تاثير نانوالياف سلولز بر خواص نوري و مكانيكي آثار كاغذي تاريخي

Influence of the cellulose nanofibers on optical and mechanical strength of the historical paper relics

ﻫﺪف اﯾﻦ ﭘﮋوﻫﺶ، ارزﯾﺎﺑﯽ ﺗﺄﺛﯿﺮ ﻣﺎده ﻧﺎﻧﻮاﻟﯿﺎف ﺳﻠﻮﻟﺰ و اﺳﺘﻔﺎده از آن ﺑﻪﻋﻨﻮان اﺳﺘﺤﮑﺎمﺑﺨﺶ ﺟﻬﺖ ﺑﺎزﮔﺮداﻧﺪن ﻣﻘﺎوﻣﺖ ﮐﺸﺸﯽ و اﺳﺘﺤﮑﺎم ﺑﻪ آﺛﺎر ﮐﺎﻏﺬي ﺗﺎرﯾﺨﯽ اﺳﺖ. روش اﻧﺠﺎم ﭘﮋوﻫﺶ ﺗﺤﻠﯿﻠﯽ- ﻣﻘﺎﯾﺴﻪاي و ﺷﯿﻮه ﮔﺮدآوري دادهﻫﺎ از ﻃﺮﯾﻖ آزﻣﺎﯾﺶﻫﺎي ﻣﺮﺗﺒﻂ ﺑﺎ ﻣﻮﺿﻮع ﭘﮋوﻫﺶ ﻫﻤﭽﻮن pH ﺳﻨﺠﯽ، رﻧﮓﺳﻨﺠﯽ و اﻧﺪازه-ﮔﯿﺮي ﻣﻘﺎوﻣﺖ ﮐﺸﺸﯽ ﻧﻤﻮﻧﻪﻫﺎ ﺑﻮده اﺳﺖ. در اﯾﻦ ﭘﮋوﻫﺶ ﺗﯿﻤﺎر ﻧﺎﻧﻮ اﻟﯿﺎف ﺳﻠﻮﻟﺰ ﺑﺎ درﺻﺪﻫﺎي وزﻧﯽ 1 ،0/5 و 2 درﺻﺪ، ﺑﻪﺻﻮرت ﺳﻮﺳﭙﺎﻧﺴﯿﻮن ﺑﺎ آب ﺗﻬﯿﻪ ﺷﺪ و ﺟﻬﺖ اﺳﺘﺤﮑﺎمﺑﺨﺸﯽ ﻧﻤﻮﻧﻪﻫﺎي ﮐﺎﻏﺬ، ﻣﻮرد اﺳﺘﻔﺎده ﻗﺮار ﮔﺮﻓﺖ. ﺗﯿﻤﺎر ﺣﺎﺻﻞ روي ﻧﻤﻮﻧﻪ-ﻫﺎي ﮐﺎﻏﺬي ﺳﻪ ﺑﺎر ﺑﻪوﺳﯿﻠﻪ اﺳﭙﺮي دﺳﺘﯽ ﺑﻪ ﻣﻘﺪار 3 ﻣﯿﻠﯽﻟﯿﺘﺮ اﺳﭙﺮي ﺷﺪ و ﺳﭙﺲ ﻧﻤﻮﻧﻪﻫﺎي ﺗﯿﻤﺎر ﺷﺪه ﺑﺮ اﺳﺎس اﺳﺘﺎﻧﺪاردASTM D776-92، در دﻣﺎي 105 درﺟﻪ ﺳﺎﻧﺘﯽﮔﺮاد ﺑﻪ ﻣﺪت 144 ﺳﺎﻋﺖ ﺗﺤﺖ ﮐﻬﻨﻪﺳﺎزي ﺣﺮارﺗﯽ ﻗﺮار ﮔﺮﻓﺘﻨﺪ. در ﻣﺮﺣﻠﻪ ﺑﻌﺪ ﺗﻐﯿﯿﺮات pH، رﻧﮓ و ﻣﻘﺎوﻣﺖ ﮐﺸﺸﯽ ﻧﻤﻮﻧﻪﻫﺎ ﻣﻮرد ﺑﺮرﺳﯽ ﻗﺮار ﮔﺮﻓﺖ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ ﻣﻘﺪار pH ﻧﻤﻮﻧﻪﻫﺎ ﭘﺲ از ﺗﯿﻤﺎر در ﻣﺤﺪوده 6/98 ﺗﺎ 7/17 و ﺑﻌﺪ از ﻋﻤﻞ ﮐﻬﻨﻪﺳﺎزي ﻧﯿﺰ pH ﻧﻤﻮﻧﻪﻫﺎ در ﻣﺤﺪوده ﻧﺰدﯾﮏ ﺑﻪ ﻗﻠﯿﺎﯾﯽ 6/85 ﺗﺎ 7/11 ﻗﺮار ﮔﺮﻓﺘﻪ اﺳﺖ. ﺷﺎﺧﺺ ﻣﻘﺎوﻣﺖ ﮐﺸﺸﯽ ﻧﻤﻮﻧﻪﻫﺎ ﻧﯿﺰ در ﻫﺮ 3 ﻏﻠﻈﺖ ﭘﺲ از ﺗﯿﻤﺎر اﻓﺰاﯾﺶ ﭘﯿﺪا ﮐﺮده اﺳﺖ اﻣﺎ ﭘﺲ از ﮐﻬﻨﻪﺳﺎزي ﺷﺎﺧﺺ ﻣﻘﺎوﻣﺖ ﮐﺸﺸﯽ ﻧﻤﻮﻧﻪﻫﺎ ﻧﺴﺒﺖ ﺑﻪ ﻣﺮﺣﻠﻪ ﻗﺒﻞ ﮐﺎﻫﺶﯾﺎﻓﺘﻪ اﺳﺖ. ﺑﯿﺸﺘﺮﯾﻦ ﻣﻘﺪار ﻣﻘﺎوﻣﺖ ﮐﺸﺸﯽ در ﻣﺮﺣﻠﻪ ﺑﻌﺪ از ﺗﯿﻤﺎر ﻣﺮﺑﻮط ﺑﻪ ﻧﻤﻮﻧﻪﻫﺎي ﺑﺎ ﺗﯿﻤﺎر 2 درﺻﺪ ﺑﻪاﻧﺪازه 28/2 و ﭘﺲ از ﮐﻬﻨﻪﺳﺎزي ﺑﻪاﻧﺪازه 26/3 ﻧﯿﻮﺗﻦ ﻣﺘﺮ ﺑﺮ ﮔﺮم اﺳﺖ.

The purpose of this study was to evaluate the effect of cellulose nanofibers and its use as a strength enhancer to restore tensile strength and durability to historical paper relics. This research was conducted by analytical comparisons method and samples were collected by experiments related to research topics such as pH measurement, calorimetric and the measurement of tensile strength of the samples. In this study, treatment of cellulose nanofibers with weight percentages of 0.5, 1 and 2%, was prepared as a suspension with water and used to consolidation of the paper samples. The treatment was sprayed three times by 3.5 ml using spray can, then the treatment samples were thermally aged for 144 h at D776-92 ASTM, at a temperature of 105 °C. Next, changes of pH, color and tensile strength of the specimens were investigated. Results showed that the pH of the samples after treatment ranged from 6.98 to 7.17 and after the aging, pH of the samples was in the near alkaline range of 6.85 to 7.11. The tensile strength index of the samples also increased in all 3 concentrations after treatment, however after aging, the tensile strength index of the samples decreased compared with the previous phase. The highest tensile strength after treatment was observed in samples with 2% treatment at 28.2 and after aging 26. 3 Nm/g per meter.