ﺗﻬﯿﻪ و ﻣﺸﺨﺼﻪ ﯾﺎﺑﯽ ﻧﺎﻧﻮﮐﺎﻣﭙﻮزﯾﺖ ﻧﺎﻧﻮ ﻟﻮﻟﻪ ﮐﺮﺑﻨﯽ- ﺗﯿﺘﺎﻧﺎت ﺑﺎرﯾﻢ/ﺳﯿﻠﯿﮑﺎ ﺑﻪ روش ﺳﻞ- ژل و ﺑﺮرﺳﯽ ﺧﻮاص ﺣﻔﺎﻇﺘﯽ آن در ﺑﺮاﺑﺮ اﻣﻮاج اﻟﮑﺘﺮوﻣﻐﻨﺎﻃﯿﺲ

Sol-Gel Preparation, Characterization and Electromagnetic Interference Shielding of MWCNT-BaTiO3/Silica Nanocomposite

در اﯾﻦ ﭘﮋوﻫﺶ روش ﺳﻞ-ژل ﺟﻬﺖ ﺳﻨﺘﺰ ﻧﺎﻧﻮﮐﺎﻣﭙﻮزﯾﺖ ﻧﺎﻧﻮﻟﻮﻟﻪ ﮐﺮﺑﻨﯽ- ﺗﯿﺘﺎﻧﺎت ﺑﺎرﯾﻢ/ﺳﯿﻠﯿﮑﺎ ﺑﻪ ﮐﺎر ﮔﺮﻓﺘﻪ ﺷﺪ. ﻓﺮآﯾﻨﺪ ﺳﻨﺘﺰ ﺑﺎ اﺳﺘﻔﺎده از ﻣﻘﺎدﯾﺮ ﻣﺨﺘﻠف MWNCT (2، 4، 6 و 8 درصد وزني) اﻧﺠﺎم ﺷﺪ. ﻣﯿﮑﺮوﺳﮑﻮپ اﻟﮑﺘﺮوﻧﯽ روﺑﺸﯽ (SEM)، ﺗﻔﺮق اﺷﻌﻪ اﯾﮑﺲ (XRD)، ﻃﯿﻒ ﺳﻨﺠﯽ ﻣﺎدون ﻗﺮﻣﺰ ﺗﺒﺪﯾﻞ ﻓﻮرﯾﻪ (FTIR)، آﻧﺎﻟﯿﺰ ﺣﺮارﺗﯽ ﻫﻤﺰﻣﺎن (STA)، رﻓﺘﺎر دي اﻟﮑﺘﺮﯾﮏ و ﺗﺎﺛﯿﺮ ﺣﻔﺎﻇﺖ ﺗﺪاﺧﻠﯽ اﻣﻮاج اﻟﮑﺘﺮوﻣﻐﻨﺎﻃﯿﺲ (Electro-Magnetic Interference Shielding Effectiveness) ﮐﻪ ﺑﺎ EMI SE ﺑﯿﺎن ﻣﯽ ﺷﻮد، ﺟﻬﺖ ﻣﺸﺨﺼﻪ ﯾﺎﺑﯽ ﻧﺎﻧﻮﮐﺎﻣﭙﻮزﯾﺘﻬﺎ ﻣﻮرد اﺳﺘﻔﺎده ﻗﺮار ﮔﺮﻓﺘﻨﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ EMI SE ﻧﺎﻧﻮﮐﺎﻣﭙﻮزﯾﺖ ﻫﺎي ﺳﻨﺘﺰ ﺷﺪه ﻧﺴﺒﺖ ﺑﻪ ﻧﻤﻮﻧﻪ ﻣﺸﺎﺑﻪ ﮐﻪ از روش ﻫﺎي دﯾﮕﺮ ﺗﻬﯿﻪ ﺷﺪه، ﺑﻬﺒﻮد ﯾﺎﻓﺘﻪ ﮐﻪ ﻧﺎﺷﯽ از اﺧﺘﻼط و ﺗﻮزﯾﻊ ﻫﻤﮕﻦ ﻧﺎﻧﻮﻟﻮﻟﻪ ﻫﺎ در ﺑﯿﻦ ذرات اﺳﺖ. ﻫﻤﭽﻨﯿﻦ ﻣﻘﺪار EMI SE ﮐﺎﻣﭙﻮزﯾﺖ ﺑﺎ ﺿﺨﺎﻣﺖ 1/5 ﻣﯿﻠﯿﻤﺘﺮ ﮐﻪ ﺷﺎﻣﻞ 8 درﺻﺪ وزﻧﯽ MWCN ﺑﻮده و در دﻣﺎيC 750° ﺳﯿﻨﺘﺮ ﺷﺪه ﺑﯿﺶ از dB 28 ﺑﺪﺳﺖ آﻣﺪ ﮐﻪ ﻧﺸﺎن دﻫﻨﺪه ﻗﺎﺑﻠﯿﺖ ﻣﺎده ﺑﺮاي ﺟﺬب اﻣﻮاج در ﻣﺤﺪوده ﻣﺎﯾﮑﺮووﯾﻮ اﺳﺖ. اﻧﺪازه داﻧﻪ ﻧﺎﻧﻮﮐﺎﻣﭙﻮزﯾﺖ ﻧﯿﺰ ﺣﺪود 97 ﻧﺎﻧﻮﻣﺘﺮ ﺑﺪﺳﺖ آﻣﺪ.

Abstract: The present research investigated the preparation of a multi-walled carbon nanotube (MWCNT)-barium titanate/silica nanocomposite using a sol-gel technique. The synthesis process was conducted using different amounts of MWCNT (2, 4, 6 and 8 wt%). Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Simultaneous thermal analysis (STA), Dielectric behavior and Electromagnetic interference shielding effectiveness (EMI SE) were used to characterize the as-synthesized specimens. It was found that the applied sol-gel process for synthesis of MWCNT-BaTiO3/silica nanocomposite provided the material with higher EMI SE value compared to the same nanocomposite prepared by the other methods. This can be attributed to a good mixing and homogeneous distribution of MWCNTs and other composite constituents. Results also indicated that incorporation of 8 wt% MWCNT into 1.5 mm-thick nanocomposite led to an EMI SE greater than 28 dB, suggesting this novel nanocomposite as a promising candidate for microwave absorption and electromagnetic interference applications. The grain size of 98 nm for the nanocomposite prepared with 8 wt% MWCNT was also concluded. This can be achieved through sintering process of the nanocomposite at appropriate temperature (750°C).