| 1. |
- Akintunde, Moyinoluwa, et al.
(författare)
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Bacterial Cellulose Production from agricultural Residues by two Komagataeibacter sp. Strains
- 2022
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Ingår i: Bioengineered. - : Informa UK Limited. - 2165-5979 .- 2165-5987. ; 13:4, s. 10010-10025
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Tidskriftsartikel (refereegranskat)abstract
- Agricultural residues are constantly increasing with increased farming processes, and improper disposal is detrimental to the environment. Majority of these waste residues are rich in lignocellulose, which makes them suitable substrate for bacterial fermentation in the production of valueadded products. In this study, bacterial cellulose (BC), a purer and better form of cellulose, was produced by two Komagataeibacter sp. isolated from rotten banana and kombucha drink using corncob (CC) and sugarcane bagasse (SCB) enzymatic hydrolyzate, under different fermentation conditions, that is, static, continuous, and intermittent agitation. The physicochemical and mechanical properties of the BC films were then investigated by Fourier Transformed Infrared Spectroscopy (FTIR), Thermogravimetry analysis, Field Emission Scanning Electron Microscopy (FESEM), and Dynamic mechanical analysis. Agitation gave a higher BC yield, with Komagataeibacter sp. CCUG73629 producing BC from CC with a dry weight of 1.6 g/L and 1.4 g/L under continuous and intermittent agitation, respectively, compared with that of 0.9 g/L in HS medium. While BC yield of dry weight up to 1.2 g/L was obtained from SCB by Komagataeibacter sp. CCUG73630 under continuous agitation compared to that of 0.3 g/L in HS medium. FTIR analysis showed BC bands associated with cellulose I, with high thermal stability. The FE-SEM analysis showed that BC fibers were highly ordered and densely packed. Although the BC produced by both strains showed similar physicochemical and morphological properties, the BC produced by the Komagataeibacter sp. CCUG73630 in CC under intermittent agitation had the best modulus of elasticity, 10.8 GPa and tensile strength, 70.9 MPa. [GRAPHICS]
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| 2. |
- Bahrami, Bahador, et al.
(författare)
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Incorporation of Extracted Mucor indicus Fungus Chitin Nanofibers into Starch Biopolymer: Morphological, Physical, and Mechanical Evaluation
- 2021
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Ingår i: Starch. - : John Wiley & Sons. - 0038-9056. ; 73:7-8
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Tidskriftsartikel (refereegranskat)abstract
- Bio-nanocomposites based on starch are reinforced by different percentages of chitin nanofibers (ChNFs) and compatibilized by glycerol. Nanofibers are extracted from Mucor indicus fungus through different chemo-mechanical pretreatments. The mechnical, chemo-physical, and morphological properties of the nanocomposite starch films were evaluated and compared with the unfilled thermoplastic starch (TPS) film. Based on the obtained results, Young's modulus of the film at 5 wt.% ChNFs indicated 239% enhancement compared to the TPS film due to the existence of good interactions between starch and ChNFs. Moreover, the ultimate strength of the reinforced film at 5 wt.% ChNFs and the unreinforced counterpart are found to be 5.5 and 1.74 MPa, indicating 216% improvement; however, the elongation at break of the films decreases from 59.3% to 19.3% by adding 5 wt.% ChNFs. In addition, the moisture absorption of the film decreases after the incorporation of ChNFs. Based on the morphological study, ChNFs increase the roughness of the starch matrix with a homogenous morphology revealing the good dispersion of nanofibers in the TPS film. Finally, the nanocomposite film with 5 wt.% ChNFs show the best properties to employ for bio-film applications.
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| 3. |
- Bátori, Veronika, 1980-, et al.
(författare)
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Anaerobic degradation of bioplastics: A review
- 2018
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Ingår i: Waste Management. - : Elsevier BV. - 0956-053X. ; 80, s. 406-413
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Tidskriftsartikel (refereegranskat)abstract
- Anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW), leading to renewableenergy production in the form of methane, is a preferable method for dealing with the increasing amountof waste. Food waste is separated at the source in many countries for anaerobic digestion. However, thepresence of plastic bags is a major challenge for such processes. This study investigated the anaerobicdegradability of different bioplastics, aiming at potential use as collecting bags for the OFMSW. Thechemical composition of the bioplastics and the microbial community structure in the AD processaffected the biodegradation of the bioplastics. Some biopolymers can be degraded at hydraulic retentiontimes usually applied at the biogas plants, such as poly(hydroxyalkanoate)s, starch, cellulose and pectin,so no possible contamination would occur. In the future, updated standardization of collecting bags forthe OFMSW will be required to meet the requirements of effective operation of a biogas plant.
