چاپ پلاريزان با استفاده از جوهر پلي وينيل الكل/ نانوكريستال سلولز: تعيين اثرات غلظت جوهر و سرعت تبخير حلال

Polarizing printing using a polyvinyl alcohol/cellulose nanocrystal ink: Finding the effects of ink concentration and solvent evaporation rate

ﺳﺎﺑﻘﻪ و ﻫﺪف: اﻣﺮوزه، ﻣﻄﺎﻟﻌﻪ ﭘﯿﺮاﻣﻮن ﻣﻬﻨﺪﺳﯽ ﺧﻮدآراﯾﯽ ﻧﺎﻧﻮﮐﺮﯾﺴﺘﺎلﻫﺎي ﺳﻠﻮﻟﺰي درون ﺑﺴﺘﺮﻫﺎي ﭘﻠﯿﻤﺮي، ﺑﺎ ﻫﺪف ﮔﺴﺘﺮش داﻣﻨﻪ ﮐﺎرﺑﺮدي اﯾﻦ ﻧﺎﻧﻮﺳﺎﺧﺘﺎرﻫﺎي زﯾﺴﺘﯽ، ﺑﻪ ﯾﮑﯽ از ﻣﻮﺿﻮﻋﺎت داغ ﺗﺤﻘﯿﻘﺎﺗﯽ ﺑﺪل ﺷﺪه اﺳﺖ. ﺑﻪﺗﺎزﮔﯽ، ﭘﮋوﻫﺸﮕﺮان روﺷﯽ ﻣﺒﺘﻨﯽ ﺑﺮ ﺑﻬﺮهﮔﯿﺮي از ﮔﺸﺘﺎور ﮐﺸﺶ ﺳﻄﺢ )STT( را ﺑﻪ ﻣﻨﻈﻮر ﮐﻨﺘﺮل ﺧﻮدآراﯾﯽ ﻧﺎﻧﻮﮐﺮﯾﺴﺘﺎل ﻫﺎي ﺳﻠﻮﻟﺰي )CNC( درون ﻣﺤﻠﻮلﻫﺎي ﭘﻠﯿﻤﺮي ﻣﻌﺮﻓﯽ ﻧﻤﻮدﻧﺪ ﮐﻪ اﻣﮑﺎن ﭼﺎپ دوﺷﮑﺴﺘﯽ ﻧﺎﻧﻮﮐﺎﻣﭙﻮزﯾﺘﯽ را ﻓﺮاﻫﻢ ﻣﯽﻧﻤﺎﯾﺪ. در اﯾﻦ ﻣﻘﺎﻟﻪ، ﺗﺄﺛﯿﺮ ﺳﺮﻋﺖ ﺗﺒﺨﯿﺮ ﺣﻼل و ﻏﻠﻈﺖ ﻣﺤﻠﻮل ﭘﻠﯽوﯾﻨﯿﻞاﻟﮑﻞ )PVA(/ ﻧﺎﻧﻮﮐﺮﯾﺴﺘﺎل ﺳﻠﻮﻟﺰ ﺑﻪ ﻋﻨﻮان ﺟﻮﻫﺮ ﭼﺎپ ﭘﻼرﯾﺰان، ﺑﺮ ﮐﯿﻔﯿﺖ ﭼﺎپ ﺳﻪﺑﻌﺪي ﻧﺎﻧﻮﮐﺎﻣﭙﻮزﯾﺘﯽ ﺣﺎﺻﻞ ﺑﺮرﺳﯽ ﺷﺪه اﺳﺖ. ﻣﻮاد و روش