important protein of corn and has good film forming property. Composites structures of PP films coated with corn-zein were obtained through a simple solvent casting method. Polyethylene glycol (PEG) and glycerol (GLY) were used as plasticizer to increase film flexibility. Statistical analysis based on full factorial design was performed to observe coating formulation effects. The high water vapour barriers were obtained for films coated with coating formulation consisting of higher amounts of corn-zein plasticized by GLY. The lower glass transition temperatures (T g) of films were obtained by plasticization of films and T g decreased by increasing plasticizer content. The statistical analysis defined the key parameters of coating formulation that had major effects on the final properties of coated PP films as corn-zein, plasticizer concentration and plasticizer type. In conclusion, corn-zein coatings could have potential as an alternative to conventional synthetic polymers used in composite multilayer structures for food packaging applications.Article Citation - WoS: 19Citation - Scopus: 18Predicting Drying in Multiple-Zone Ovens(American Chemical Society, 2001) Alsoy Altınkaya, SacideIn the coating industry, the drying of solvent-coated polymeric films takes place in convected heated dryers, which usually consist of a series of zones. The operating conditions of airflow, solvent partial pressure(s), and temperature at the entrance of each zone are chosen to minimize the drying time while maintaining an acceptable product quality. In this work, the drying behavior of polymer solutions in such oven configurations is predicted from binary and multicomponent drying models. Both models involve coupled heat- and mass-transfer equations that describe the changes in the concentration of each solvent, the temperature, and the thickness of the film throughout the drying. The model equations become highly nonlinear because of the strong and complicated concentration and temperature dependencies of the thermodynamic and transport properties of polymer solutions. These nonlinear equations are solved numerically using the finite difference approximation. The solutions show that multiple-zone ovens can be used to eliminate bubble formation and to minimize the residual solvent content by controlling the operating conditions individually or simultaneously.