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| 4. |
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| 5. |
- Bátori, Veronika, 1980-, et al.
(författare)
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Pectin-based Composites
- 2017
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Ingår i: Handbook of Composites from Renewable Materials. - : John Wiley & Sons. - 9781119223795 ; , s. 487-518
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- One third of the cell wall of vascular plants is composed of pectin, which serves as the cementing material for the cellulosic network, behaving as a stabilized gel. Industrially, pectin is produced from juice and sugar production waste. Different sources and extraction conditions result in diversity in characteristics and applications of pectin. Most commonly, pectin is used in the food industry as a gelling and thickening agent and it is favored in the pharmaceutical industry as a carrier for colon-specific drugs. Pectin has good potential to be utilized as a matrix in production of environmentally friendly film packaging as well as biocomposite materials. Pectin is sensitive to chemical reactions and promotes the homogeneous immobilization of cells, genes, and proteins. However, due to limited mechanical properties pectin is not used for structural applications but instead rather for composites in which its biodegradable properties can be utilized. Pectin is often reinforced with hydroxyapatite and biphasic calcium phosphate for bone regeneration and tissue engineering applications. It can also be used as a biosorbent for copper removal from aqueous solutions. Active packaging of nanohybrids composed of pectin and halloysite nanotubes that are loaded with rosemary essential oil is another application of pectin-based composites.
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| 6. |
- Bátori, Veronika, 1980-, et al.
(författare)
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Production of Pectin-Cellulose Biofilms: A New Approach for Citrus Waste Recycling
- 2017
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Ingår i: International Journal of Polymer Science. - : Hindawi Limited. - 1687-9422 .- 1687-9430. ; 2017, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- While citrus waste is abundantly generated, the disposal methods used today remain unsatisfactory: they can be deleterious for ruminants, can cause soil salinity, or are not economically feasible; yet citrus waste consists of various valuable polymers. This paper introduces a novel environmentally safe approach that utilizes citrus waste polymers as a biobased and biodegradable film, for example, for food packaging. Orange waste has been investigated for biofilm production, using the gelling ability of pectin and the strength of cellulosic fibres. A casting method was used to form a film from the previously washed, dried, and milled orange waste. Two film-drying methods, a laboratory oven and an incubator shaker, were compared. FE-SEM images confirmed a smoother film morphology when the incubator shaker was used for drying. The tensile strength of the films was 31.67 ± 4.21 and 34.76 ± 2.64 MPa, respectively, for the oven-dried and incubator-dried films, which is within the range of different commodity plastics. Additionally, biodegradability of the films was confirmed under anaerobic conditions. Films showed an opaque appearance with yellowish colour.
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| 7. |
- Bátori, Veronika, 1980-, et al.
(författare)
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Synthesis and characterization of maleic anhydride-grafted orange waste for potential use in biocomposites
- 2018
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Ingår i: BioResources. - : BioResources. - 1930-2126. ; 13:3, s. 4986-4997
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of the study was to develop a less hydrophilic, and therefore more useful, material from orange waste produced in large quantities by the food industry. A new derivative of industrial orange waste was synthesized via esterification with maleic anhydride. The reaction was confirmed via Fourier transform infrared spectroscopy (FTIR), and the degree of substitution of the hydroxyl groups was 0.39 ± 0.01, as determined by a back-titration method. A major change in physical structure was confirmed by scanning electron microscopy (SEM). The flake-like structure of orange waste changed to a sponge-like structure after the reaction, which involved an increased volume and a reduced density by approximately 40%. The sponge-like structure was represented as an agglomeration of particles with a low specific surface area of 2.18 m2/g and a mean pore diameter of 10.7 nm. Interestingly, the grafted orange waste seemed to become more hydrophobic, which was confirmed by a contact angle test; however, the material absorbed more water vapor. Thermogravimetric analysis (TGA) confirmed a thermally more uniform, though, less heat-resistant material. This work suggests a possible way of utilizing orange waste via synthesizing a renewable material with possible applications as a filler in biocomposites.
