Layer-by-layer deposition of green synthesised silver nanoparticles on polyester air filters and its antimicrobial activity

Figures & data

Figure 1. Absorbance spectra of green synthesised silver nanoparticles stabilised with (a) PMA, (b) PAA, (c) CoPSS and (d) chemical reduction of silver nanoparticles stabilised with PMA, PAA and CoPSS.

Table 1. Zeta potential of silver nanoparticles.

Technique	Stabilising agent	Zeta potential, mV
Green synthesis	PMA	–37.90
	PAA	–33.12
	CoPSS	–27.36
Chemical reduction	PMA	–34.22
	PAA	–29.15
	CoPSS	–25.13

Figure 2. TEM images of (a) green synthesised silver nanoparticles and (b) chemical reduction of silver nanoparticles.

Figure 3. FESEM images and EDS of (a) green synthesised silver nanoparticles and (b) chemical reduction of silver nanoparticles onto polyester air filters.

Table 2. Contact angle of 10 layers of silver nanoparticles coated on polyester air filters.

Technique	Stabilising agent	Contact angle (degree)
	PMA	84
Green synthesis	PAA	79
	CoPSS	70
	PMA	77
Chemical reduction	PAA	72
	CoPSS	69

Table 3. Antimicrobial activity of polyester air filters coated with silver nanoparticles.

		Reduction of S.aureus. (% )
Technique	Stabilizing agent	10 layers	5 layers
Green synthesis	PMA	92.18	83.94
	PAA	84.32	76.12
	CoPSS	71.19	66.59
Chemical reduction	PMA	85.32	74.98
	PAA	80.22	71.13
	CoPSS	69.37	61.09
Blank of air filters		1.73
Air filters coated with five layers PDADMAC/PSS		2.18