Synthesis and Characterization of Silica and Carbon Aerogels from Hemp Fiber via freeze-drying Process

Year 2020, Volume: 20 Issue: 6, 1079 - 1084, 31.12.2020

Alime Çıtak

https://doi.org/10.35414/akufemubid.789007

Abstract

In this study, it was aimed to synthesize and characterize cellulose based silica carbon aerogel by sol-gel method. Pooled and hand-peeled hemp fibers were used as the source of cellulose at the time of October-2018 harvest in Vezir Köprü, Samsun province. Hemp fiber containing crude cellulose was mechanically made into cellulose pulp. Then, Silica aerogel (SA) sample was synthesized by Sol-gel method and subsequent freeze-drying process. Finally, the synthesized SA sample was kept in a tube oven at a heating rate of 5 oC/min under a nitrogen flow of 120 ml/min for 2 hours at 500 oC to obtain cellulose-based carbon aerogel (SCA). Synthesized samples; Scanning Electron Microscopy (SEM), Energy dispersive spectrometer (EDS), Surface analysis measurement (BET), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction method (XRD) and electrical conductivity analyzes were performed. As a result of electrical conductivity analysis, the electrical resistances of the silica aerojels was found to be very high. It was interpreted that the synthesized samples could be used as an insulator.

Keywords

Aerogel, Carbon aerogel, Freeze-drying, Hemp fiber, Sol-gel method

Freeze-drying İşlemi ile Kenevir Lifinden Silika ve Karbon Aerojellerin Sentezi ve Karakterizasyonu

Abstract

Bu çalışmada selüloz esaslı silika karbon aerojelin sol-jel yöntemi ile sentezlenmesi ve karakterize edilmesi amaçlanmıştır. Samsun ili Vezir Köprü'de Ekim-2018 hasadı sırasında toplanmış ve elle soyulmuş kenevir lifleri selüloz kaynağı olarak kullanılmıştır. Ham selüloz içeren kenevir lifi, mekanik olarak selüloz hamuru haline getirildi. Daha sonra Silika aerojel (SA) numunesi Sol-gel yöntemi ve ardından dondurularak kurutma işlemi ile sentezlendi. Son olarak, sentezlenen SA numunesi, selüloz esaslı karbon aerojel (SCA) elde etmek için 500 ° C'de 2 saat boyunca 120 ml / dakika azot akışı altında 5 oC / dakika ısıtma hızında bir tüp fırınında tutuldu. Sentezlenmiş örnekler; Taramalı Elektron Mikroskopisi (SEM), Enerji dağılım spektrometresi (EDS), Yüzey analizi ölçümü (BET), Fourier dönüşümü kızılötesi spektroskopisi (F-TIR), X ışını kırınım yöntemi (XRD) ve elektriksel iletkenlik analizleri yapıldı. Elektriksel iletkenlik analizi sonucunda silika aerojellerin elektrik dirençleri çok yüksek bulunmuştur. Sentezlenen numunelerin bir izolatör olarak kullanılabileceği yorumlandı.

Keywords

Aerojel, Karbon aerojel, Dondurarak kurutma, Kenevir lifi, Sol-gel yöntemi

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