Mussel-Inspired Approach to Constructing Dual Network Coated Layered Clay for Enhanced Barrier and Antibacterial Properties of Poly(vinyl alcohol) Nanocomposites

Abstract

Inspired by complexation and mussel adhesion of catechol groups in tannic acid (TA), organophilic layered double hydroxides (LDHs@TA-Ti) were synthesized by forming a one-pot assembled TA-titanium (Ti) dual network coating on the surface of layered clay for the first time. LDHs@TA-Ti/poly(vinyl alcohol) (PVA) nanocomposites were prepared by the solution casting method. The results show that TA-Ti(IV) and TiO2 coordination compounds are simultaneously formed due to hydrolysis of titanium tetrachloride and complexation of TA in aqueous solution. Upon TA-Ti coatings onto the surface of LDHs, the antibacterial rate of LDHs@TA-Ti is up to 99.98%. Corresponding LDHs@TA-Ti/PVA nanocomposites also show outstanding antibacterial properties. Compared with pure PVA, LDHs@TA-Ti/PVA nanocomposites show a 40.9% increase in tensile strength, a 17.5% increase in elongation at break, a 35.9% decrease in oxygen permeability and a 26.0% decrease in water vapor permeability when adding 1 wt % LDHs@TA-Ti. UV transmittance (at 300 nm) of LDHs@TA-Ti/PVA nanocomposites decrease by 99.4% when the content of LDHs@TA-Ti reaches 3 wt %. These results indicate that PVA matrix incorporated with LDHs@TA-Ti could be used as a potential active packaging material to extend the shelf life of food products.

Nanocomposite Coatings Based on Polyvinyl Alcohol and Montmorillonite for High-Barrier Food Packaging

“…The molecular weight of AQ 4104 is 27.000 and the degree of hydrolysis is 98 to 99 mol% ( 36 ). The glass transition temperature, T g , is 74.8°C, the crystallization temperature is 193.3°C, and the melting temperature is 220°C ( 37 ).…”

Development of catechol‐functionalized chitosan/poly(vinyl alcohol) nanocomposite films incorporated with dual network coated layered clay for active packaging applications

“…The heating and cooling procedures referred to our published paper. 14 The crystallinity (χ) of PVA is calculated by the following formula, χ = [ΔH m /(ΔH 0 Â φ)] Â 100%, where ΔH m was the experimental melting enthalpy of the samples, ΔH 0 was the melting enthalpy of 100% crystalline PVA (163 J/ g), 19 and φ was the mass fraction of PVA in LDHs@TA-Ti/C-CS/PVA nanocomposite films.…”

“…Therefore, LDHs@TA-Ti/C-CS/PVA nanocomposite films show excellent antibacterial activity, which is the result of the synergistic effect from C-CS and TA-Ti coatings. 8,14,34…”

“…In our previous work, inspired by the mussel bionics, we have first reported a facile and green method to prepare catechol modified layered clay (layered double hydroxides, LDHs) coated by tannic acid (TA)-titanium (Ti) dual network complexes (LDHs@TA-Ti). 14 In the process of modification, the hydrolysis reaction of titanium tetrachloride (TiCl 4 ) and chelation reaction of catechol groups in TA occurred spontaneously in aqueous solution. Therefore, TA-Ti(IV) and TiO 2 complexes could be introduced into the network coating as crosslinking agents at the same time, which was different from the traditional TA-metal ion coordination system.…”

“…Therefore, TA-Ti(IV) and TiO 2 complexes could be introduced into the network coating as crosslinking agents at the same time, which was different from the traditional TA-metal ion coordination system. 14 The organic modification of layered clay based on bionics principle can not only improve the interfacial compatibility and dispersion of layered clay in the composite system, so as to improve its mechanical properties and water resistance, but also enhance its antibacterial and other active packaging functions, so as to expand the application of layered clay/polymer nanocomposites in the field of active packaging.…”