ﻫﺎ: ﻣﺤﻠﻮلﻫﺎي آﺑﯽ ﭘﻠﯽوﯾﻨﯿﻞاﻟﮑﻞ )PVA( در 3 ﺳﻄﺢ ﻏﻠﻈﺖ 2/5، 5 و 10 درﺻﺪ، ﺣﺎوي 5 درﺻﺪ وزﻧﯽ ﻧﺎﻧﻮﮐﺮﯾﺴﺘﺎل ﺳﻠﻮﻟﺰي اﺳﺘﺨﺮاج ﺷﺪه از اﻟﯿﺎف ﭘﻨﺒﻪ، ﺑﻪ ﻋﻨﻮان ﺟﻮﻫﺮ ﭼﺎپ ﺗﻬﯿﻪ ﺷﺪﻧﺪ. ﺟﻬﺖ ﭼﺎپ ﻓﯿﻠﻢ ﻫﺎي ﻧﺎﻧﻮﮐﺎﻣﭙﻮزﯾﺘﯽ ﻧﻬﺎﯾﯽ، ﻗﺎﻟﺐرﯾﺰي ﻣﺤﻠﻮل ﺟﻮﻫﺮ ﺑﺮ روي ﺑﺴﺘﺮ ﻣﺴﯽ داراي ﻧﻘﻮش ﺑﺮﺟﺴﺘﻪ اﻧﺠﺎم ﺷﺪ. ﺑﺎ ﻫﺪف ﮐﻨﺘﺮل ﺳﺮﻋﺖ ﺧﺮوج ﺣﻼل، از دو ﻧﻮع آون ﻣﺘﺪاول و آون ﺧﻼء اﺳﺘﻔﺎده ﺷﺪ. ﮐﯿﻔﯿﺖ ﺟﻬﺖﯾﺎﻓﺘﮕﯽ اﺟﺰاي ﺟﻮﻫﺮ و ﭼﺎپ ﭘﻼرﯾﺰان، ﺑﺎ ﻣﯿﮑﺮوﺳﮑﻮپ ﻧﻮري ﭘﻼرﯾﺰان و ﻧﺮم اﻓﺰار ﺗﺤﻠﯿﻞﮔﺮ ﺗﺼﻮﯾﺮ ارزﯾﺎﺑﯽ و ﮐﻤﯽﺳﺎزي ﺷﺪ. ﯾﺎﻓﺘﻪ ﻫﺎ: ﺗﺤﻠﯿﻞ ﺗﺼﺎوﯾﺮ ﻣﯿﮑﺮوﺳﮑﻮﭘﯽ ﻧﺸﺎن داد ﮐﻪ ﺑﺎ اﻓﺰاﯾﺶ ﻧﺴﺒﺖ ﻓﺎز ﺣﺎﻣﻞ PVA در ﺗﺮﮐﯿﺐ ﺟﻮﻫﺮ، ﮔﺮان روي ﺟﻮﻫﺮ ﺑﻪ ﻣﯿﺰان ﻗﺎﺑﻞ ﺗﻮﺟﻬﯽ اﻓﺰاﯾﺶ ﯾﺎﻓﺖ و ﺑﺎ اﻓﺰودن ﻧﺎﻧﻮذرات CNC ﺑﻪ ﺗﺮﮐﯿﺐ ﺑﻪ ﺻﻮرت ﻣﻌﻨﺎداري از ﺷﺪت اﻓﺰاﯾﺶ ﮔﺮان روي ﮐﺎﺳﺘﻪ ﺷﺪ. در ارزﯾﺎﺑﯽ ﮐﯿﻔﯿﺖ ﭼﺎپ از ﻣﻘﺎﯾﺴﻪ ﻣﻘﺎدﯾﺮ ﺳﻪ ﺷﺎﺧﺺ ﺷﺎﺧﺺ ﺗﺒﺎﯾﻦ رﻧﮓ ﻫﺎي ﺗﺪاﺧﻠﯽ )ICC(، ﺷﺎﺧﺺ ﭘﯿﺮوي از اﻟﮕﻮ )PMI(، ﺷﺎﺧﺺ ﺗﻘﺎرن ﻧﻘﺶ )PSI( اﺳﺘﻔﺎده ﺷﺪ. اﻓﺰاﯾﺶ ﻏﻠﻈﺖ ﺟﻮﻫﺮ در