Self-Assembled Behavior of Ultralightweight Aerogel from a Mixture of CNC/CNF from Oil Palm Empty Fruit Bunches.

Dian Burhani,Athanasia Amanda Septevani,Dewi Sondari,Muhammad Andrew Putra,Ruby Setiawan,Sukma Surya Kusumah,Luthfia Miftahul Djannah

doi:10.3390/polym13162649

Dian Burhani, Athanasia Amanda Septevani + Show 5 more

Open Access

https://doi.org/10.3390/polym13162649

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Abstract

This study aims to explore the use of cellulose nanocrystals (CNC) and cellulose nanofiber (CNF), obtained from unbleached fiber of oil palm empty fruit bunches (EFB), as raw materials in fabricating aerogel, using the facile technique without solvent displacement. The CNC was isolated from sulfuric acid hydrolysis, and the CNF was fibrillated using Ultra Turrax. The CNC and CNF were mixed by ultrasonication in different ratios to produce aerogel using slow freezing (−20 °C), followed by freeze-drying. The obtained aerogel was characterized as ultralightweight and highly porous material, at the density range of 0.0227 to 0.0364 g/cm3 and porosity of 98.027 to 98.667%. Interestingly, the ratio of CNC and CNF significantly affected the characteristics of the obtained aerogel. The mixed aerogel exhibited a higher specific surface area than pure CNC or CNF, with the highest value of 202.72 m2/g for the ratio of 1:3 (CNC/CNF). In addition, the crystallinity degree of obtained aerogel showed a higher value in the range of 76.49 to 69.02%, with the highest value being obtained for higher CNC content. This study is expected to provide insight into nanocellulose-based aerogel, with a promising potential for various applications.

Highlights

Aerogel, a highly porous material with ultralightweight density, has been an industrial and scientific interest for the last decade for its unique properties, such as thermal conductivity, flame and moisture resistance, low optical index of refraction, and low dielectric constant [1]
Silica aerogel was first synthesized by Kistler using sol-gel chemistry, in which the removal of the solvent was conducted through supercritical drying
This study aims to utilize the cellulose nanocrystals (CNC) and cellulose nanofiber (CNF) obtained from the unbleached fiber of oil palm empty fruit bunches in fabricating aerogel, using the freeze-drying method without the addition of chemical solvents

Summary

Introduction

A highly porous material with ultralightweight density, has been an industrial and scientific interest for the last decade for its unique properties, such as thermal conductivity, flame and moisture resistance, low optical index of refraction, and low dielectric constant [1]. Aerogel mostly consists of air or gas, resulting in a lightweight and high porosity. It exhibits a mixture of mesopore and macropores structure and a high specific surface area [1]. Aerogel has been widely used in various applications, including oil absorbent [2], water treatment [3], fire-resistant [4], energy storage [5], absorption [6], thermal insulation [7], drug delivery [8], and membrane separation [9].

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