JOURNAL OF NATURAL FIBERS
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Table 4. Properties of paper loaded with carbon nanotubes. Type of sample
properties
references
(Salajkova
MWCNT various contents (0–16.7 wt%) in nanopaper
A slight decrease in modulus of elasticity with increasing concentrations of MWCNT (0–16.7 wt%). The highest one was for control nanopaper (9.26 GPa) compared to 2,6 GPa for 16.7 wt% MWCNT. The same behavior was observed for tensile strength and a significant decrease in strain failure at very low MWCNT loading (0.5 to 1 wt%), However, higher than 2 wt% the strain to failure increased back to its original value. AT 7.4 wt% MWCNT the strength is 210 MPa and the strain to failure is 7.2%. Young’s modulus The highest tensile strength (6.50 N/m) was recorded for 2.4 wt% CNT in composite paper and the lowest for 16.7 wt% CNT in paper with a value 4.36 N/m. The highest surface resistivity 9.12 Ω/ѕ also exhibited by 16.7 wt% CNT and the lowest for 0.5 wt% CNT with a value of 3.39 x 10 5 Ω/ѕ. The highest volume resistivity was observed for 1.0 wt% with a value of 7.25 Ωcm as compared to 1.49 x 10 −1 Ωcm for 16.7 wt% CNT. MWCNTs suspension coated paper imparted lower electro-conductivities (595S m −1 , respectively). The breaking length for MWCNT/NCC coated paper was 6.11 ± 0.22 km (machine direction, MD) and 2.38 ± 0.16 km (cross direction, CD). Whereas for tearing strength was 1224 ± 37 mN (MD) and 1462 ± 49 mN (CD).
et al. 2013)
CNT with various content (0.5 to 16.7 wt%)
(Imai et al. 2010)
MWCNT coated paper with nanocellulose
(Tang et al. 2014)
Characterization. The incorporation of CNTs into the paper matrix resulted in a minor reduction in the tensile index and bursting index. These indices serve as measures of the paper’s strength and ability to withstand external forces. The presence of CNTs appears to have weakened these properties to some extent, suggesting a potential trade-off between their added benefits and the structural integrity of the paper. As the CNTs integrate into the paper matrix, they establish connections with neighboring cellulose fibers, creating an interconnected network structure. While this network enhances certain aspects of the paper’s perfor- mance, it also disrupts the hydrogen bonding between cellulose fibers, which contributes to the overall strength of the paper (Imai et al. 2010). The tearing index demonstrated a slight increase, despite the decrease in tensile and bursting indices. The tearing index reflects the paper’s resistance to tearing, an important characteristic for certain applications. The rise in the tearing index suggests that the incorpora- tion of CNTs may have enhanced the paper’s tear strength, counterbalancing its compromised tensile and bursting properties. Table 4 shows the mechanical properties of paper loaded with carbon nanotubes. Application. Carbon nanotubes (CNTs) are extensively used in electronic devices due to their exceptional properties, including high heat and electrical conductivity. The composite materials (CNTs added in pulp) find applications in various portable devices, such as next-generation computers, consumer electronics, wireless LAN devices, wireless antenna systems, and cellular phone systems. CNTs enable efficient heat dissipation, preventing overheating issues and improving device performance. Additionally, their excellent electrical conductivity enhances signal transmission, resulting in faster data processing and reliable wireless communications. With the increasing demand for portable electronic devices, the utilization of CNT-based composite materials is expected to continue growing, driving advancements in the field of electronics.
UV protection and photostability Nano Zinc Oxide
Nano zinc oxide, or nano ZnO, is another mineral additive from a mineral that is used as a pigment for brightness and for paper coating (Sobri, Ainun, and Zainudin 2018). It also provides anti-fungal properties and UV protection (Ma et al. 2016; Sobri et al. 2021). Furthermore, nano ZnO shows better microbial activity without photoactivation to activate this property as compared with TiO 2 , which needs photoactiva- tion for use to activate the antimicrobial activity (Azizi-Lalabadi et al. 2019). It exists as a mineral called zincite and is considered environmentally friendly and nontoxic (Sobri et al. 2021). One study used this nano ZnO with hybrid components in starch composites as a stabilizing agent (Ma et al. 2016). The nano ZnO that comes from inorganic oxide compounds has advantages such as robustness, high stability when heated at elevated temperatures, the ability to withstand harsh conditions, and a long shelf life (Kołodziejczak-Radzimska and Jesionowski 2014; Stoimenov et al. 2002). In a study by Ma et al. (Ma et al. 2016) on nano ZnO that was mixed with starch in paper coating, it was shown that the ZnO-starch nanocomposite and ZnO nanoparticles successfully blocked UV radiation and had a superior antibacterial capability. Furthermore, compared to uncoated paper, the coated paper improved the smoothness and
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