Improvement of mechanical and barrier properties of biopolymer nano-composites for packaging applications

Project leaders

Daniela Caschera, Abeer Adel

Agreement

EGITTO - NRC - National Research Centre of Egypt

Call

CNR/NRC biennio 2018-2019 2018-2019

Department

Chemical sciences and materials technology

Thematic area

Chemical sciences and materials technology

Status of the project

New

Research proposal

Packaging is one of the most essential and dominant elements in branding for the different market products in several sectors such as food, cosmetics, toys, instruments, drugs and others. However due to the up-raising challenges for raw materials scarcity, a lot of efforts are exerted to find substituting materials which are more locally available, environmentally safer and cheaper with better, or at least, the same characteristics. Nowadays, eco-friendly food packaging attracts global attention, because, unlike petroleum derivatives, the most relevant advantages of bio-composite package are safety, biodegradability and low cost.
In this regard, the need for multifunctional food packaging with mechanical, barrier, transparency and antimicrobial properties can be achieved through the bio-composite systems formation, leading to the development of renewable and biodegradable biopolymers reinforced composite materials. One of the most potential sustainable and green materials in packaging fields is the agriculture residues due to its availability and characteristics. Agriculture residues are produced in Egypt annually in huge amounts; the usage of them in different applications is considered as an economic add value to the Egyptian economy. Moreover, one of the more promising materials to be used as reinforcing elements in biopolymer composites (paper, chitosan, alginate and soy protein films) is the cellulose nanocrystals (CNC), that can be extracted from several agriculture residues (bagasse, cotton stalk and date palm tree). Carboxylate groups in CNCs offers active sites for enhancing the adhesion of CNCs onto coating substrates in order to produce new high performing, more sustainable multilayer materials for critical packaging applications. Nevertheless, important properties for a barrier layer include good mechanical strength properties, a suitable degree of flexibility and specific properties such as antibacterical and/or photo-catalytical behavior. The use of metal and/or metal oxide nanoparticles (Au, Ag, Cu, TiO2, ZnO) with an appropriate binder in the coating formulation will help to fill the micro-voids and could offer the possibility to better conjugate the barrier properties with strong antibacterial activity at low concentrations for paper sheets. Due to the high surface area, the presence of reductive functional groups and their water suspend ability, CNCs can also act as both supporting and reducing agent for the generation of metal and metal oxide nanoparticles, avoiding the use of toxic reductants such as hydrazine and sodium borohydride. These as-synthesized nanosystems can be used to functionalize the biopolymers and then incorporated on the paper matrices. Moreover, due to the porous structure and hydrophilicity of fiber surface, paper matrices can absorb a suspension of nanoparticles via capillary forces leading to higher loading of metal nanoparticles. In this way the good properties of paper as packaging substrate (biodegradable, biocompatible, cost effect and renewable) could be conjugated with new functionalities. In this study, Ag and TiO2 nanoparticles will be synthesized, both via chemical synthesis and using directly CNCs as reducing/stabilizing agents. The Np-CNCs systems will be used to functionalized the biopolymer used in packaging applications. A complete structural, morphological and chemical-physical characterization of the extracted CNC, of the Ag-CNCs, TiO2-CNCs nanosystems before and after the biopolymer functionalization and their embedding on the paper, will be performed, to detect the crystal structure, the morphology, the optical properties and the surface area of the nanoparticles. Changes in wettability of the paper sheet after blending with the nanocomposites will be evaluated by water contact angles measurements (WCAs). Also, the effect of the nanomodification on the mechanical strength and barrier properties of paper sheets will be investigated. The antimicrobial and the photodegradation properties of the nanosystems will be also evaluated. The Egyptian team, thanks to their validated experience in treatment of cellulose, will be involved in the extraction of CNCs from agriculture residues (A.M. Adel, M. El-Sakhawy, M.T. Al-Shemy) and their characterization by zeta potential, XRD, TEM and FTIR ( A.M. Adel, N. El-Shinnawy, M.T. Al-Shemy). Then, in collaboration with Italian team, they will supervise to the preparation of the biopolymer/nanocomposite films, for safety food packaging, and provide to the studies of mechanical and barrier properties of as-nanomodified paper sheets(A.M. Adel, M.A. Diab, M. El-Sakhawy). The Italian team has a consolidated experience in the fabrication and characterization of metal nanoparticles and multifunctional oxide nanomaterials. They will be involved in the preparation of Ag (D. Gentili) and TiO2 nanoparticles (D. Caschera, R.G. Toro), in the structural and morphological characterization by UV-Vis, µRaman, XPS, SEM, AFM, DLS, ¶- potential measurements, WCAs and TEM (F. Valle, M. Brucale, D. Caschera, D. Gentili) and in the functionalization of CNCs (R.G. Toro and D. Gentili) for optimization of antibacterical and photocatalytical properties.
This collaboration, necessary for the specific skills of all the researchers involved, can become a starting point for settling a new collaboration between Italy and Egypt, with the opportunity to establish a wider network of people and institutions, in the packaging application field. This project can represent a good opportunity to both Egyptian and Italian packaging industries for developing innovative, eco-friendly, cheaper and functionally effective new food safety packaging materials. This project is also an opportunity to involve and encourage an efficient participation of young scientists, in particular a Italian young post-doc researcher (D. Gentili) and an Egyptian young assistant researcher (M. Tawfik Al-Shemy) will be involved actively in the project

Research goals

General objective: Developing new, innovative and safer products and technologies for the food packaging industry.
Specific objective:
(1) Extraction of cellulose nanocrystals (CNCs), from Egyptian local raw agriculture residues and use them as biopolymer reinforce
In this way, it could be possible to increase the economic value of the Egyptian agriculture residues through converting them into needed high value industrial products and at the same time a decrease of environmental hazardous due to the unsafe disposal of the agriculture residues by burning. Moreover, the CNCs use for improving the mechanical and barrier properties of paper sheets in packaging field could take to a decrease of the cost in food packaging industries operation.
(2) Developing Nanoparticles modified-CNC/ biopolymer composites.
Ag and TiO2 nano-functionalization of CNCs could impart new and innovative properties to packaging paper, such as specific antimicrobial and photocatalytic behavior. This could permit to formulate innovative solutions and new food safety packaging compounds, of potential interest for transferring to the Italian and Egyptian packaging industries.

Last update: 20/04/2024