Yazarlar

  • MakaleYalnız künye2022Scopus SJRQ1
    Graphene-reinforced novel poly(acetoxystyrene-co-glycidylmethacrylate) composites: Synthesis and optimization of dielectric behaviors using response surface methodology

    Pihtili, Güzin

    In this work, a new copolymer synthesis of Poly(acetoxystyrene-co-glycidylmethacrylate) (P[AOS-co-GMA]) by free radical polymerization (FRP) method is reported. The polymer composites (P[AOS-co-GMA]/graphene), containing different amounts of graphene, were prepared by the solution casting technique. Composites of Poly(acetoxystyrene-co-glycidylmethacrylate) loaded with 2.03 mass%, 5.00 mass%, 7.97 mass%, and 10 mass% graphene. The structure of AOS-GMA systems was characterized by fourier transform infrared, 1H-NMR and scanning electron microscopy. Thermal features were evaluated by the thermogravimetric analysis and differential scanning calorimetry. The aim of this study is to optimize the ε′ (dielectric constant) and ε′′ (dielectric loss factor) of pure polymer and graphene-doped (2.03-5-7.97-10 mass%) P(AOS-co-GMA) composite using response surface methodology. For optimization of the process and creation of the mathematical model, the central composite design package was used. The significance of the process parameters in the model was evaluated by analysis of variance (ANOVA) research. The effects of process parameters, frequency (Hz), voltage (V), and graphene ratio (mass%) on ε′ and ε′′ were examined at ambient temperature. The maximum ε″ value (8.01) was reached at around the 699 Hz frequency and at 11.43 V voltage at the graphene content of 9.82 mass%. The model estimated the maximum value of the ε′′ (0.08) when the frequency was set at 51.20, the voltage was fixed at 1.16 and the graphene content was fixed at 9.97 wt%. The ANOVA results showed that frequency and graphene content were the main model parameters and had a remarkable effect on the dielectric properties. This article presents the development of a new polymeric composite and optimize effect of process parameters, such as frequency (A), voltage (B) and amount of graphene (C).

    AtıfScopus4WoS4OpenAlex4
    ScopusWeb of Scienceİncele
  • MakaleAçık Erişim2019Scopus SJRQ2
    Optimization of microwave apple drying using response surface method; [Yanit yüzey metodu kullanarak mikrodalga ile elma kurutmanin optimizasyonu]

    Yoǧurtçu, Hakan

    In this study, the effects of microwave output power and slice thickness on microwave drying of apple slices were studied by using response surface method (RSM) in a modified domestic microwave oven. For experimental design, the central composite rotatable design approach was used. The values of response variables, effective diffusion coefficient, drying rate constant, color change, Hue angle, total drying time and energy consumption, were determined from the experiments performed under design conditions. It was seen that the obtained second order polynomial equations successfully represent the response variables. The results of analysis of variance (ANOVA) and response surface curves revealed that microwave output power and slice thickness were significantly effective on response variables. The effects of the independent variables on the responses and the significance level of these effects were evaluated statistically and the optimum drying conditions were determined for the aims of min color change, total drying time, energy consumption and max Hue angle. Verification experiments were performed with a maximum of 9.54% error at the recommended optimum test conditions. It has been shown that the response surface method can be successfully applied in the microwave drying of apples.

    AtıfScopus6WoS5OpenAlex3TR Dizin3
    ScopusWeb of ScienceTR Dizinİncele