نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 دانشجوی دکتری، گروه تکنولوژی و مهندسی چوب، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران،
2 دانشیار، گروه تکنولوژی و مهندسی چوب، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران،
3 دانشیار ، گروه تکنولوژی و مهندسی چوب، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران،
4 دانشیار ، آزمایشگاه نانومواد تجدیدپذیر، دانشگاه مین، ایالات متحده آمریکا
چکیده
کلیدواژه‌ها
عنوان مقاله [English]
نویسندگان [English]
Abstract
Background and objectives:
Self-assembly engineering of cellulose nanocrystals in polymer substrates to expand the application range of these bio-nanostructures has become one of the hot topics of research. Mashkour et al. (2013 and 2019) introduced a method based on surface tension torque (STT) to control cellulose nanocrystals' self-assembly in polymer solutions to print birefringent nanocomposites. In this paper, the effect of solvent evaporation rate and concentration of polyvinyl alcohol/cellulose nanocrystal solution as polarizing printing ink on the quality of 3D nanocomposite printing was investigated.
Materials and methods:
Aqueous polyvinyl alcohol (PVA) solutions were prepared at three concentrations of 2.5, 5, and 10 percent, containing 5 percent of cellulose nanocrystal (CNC) by weight extracted from cotton fibers as printing ink. An embossed copper mold was used for the printing of polarizing nanocomposite films. The conventional oven and vacuum oven were used to regulate the rate of ink solvent evaporation. Evaluation and comparison of polarizing print quality were performed by microscopic imaging and quantitative analysis of the resulting micrographs.
Results:
Analysis of microscopic images revealed that by increasing the ink carrier (PVA) ratio in the ink formulation, the ink viscosity increased significantly, whereas by adding CNC nanoparticles to the composition, the increase in viscosity was significantly reduced. Three indicators were defined and used to assess and compare the quality of printing: Interference Color Contrast (ICC) Index, Pattern Match Index (PMI) and Pattern Symmetry Index (PSI). The increased concentration of ink due to an increase in the weight fraction of the ink carrier increased the ICC index, and the effect of this factor on the PMI and PSI indices showed a similar pattern; The highest and lowest values of the PMI and PSI for three-component inks were obtained at concentrations of 10% and 5% PVA, respectively. Increasing the solvent phase's evaporation rate did not significantly affect the ICC index, while PMI and PSI values significantly affected and reduced print quality.
Conclusion:
In summary, based on the findings of this study, it can be stated that the use of three-part printing ink takes precedence over two-part printing ink. Reducing the evaporation rate of the solvent phase was also found to have a significant positive effect on print quality. With regard to the ink composition used in this study, a concentration level of 5% is recommended for the ink carrier to achieve the desired print quality.With regard to the ink composition used in this study, a concentration level of 5% is recommended for the ink carrier to achieve the desired print quality.
کلیدواژه‌ها [English]
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