Preparation and Characterization of Soy Protein Isolate-Based Nanocomposite Films with Cellulose Nanofibers and Nano-Silica via Silane Grafting

Abstract

Soy protein isolate (SPI) has attracted considerable attention in the field of packaging technology due to its easy processability, biodegradability, and good film-forming characteristics. However, SPI-based films often suffer from inferior mechanical properties and high moisture sensitivity, thus restricting their practical application. In the present study, herein, a biobased nanocomposite film was developed by cross-linking SPI matrix from the synergistic reinforcement of cellulose nanofibers (CNF) and nano-silica (NS) particles. First, we functionalized the CNF with NS using a silane agent (KH560) as an efficient platform to enhance the interfacial interaction between SPI and CNF/NS, resulting from the epoxy-dominated cross-linking reaction. The chemical structure, thermal stability, and morphology of the resultant nanocomposite films were comprehensively investigated via Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). These results supported successful surface modification and indicated that the surface-tailored CNF/NS nanohybrid possesses excellent adhesion with SPI matrix through covalent and hydrogen-bonding interactions. The integration of CNF/NS into SPI resulted in nanocomposite films with an improved tensile strength (6.65 MPa), representing a 90.54% increase compared with the pristine SPI film. Moreover, the resulting composites had a significantly decreased water vapor permeation and a higher water contact angle (91.75°) than that of the unmodified film. The proposed strategy of synergistic reinforcements in the biobased composites may be a promising and green approach to address the critical limitations of plant protein-based materials in practical applications.

Enhanced electrical and dielectric properties of plasticized soy protein bioplastics through incorporation of nanosized carbon black

“…Generally speaking, the inherent high surface energy and assembly tendency of nanoparticles would result in nonuniform dispersion and weak filler‐matrix interface, which impair the enhancement of physical properties. However, certain surface modifications could improve the interactions between the filler and matrix, 27 which in turn lead to the uniform dispersibility and the better mechanical performance.…”

Full Bio‐Based Soy Protein Isolate Film Enhanced by Chicken Feather Keratin

“…Table 3 shows a comparison of TS and EB values of SPI film enhanced by different biomaterials. The adding of biomaterials to SPI, such as fiber [ 43,44 ] and chitin, [ 45 ] could effectively enhance SPI‐based film, resulting from the rigid nature of the fibers and the chitin molecules. However, due to the aggregation characteristics of fibers and the phase separation of additives with the SPI matrix, the reinforcement effect was limited, and the EB was reduced.…”

High-performance soy protein-based films from cellulose nanofibers and graphene oxide constructed synergistically via hydrogen and chemical bonding

“…In addition, the TSM of the original SPI lm was 46.14%, consistent with previous reports. 39 The dissolved matter of SG, SC, SE, SGC and SGCE composite lms decreased by 19.87%, 13.50%, 50.80%, 27.20% and 38.01%, respectively, relative to that of the pure protein lm. It is shown that the water-resistance of SPI-based composite lms was signicantly improved aer adding nanoparticles or the cross-linking agent.…”