facile surface modification of polyethylene film via spray-assisted layer-by-layer self-assembly of graphene oxide for oxygen barrier properties - barrier films for food packaging
Oxygen barrier properties are essential for food packaging systems that preserve perishable foods.
In this study, the use of spray-assisted layers-by-layer (LbL)self-assembly. The nano-
Graphene oxide size (GO−)
Multi-layer films were developed and characterized.
Amine with positive electricity
Use GO dispersion with negative charge, ethylene glycol and 1-(3-
Iodine acetate ketone (EDC).
The alternating layers of GO and GO are deposited on flexible polyethylene (PE)
Substrate without inherent gas barrier properties.
This method is able to modify surfaces that are challenging for the traditional immersion LbL method.
Oxygen penetration rate of coated PE film (3511. 5 cc/m2·day)
After the deposition of the GO film with a thickness of only 60 nm, it was significantly reduced to 1091 cc/m2 day.
After coating the GO film, the light transmission ratio within the visible light range is not significantly reduced, thus ensuring the transparency of PE packaging applications.
Gas barrier properties are essential for protecting films of perishable items such as food or electronics.
In particular, oxygen barrier properties play a vital role in food packaging applications, as the greatest loss of quality in food is due to oxygen in permeable gases. Polyethylene (PE)
Due to its transparency, flexibility and low cost in food packaging, it has become one of the most widely used polymer materials.
However, the poor gas barrier performance of polymer film limits its application in commercial food packaging.
Therefore, many researchers have made great efforts to enhance the barrier properties of polymer films by applying barrier films to the barrier materials that will form nano-composites or by coating barrier films on PE surfaces.
Nano-composites consisting of inorganic materials or organic clay show enhanced oxygen barrier properties, but maintaining their optical clarity remains challenging due to poor dispersion of inorganic or organic clay particles.
Graphene and graphene oxide (GO)are well-
Known, the atom is thin, two-
Size blocking material with excellent gas blocking and mechanical properties.
The high aspect ratio and plane 2D structure of GO nano-platelets are called non-penetration to most gases. Kuila .
The team added the GO sheet of the oxygen barrier film to the polymer matrix.
Further functional processes are required for the dispersion of GO sheets in polymer substrates.
Depending on the internal structure of the composite film, the gas permeability through the film can be increased or decreased.
The random orientation of platelets or the level in the mixed matrix membrane (MMMs)
Gas penetration is suppressed through tortuous diffusion pathways, while the vertical direction of platelets provides faster penetration because they provide a fast transport channel.
Non-surface coating method
Permeable materials are widely used in the performance of oxygen barrier.
A multi-layer film composed of GO alternating deposition and polyelectrolyte such as polyethylene amine (PEI)
, Vinyl alcohol (PVA)
, Or polypropylene hydrochloride (PAH)via layer-by-layer (LbL)self-
Assembly has been reported. LbL self-
Assembly is good-
Nano-film manufacturing methods have been developed to accurately control the thickness and internal composition of the film through various complementary interactions, and can be used with various materials.
Multi-layer structure of GO can be prepared by LbL self-reaction
Assembly and oxygen must penetrate the GO coating through the tortuous path of the densely stacked GO layer, resulting in the reduction of OTR. LbL self-
Chen, additional materials are required to assemble GO sheets that can interact with GO sheets.
Made dozens of nanometers.
Thick GO/polyelectrolyte LbL membrane on 125 μm-
The thick PET substrate of 99 was obtained.
OTR fell 6%. Jaime C.
The research group reported graphene oxide/polymer multilayer films and obtained high oxygen hydrogen barrier properties.
In order to achieve high performance, supplementary materials with negative power GO should be carefully selected.
In our work, we have designed an amino-functional GO for GO.
Both GO and GO have excellent gas barrier properties, not only the electrostatic interaction between the amino group of GO and the amino group of GO, but also the pi-
Pi interactions ensure a tight bond between each layer.
Many previous studies on the properties of oxygen barrier are based on thick polyphenyl (PET)
Films that already have intrinsic oxygen barrier properties, there are few reports of modification of flexible PE films with little intrinsic oxygen barrier properties.
The PE film we use as a substrate is a widely used packaging material with high flexibility and low oxygen barrier properties in itself.
In addition, the traditional immersion LbL from
Due to the shear stress during the immersion process, it is difficult to assemble a stable membrane on a flexible PE membrane, and the oxygen barrier performance has not been improved due to cracks.
So we introduced a simple spray.
Auxiliary LbL deposition method.
Although the improvement of the oxygen barrier is not high compared with previous studies, we have successfully reduced the OTR of the flexible PE film by spraying the auxiliary LbL self-coating GO/GO multi-layer filmassembly.
Here we introduce the simple spray
Assemble GO on thin flexible PE substrate without complementary polyelectrolyte. The spray-
Auxiliary program to make height
Dense and orderly deposition
Packed multi-layer GO film to large-
The flexible PE substrate can be provided while maintaining high transparency.