This section will be focusing on the metal(Au, Ag, Pd, Ni) and also mineral (montmorillonite) where the nanomaterialshave been fused with the Nano-cellulose substrates 44. The nanocompositeshows great results in electrical, optical and catalytic properties. Nano-cellulose have different name which ismicro fibrillated cellulose (MFC) or Nano fibrillated cellulose (NFC),nanocrystalline cellulose (NCC) or cellulose nanocrystal (CNC); and bacterialcellulose (BC) 45. The characteristics of the Nano-cellulose are highspecific surface area, mechanical strength and high porous structure. It is theperfect platform to house the guest nanomaterial. Combining both Nano-cellulose-basednanocomposites and guest nanomaterial will usually power up the properties.
Thefusion between the guest nanomaterial and Nano-cellulose substrate can be donein three different ways:· formationof the guest nanomaterial in a Nano-cellulose dispersion· formation of the guest nanomaterial in thebulk structure of Nano-cellulose-based materials such as BC membranes· directcoating of the guest nanomaterial onto the Nano-cellulose surface as anano-sized layer The application of Nano-cellulose-based Nanocompositescan be done in several ways:1. Antimicrobial filters2. Catalysis3.
Pollutant sensors 3.1 Antimicrobial filters Antimicrobial materials can prevent thebiofilm growth and increase the filter life. A research was conducted where Chitosan-basedantimicrobial materials was used in the purification of drinking water 46. High number of AgNPs can be sustained in ahomogenous state due to the higher surface to volume ratio characteristic ofthe Nano-cellulose.
Thus, it can provide superior antimicrobial properties 47. Further study has been done where the Nano-cellulosesurface has been modified which it can reduces the risk of AgNP leakage byenhancing the capacity to restraining it 48. 3.2 Catalysis Nano-cellulose-based nanocomposites can act as thecatalytic decomposition of organic pollutants in the water.Guest nanoparticle (NP) that are used for catalyticapplication are mainly· photocatalystslike TiO2 · preciousmetals (Au, Ag, Pt) Nano-cellulose usually will act as a catalyst supportto slow down the nanoparticle accumulation. A research was conducted where a Nano-celluloseaerogel was coated with a 7 nm wide TiO2 layer using the chemicalvapour deposition technique. It was proved that under the observation of UVillumination, methylene blue on the nanocomposite was decomposed which showsits potential in water treatment application.
49. Other than this,research found out that TiO2 and Nano-cellulose nanocomposite showedfascination results of photoswitchable water super absorption. Precious metals (Au, AG, PT and Pd) are typicalmaterial used for catalysts. With the presence of Nano-cellulose, reducing metalsalts will be able to create Metal-NP and Nano-cellulose nanocomposites. Some of the reduction agents used is H2, NaBH4and Na3Citrate. 3.
3 Pollutant sensors The applications not only cover the antimicrobialfilters and catalyst but can also be employed as biosensors. The study has beendone by many researchers with the AuNP and Nano-cellulose nanocomposites 50, 51. There are some research done about the conductivity ofAuNP and BC by incorporate the nanocomposite in the electrode to identifychemicals electrochemically 52. Zhang et al.created the AuNP and BC nanocomposites and used them as sensors for H2O2and glucose detection 50. AuNP can also be function as different goal.
Researcher has found a method to vary the thickness of the SiO2 shellon the AuNPs from 15 to 100 nm which is done by generating a specificseparation between AuNPs and the homogenous coating of SiO2. On theAuNPs was produced. Thus, the thickness can be perceived by using thetransmission electron microscopy (TEM) images 53.