Cellulose Nanocrystals (CNCs) from Corn Stalk: Activation Energy Analysis

Abstract

Cellulose nanocrystals (CNCs) were isolated from corn stalk using sulfuric acid hydrolysis, and their morphology, chemical structure, and thermal stability properties were characterized. The CNCs had an average length of 120.2 ± 61.3 nm and diameter of 6.4 ± 3.1 nm (L/D = 18.7). The degree of crystallinity of the CNCs increased to 69.20% from the 33.20% crystallinity of raw corn stalk fiber, while the chemical structure was well kept after sulfuric acid hydrolysis. Thermal stability analysis showed that the degradation temperature of the CNCs reached 239.5 °C, which was higher than that of the raw fiber but lower than that of the extracted cellulose. The average activation energy values for the CNCs, evaluated using the Friedman, Flynn-Wall-Ozawa (F-W-O) and Coats-Redfern methods, were 312.6, 302.8, and 309 kJ·mol−1 in the conversion range of 0.1 to 0.8. The isolated CNCs had higher values of activation energy than did the purified cellulose, which was attributed to the stronger hydrogen bonds present in the crystalline domains of CNCs than in those of cellulose. These findings can help better understand the thermal properties of polymer/CNC composites.

Ekstraksi Dan Karakterisasi Mikroselulosa Dari Rumput Laut Coklat Sargassum Sp. Sebagai Bahan Penguat Bioplastik Film

“…Proses ekstraksi mikroselulosa dalam penelitian ini mengacu kepada metode Huang et al (2017) dan Wulandari et al (2016) dengan sedikit modifikasi. Proses ini dilakukan dua tahap yaitu pertama adalah proses alkalinisasi dan tahap kedua adalah proses hidrolisis.…”

“…Kumar et al, 2014 telah berhasil mendapatkan nanoselulosa dalam ampas tebu dengan proses hidrolisis menggunakan larutan 64 % w/w H2SO4 (Kumar et al 2014). Begitu juga Huang et al, 2017 juga sukses menghasilkan nanoselulosa dari batang jagung yang dihidrolisis di dalam 60 wt % H2SO4 (Huang et al 2017). Pengaruh waktu proses dan kecepatan pengadukan diharapkan menghasilkan gaya geser karena tumbukan.…”

“…Hal ini kemungkinan karena proses alkanisasi yang dilakukan sudah dapat menguraikan hemiselulosa dan lignin yang melekat pada permukaan selulosa. Huang et al, 2017 juga melaporkan bahwa foto SEM selulosa proses alkanisasi terlihat seperti butiran-butiran kecil yang diselubungi bagian halus yang menandakan adanya pengangkatan hemiselulosa dan lignin (Huang et al 2017). Namun pada Gambar 6c yaitu mikroselulosa terlihat terlihat bayangan garis-garis panjang.…”

Cellulose Nanocrystals as a Sustainable Raw Material: Cytotoxicity and Applications on Healthcare Technology

“…Concerning the renewable sources of raw materials, there are several possible lignocellulosic materials for the isolation of whiskers: vegetable sources, such as cotton, coconut fiber, corn cobs, pineapple leaves, manioc residues, palm fiber, residual biomass from palm oil extraction, banana fibers, hemp, wood pulp, old newspaper and recycled newsprint, microcrystalline cellulose (MCC), bacterial cellulose, the product of which is named bacterial nanocellulose, microbial cellulose or biocellulose, and animal sources, such as tunicates and marine biomass …”

Effect of Corncob Cellulose Nanoparticles on Silicate-Based Mud at High Temperature

“…The thermal stability of CNPs is influenced by their physical and chemical structure. 25 The higher crystallinity of the cellulose obtained after the removal of hemicellulose and lignin components is related to the higher thermal stability of fibers.…”