ﻧﺘﯿﺠﻪ اﻓﺰاﯾﺶ ﺳﻬﻢ ﻓﺎز ﺣﺎﻣﻞ PVA ﻣﻮﺟﺐ اﻓﺰاﯾﺶ ﺷﺎﺧﺺ ICC ﮔﺮدﯾﺪ و ﺗﺄﺛﯿﺮ اﯾﻦ ﻋﺎﻣﻞ ﺑﺮ دو ﺷﺎﺧﺺ PMI و PSI اﻟﮕﻮي ﻣﺸﺎﺑﻬﯽ را ﻧﺸﺎن داد؛ ﺑﻪﻃﻮريﮐﻪ ﺑﯿﺶ ﺗﺮﯾﻦ و ﮐﻢ ﺗﺮﯾﻦ ﻣﻘﺎدﯾﺮ ﺑﻪ دﺳﺖ آﻣﺪه ﺑﺮاي ﺟﻮﻫﺮ ﺳﻪﺟﺰﺋﯽ، ﺑﻪﺗﺮﺗﯿﺐ، در ﻏﻠﻈﺖ 10 و 5 درﺻﺪ PVA ﺑﻪدﺳﺖ آﻣﺪ. اﻓﺰاﯾﺶ ﺳﺮﻋﺖ ﺧﺮوج ﻓﺎز ﺣﻼل، ﺗﺄﺛﯿﺮ ﻣﻌﻨﺎداري را ﺑﺮ ﺗﻐﯿﯿﺮات ﺷﺎﺧﺺ ICC ﻧﺸﺎن ﻧﺪاد درﺣﺎﻟﯽ ﮐﻪ ﻣﻘﺎدﯾﺮ دو ﺷﺎﺧﺺ PMI و PSI را ﺑﻪﺻﻮرت ﻣﻌﻨﺎدار ﻣﺘﺄﺛﺮ ﻧﻤﻮد و ﻣﻮﺟﺐ ﮐﺎﻫﺶ ﮐﯿﻔﯿﺖ ﭼﺎپ ﮔﺮدﯾﺪ. ﻧﺘﯿﺠﻪ ﮔﯿﺮي: ﺑﻪﻃﻮر ﺧﻼﺻﻪ، ﺑﺮ اﺳﺎس ﯾﺎﻓﺘﻪﻫﺎي ﭘﮋوﻫﺶ ﺣﺎﺿﺮ، ﻣﯽﺗﻮان ﭼﻨﯿﻦ ﺑﯿﺎن ﻧﻤﻮد ﮐﻪ در ﻓﺮاﯾﻨﺪ ﭼﺎپ ﭘﻼرﯾﺰان، اﺳﺘﻔﺎده از ﺟﻮﻫﺮ ﭼﺎپ ﺳﻪﺟﺰﺋﯽ ﻧﺴﺒﺖ ﺑﻪ ﻧﻮع دوﺟﺰﺋﯽ در اوﻟﻮﯾﺖ ﻗﺮار دارد. ﻫﻢ ﭼﻨﯿﻦ ﮐﺎﻫﺶ ﺳﺮﻋﺖ ﺧﺮوج ﺣﻼل ﻣﯽ ﺗﻮاﻧﺪ ﺗﺄﺛﯿﺮ ﻗﺎﺑﻞ ﻣﻼﺣﻈﻪ اي ﺑﺮ ﮐﯿﻔﯿﺖ ﭼﺎپ داﺷﺘﻪ ﺑﺎﺷﺪ. ﻣﺘﻨﺎﺳﺐ ﺑﺎ ﺗﺮﮐﯿﺐ ﺟﻮﻫﺮ اﺳﺘﻔﺎده ﺷﺪه در اﯾﻦ ﻣﻄﺎﻟﻌﻪ، ﺟﻬﺖ دﺳﺘﯿﺎﺑﯽ ﺑﻪ ﮐﯿﻔﯿﺖ ﭼﺎپ ﻣﻄﻠﻮب، ﺳﻄﺢ ﻏﻠﻈﺖ 5 درﺻﺪ ﺑﺮاي ﻓﺎز ﺣﺎﻣﻞ ﻗﺎﺑﻞ ﺗﻮﺻﯿﻪ ﻣﯽ ﺑﺎﺷﺪ

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