production and characterization of poly (lactic acid) based nano-bio-composites properties containing natural nano-clays and nano-silvers

In this research, to improve the properties of poly lactic acid (pla), nanocomposite films have been prepared by the addition of (1.00-3.00) wt% nanoclay (cloisite 30b) and (0.2-1.00) wt% silver (ag) nanoparticles in the pla matrix using solvent casting method. additionally, nanocomposite materials have been investigated in terms of mechanical, humidity, optic, and coloral and antibacterial responses. furthermore, their optimum values have been determined by central composite design of response surface methodology (rsm). the elasticity module (e) and tensile strength (ts) values showed that quadratic effect of nanoclay and nanosilver concentrations were significant. moreover, optimum level of nanoclay and nanosilver for obtaining maximum e and ts were 2.03, 0.55 wt% and 1.97, 0.55 wt%, respectively. the water uptake data showed that linear, 2 fi and quadratic effect of nanoclay and nanosilver concentrations were significant. optimum level of nanoclay and nanosilver for obtaining maximum were 2.77 and 0.85 wt%, respectively. linear effect of nanoclay concentrations on water vapor permeation and uv transmittance, also linear effect of nanoclay and nanosilver concentrations on contact angle were significant. thus, in these investigated parameters optimum level of nanoclay and nanosilver for obtaining desired result were 3.0 and 1.0 wt% respectively. as a result, nanocomposite films showed desired transparency properties. furthermore, their antibacterial activities against staphylococcus aureus and escherichia coli cells were detected. consequently, these nanocomposite films may offer good idea for food packaging applications.