There were two main solution groups (also known as in-situ and ex-situ methods) applied to incorporate BC/KBC with various polymers Their aiming was still to improve BC/KBC properties, notably biocompatible, adsorption capacity, surface wettability, mechanical strength, shape, structure, crystallinity, and thermal stability that can be suitable for specific desired applications [73].
In the in-situ methods, the reinforcement polymers were added to the fermented media in BC/KBC production leading to directly attaching them to the 3-D fibril structure of created bio-films. BC/alginate nanocomposite was produced through the addition of 2% (w/v) alginate to the static culture medium of Komagataeibacter sucrofermentans for 5 days. This biocomposite was then recorded as possessing high antibiotic activity and suitable to be used as a wound dressing especially, against Staphylococcus aureus (Liyaskina et al. 2018). Nano bioactive glass was also used in the same way to prepare BC bioactive nanocomposites that possibly apply in biomedical industries Abdelraof et al.
(2019b). However, the current difficulties of these methods can be easily seen as several reinforcement polymers directly toxic BC/KBC _ synthesis microorganisms or decreased the rate of composite synthesis, leading to very low effection and yield. In addition, the non-uniform properties at all directionally of products, even decreasing or disturbing of pristine properties and structure of BC/KBC are also the big disadvantage of these modification efforts.
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For ex-situ method groups, harvested BC/KBC was impregnated, cast, blended, grafted/crosslinked, and cured with the polymer matrixes with the advantages such as non-causing antimicrobial related problems, maintaining BC/KBC pristine structure, and abundance in usable remforcement polymers namely collagen, chitosan, starch, hydroxyapatite, polyvinyl alcohol, polyurethane elastomer, polylactic acid, polymethyl methacrylate, polycaprolactone [73]. Nevertheless, difficult homogeneity control of products and incompatibility between BC/KBC and polymer matrixes have been again confirmed as the important drawbacks that arose and existed in the proceduces of these solutions. Table 5 presented a list of recent application research based on the combination of BC/KBC and various polymers and their improved properties.
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Table 5 List of recent research about the application of the combination of BC/KBC and various polymers and their improved properties (author’s elaboration).
BC/KBC Preparation Enhanced Desired Ref
based method properties application
materials
BC/gelatin In situ one- Tensile strength, Potential use in [177]
hydrolysate pot synthesis elongation at food
break, and thermal applications stability
BC/collagen _—In situ Antibacterial and Antioxidant [178]
plant phenolic method antioxidant biomaterials
compounds activity
KBC/chitosan Impregnation Water vapor Active food [131]
method permeability, packaging
antioxidant activity, and
against ultra violet
BC/polyvinyl Blending Adsorption Dyeing [179]
alcohol capacities wastewater
treatment
BC/polylactic Coating Barrier properties | Biomaterials [137]
acid method
BC/ Impregnation Biocompatibility | Wound [180]
polyethylene method and antibacterial dressings glycol/poly-
hexamethylene biguanidine
KBC/poly- Blending Eco-friendly Nonwoven [33]
caprolactone/ footwear
polylactic leather
acid/polyvinyl alcohol
BC/ Coating Adsorption Wastewater [181]
polydoamine/ method photocatalytic treatment
Ti02 properties
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BC/epoxy composites
BC/polylactic acid
BC/graphene
KBC/
polypyrrole/
polyvinyl alcohol
BC/silk sericin
BC/poly- ethylenimine/
platinum KBC/
polyurethane/
polylactic acid BC/chemither momechanical pulp of birch BC/essential oll/polyvmyl- pyrrolidone/
carboxymethyl cellulose/guar gum
BC/poly(L- lactic)
Blending
Blending
In situ method
Impregnation method
Impregnation method
In-situ reduction method Heat
compressive method Blending
Casting method
Melt- spinning techniques
Thermal and dynamic mechanical properties Elongation at break and hydrophobicity Mechanical properties and electrical performance Electrical conductivity
Adhesion and proliferation of cells
Pollutants removal efficiency
Mechanical properties Tear resistance
Antimicrobial, hydrophobicity, and mechanical properties
Viscoelastic properties
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Advanced materials
Flexible food- packaging applications Tissue engineering scaffold
Robust conducting material Tissue engineering Dyeing effluent
treament
Leather
Papermaking
Functional packaging material
Biomaterials
[182]
[132]
[164]
KBC/glycerol BC/non-printed newsprint recycled paper BC/chitosan/
magnetic attapulgite BC/ô-
carrageenan BC/wood- based
nanofibrillated cellulose BC/ polypyrrole/
cotton yarns BC dyed by natural extract BC/chitosan/
metal-organic framework BC/bentonite inorganic BC/ polylactic acid
KBC untreated BC/acrylated epoxidized soybean oil/
polyethylene glycol
Coating methods Blending
Blending
In situ methods Blending
Impregnation method
Impregnation method
Impregnation method
Blending Stacking and compression molding method In situ methods Blending
Mechanical and swelling properties Tensile strength
Adsorption capability
The cells viability and differentiation capacity
Moisture
resistance capacity
Access capacity of electrolyte
Eco-friendly Water stability
Water retention capacity
Mechanical properties
Eco-friendly Elongation at break
Fabric
Papermaking
Environmental and water treatment Scaffolds
Moisture-stable paper
Yarn
supercapacitors Leather
Wastewater treatment
Superabsorbent materials
Biomaterials
Water treatment
Leather
[186]
[187]
[135]
[188]
[30]
[189]
[190]
[191]
[130]
[192]
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Currently, sustainable and environmentally friendly production are key points for the future of the leather industry [3, 28]. Nevertheless, in addition to the incomplete suitableness to perfectly replace all excellent features of genuine leather, almost current alternative leather products that the compositions comprise of only polymers, have poor breathability and stretched biodegradation time after using period. As demonstrated, PU and PVC or fabric synthetic textiles take about 50 years to completely decompose without being recycled or reused [28]. Conversely, if the compositions comprise only purely natural fibers or bio- fillers, these leather products will have poor tensile strength, tear resistance, corrosion resistance and rarely achieve uniformity according to all directions. For instance, BC without incorporating additional reinforcement has demonstrated rapid degradation rates and lacks the strength required [28].
Recently, several significant progress in overcoming these difficulties has been made by rationally combining polymers together and with the bio-fillers.
This approach will simultaneously improve the mechanical properties, environmentally friendly, in particular, supply new opportunities about reduce the production cost for both the leather production companies and agroforestry or food processing companies in managing their waste. Scientists and manufacturers have developed vegan leathers using chicken feathers, cellulose fibers, recycled plastic, orange, apple, pineapple, grape leather (also known as wine leather). The raw materials were crushed, added the binders/polymers, then, molded into the sheet of leather [10, 25]. Adidas, Parley, Spark & Burnish are the brands that have started using ocean plastic waste to create training shoes, sportswear, home decor.
The Paguro brand has used recycled rubber to create modern and luxurious handbags and accessories. Lorica vegan leather is available in a wide range of color options, easy to print, cut, stitch, glue, and a great choice in the manufacture of footwear, clothing, and safe device. Vegetan leather is up to 70-80% more
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