Cellulose nanofiber thin-films as transparent and durable flexible substrates for electronic devices

Alteration of the Optical and Mechanical Characteristics of Cellulose Nanofibre Films Under Thermal Treatment

“…Colour changes in the thermally modified TO-CNF films Previously, thin CNF films produced using only mechanical treatment had ΔE* values of 6.1, 6.6, 7.3 and 10.5 at 80ºC, 120ºC, 160ºC and 190ºC (calculated from the figure), respectively (Pakharenko et al 2021). Therefore, the TO-CNFs in the current work (charge density: 1.0 mmol/g) were significantly more prone to thermal discolouration.…”

“…In the last years, several new biorefinery concepts have been established to produce cellulose nanomaterials at a larger scale, and the nanocellulose market is expected to grow from US$297 million in 2020 to US$783 million in 2025 (Nanocellulose market, 2020). This trend is promoted by the emerging green circular economy based on renewable resources, and by the unique features of nanocellulose, such as its superior mechanical properties, light weight, high surface area, optical transparency, low coefficient of thermal expansion and tailorable chemistry (Pakharenko et al 2021, Gan et al 2021).…”

“…The optical properties of nanocellulose are important parameters for films and nanopapers, and they may also be affected by elevated temperatures (thermal stress) (Pakharenko et al 2021). The optical properties of nanocellulose films have been commonly investigated by analysing the reflection, absorption, scattering or polarisation of light to obtain different variables, such as transmittance (Sun et al 2018), complex refractive index (Niskanen et al 2019b), optical activity (Zlenko et al 2019), colour (Vardanyan et al 2015), birefringence (Orellana et al 2018), opacity (Zhu et al 2011), and gloss (Kong et al 2019).…”

“…The optical properties of nanocellulose films have been commonly investigated by analysing the reflection, absorption, scattering or polarisation of light to obtain different variables, such as transmittance (Sun et al 2018), complex refractive index (Niskanen et al 2019b), optical activity (Zlenko et al 2019), colour (Vardanyan et al 2015), birefringence (Orellana et al 2018), opacity (Zhu et al 2011), and gloss (Kong et al 2019). The knowledge of the transformation of the optical characteristics of nanocellulose materials as a function of temperature is still incomplete, and the previous studies have mainly addressed the colour of cellulose nanomaterials (Pakharenko et al 2021). It has been found that the values of the colour differences and transmittance increase, and the value of lightness decreases, as a function of the heat treatment temperature.…”

Artemisia annua Stems a New Sustainable Source for Cellulosic Materials: Production and Characterization of Cellulose Microfibers and Nanocrystals

“…Hence, the exploitation of Artemisia annua plants to extract bioactive molecules will generate stem waste rich in lignocellulosic fibers, which can be used as an essential bio-based source for the extraction of cellulosic materials and their derivatives. Additionally, the global cellulose production from all resources is expected to rise significantly, from $250 million in 2019 to $783 million in 2025 [ 1 , 30 ]. Hence, the current work adds value to Artemisia annua stem residues as a source of cellulosic materials.…”