Nanofibrillated cellulose/nanographite composite films

Abstract

Though research into nanofibrillated cellulose (NFC) has recently increased, few studies have considered co-utilising NFC and nanographite (NG) in composite films, and, it has, however been a challenge to use high-yield pulp fibres (mechanical pulps) to produce this nanofibrillar material. It is worth noting that there is a significant difference between chemical pulp fibres and high-yield pulp fibres, as the former is composed mainly of cellulose and has a yield of approximately 50 % while the latter is consist of cellulose, hemicellulose and lignin, and has a yield of approximately 90 %. NFC was produced by combining TEMPO (2,2,6,6-tetramethypiperidine-1-oxyl)-mediated oxidation with the mechanical shearing of chemi-thermomechanical pulp (CTMP) and sulphite pulp (SP); the NG was produced by mechanically exfoliating graphite. The different NaClO dosages in the TEMPO system differently oxidised the fibres, altering their fibrillation efficiency. NFC-NG films were produced by casting in a Petri dish. We examine the effect of NG on the sheet-resistance and mechanical properties of NFC films. Addition of 10 wt% NG to 90 wt% NFC of sample CC2 (5 mmol NaClO CTMP-NFC homogenised for 60 min) improved the sheet resistance, i.e. from that of an insulating pure NFC film to 180 X/sq. Further addition of 20 (CC3) and 25 wt% (CC4) of NG to 80 and 75 wt% respectively, lowered the sheet resistance to 17 and 9 X/sq, respectively. For the mechanical properties, we found that adding 10 wt% NG to 90 wt% NFC of sample HH2 (5 mmol NaClO SP-NFC homogenised for 60 min) improved the tensile index by 28 %, tensile stiffness index by 20 %, and peak load by 28 %. The film's surface morphology was visualised using scanning electron microscopy, revealing the fibrillated structure of NFC and NG. This methodology yields NFC-NG films that are mechanically stable, bendable, and flexible.

Thin Electric Heating Membrane Constructed with a Three-Dimensional Nanofibrillated Cellulose–Graphene–Graphene Oxide System

“…The electrical properties can be controlled by changing the parameters of thickness, weight per unit area, or the composition. Much lower sheet resistivities of 1.75 to 9 Ω/sq have been demonstrated previously for membranes with the adjusted parameters [ 17 , 20 , 33 ]. Furtherly, the conductivity of membranes with various grammages (50 wt.% graphene) were investigated in this presented study.…”

“…This phenomenon means that the membrane can be suitably made thinner and lighter, which is beneficial for the preparation of large surfaces. Generally, research into graphene-based membranes has been carried out with higher grammages, ranging from 25 to 250 g·m −2 [ 17 , 33 ], because thicker membranes show better conductivity. In which, the electrical parameters are shown in Table S2 (Supplementary Materials) , and a fluctuant process in the first test is shown in Figure S8 (Supplementary Materials) .…”

Well‐dispersed polyurethane/cellulose nanocrystal nanocomposites synthesized by a solvent‐free procedure in bulk

“…In the early 1990s, seminal works on chiral nematic ordering of CNCs [2] and mechanical reinforcements for polymer [3] were reported. Since then, CNCs have attracted attention of a large section of the materials community [4][5][6][7][8][9][10][11][12][13][14][15][16][17]. The main benefits attributed to CNCs are their high strength, wide availability, low cost (relative to the other NPs), renewable origin, low density and high aspect ratio.…”

Extraction of nanofibers from polymer blends: A brief review

“…The subject is wide and extensively reviewed and thus cannot be placed in the present short review. Osong et al reviewed the processing of wood‐based microfibrillated and nanofibrillated cellulose . It is believed that the annual number of research publications and patents on nanocellulose is now up in the thousands and it has attracted considerable interest among researchers .…”

“…Osong et al reviewed the processing of wood‐based microfibrillated and nanofibrillated cellulose . It is believed that the annual number of research publications and patents on nanocellulose is now up in the thousands and it has attracted considerable interest among researchers . Nechyporchuk et al in a comprehensive review paper discussed different issues and the advances in production of cellulose nanofibrils that are otherwise known as nanofibrillated cellulose, microfibrillated cellulose, or cellulose nanofibers .…”