بررسی خصوصیات رئولوژیکی غلظت های متفاوت ژل نانوفیبر تهیه شده از تفالۀ گوجه فرنگی

In the current study, the nanofiber gel of tomato pomace was prepared using a super disk grinder device available at Nano Novin Polymer Co., Iran. Three different concentrations (2, 4 and 6%) of the gel prepared and rheological tests including amplitude sweep, frequency sweep, temperature sweep, and flow behavior were done. DLS results showed that the average diameter of tomato nano-gel was around 38 nm. The power law model was chosen as the best model for describing flow behavior data. All samples showed a shear-thinning behavior that viscosity decreased with increasing shear rate. A hysteresis loop was observed in all samples which confirmed the thixotropic characteristic of gels. Based on amplitude sweep data, elastic modulus (G') was higher than viscous modulus (G"), in addition, crossover points of all gels showed that the flowability decreased with increasing concentrations. Based on frequency data, G' in all concentrations was higher than G" and both parameters increased with increasing concentration from 2 to 6%. In lower frequencies, all gels showed solid-like behavior while G' and G" increased with increasing frequency indicating the weakening of the gel network. G' and G" gradually decreased with increasing temperature from 5 to 50 ºC which confirmed that all gels were weakened at high temperatures, but in the cooling cycle, all gels recovered their structures and no remarkable hysteresis was observed. [ABSTRACT FROM AUTHOR]