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| 8. |
- Bátori, Veronika, 1980-, et al.
(författare)
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The effect of glycerol, sugar and maleic anhydride on pectin-cellulose biofilms prepared from orange waste
- 2019
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Ingår i: Polymers. - : MDPI AG. - 2073-4360.
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Tidskriftsartikel (refereegranskat)abstract
- This study was conducted to improve the properties of thin films prepared from orange waste by the solution casting method. The main focus was the elimination of holes in the film structure by establishing better cohesion between the major cellulosic and pectin fractions. For this, a previously developed method was improved first by the addition of sugar to promote pectin gelling, then by the addition of maleic anhydride. Principally, maleic anhydride was introduced to the films to induce cross-linking within the film structure. The effects of concentrations of sugar and glycerol as plasticizers and maleic anhydride as a cross-linking agent on the film characteristics were studied. Maleic anhydride improved the structure, resulting in a uniform film, and morphology studies showed better adhesion between components. However, it did not act as a cross-linking agent, but rather as a compatibilizer. The middle level (0.78%) of maleic anhydride content resulted in the highest tensile strength (26.65 ± 3.20 MPa) at low (7%) glycerol and high (14%) sugar levels and the highest elongation (28.48% ± 4.34%) at high sugar and glycerol levels. To achieve a uniform film surface with no holes present, only the lowest (0.39%) level of maleic anhydride was necessary.
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| 9. |
- Bidgoli, Hossein, et al.
(författare)
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Effect of carboxymethylation conditions on water binding capacity of chitosan-based superabsorbents
- 2010
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Ingår i: Carbohydrate Research. - : Elsevier - Pergamon. - 0008-6215 .- 1873-426X. ; 345:18, s. 2683-2689
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Tidskriftsartikel (refereegranskat)abstract
- A superabsorbent polymer (SAP) from chitosan was provided via carboxymethylation of chitosan, followed by cross-linking with glutaraldehyde and freeze-drying. This work was focused on an investigation of the effects of monochloroacetic acid (MCAA), sodium hydroxide, and reaction time on preparation of carboxymethylchitosan (CMCS). The CMCS products were characterized using FTIR spectroscopy, and their degrees of substitution (DS) were measured using conductimetry and FTIR analysis. The highest DS value was obtained when the carboxymethylation reaction was carried out using 1.75 g MCAA and 1.75 g NaOH per g of chitosan in 4 h. The water solubilities of the CMCS products at various pHs were also evaluated, and the results indicated a significant impact of the reaction parameters on the solubility of CMCS. The CMCSs with the highest DS value resulted in SAPs having the highest water-binding capacity (WBC). TheWBCof the best SAP measured after 10 minexposure in distilled water, 0.9% NaCl solution, synthetic urine, and artificial blood was 104, 33, 30, and 57 g/g, respectively. The WBC of this SAP at pH 2–9 passed a maximum at pH 6.
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| 10. |
- Dumitrescu, Delia, et al.
(författare)
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Orange Waste Films as a Raw Material for Designing Bio-Based Textiles : A Hybrid Research Method
- 2022
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Ingår i: Materials Science Forum. - Switzerland : Trans Tech Publications, Ltd.. - 0255-5476 .- 1662-9752. ; 1063, s. 3-14
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Tidskriftsartikel (refereegranskat)abstract
- Bio-based textiles are an emerging area of cross-disciplinary research, involving material science and design and contributing to textile sustainability. An example of a bio-based textile is an orange-waste film, which is plant-based and biodegradable and possesses mechanical properties which are comparable to some commodity plastics. The research project presented in this article aimed to explore orange-waste film as a new material for textile and fashion design and highlights how experimental co-design processes and innovation involving orange waste film as a textile material adds a new layer of material understanding to both textile design and technology-driven material research. Material-development methods were used to develop the orange-waste film, as were textile design methods with a focus on surface design. The results show that material variables such as tensile strength and elongation are dependent on the grinding process and drying temperature used for the raw material, as these determined the quality and durability of the orange-waste film and its applicability to the field of textile design. The use of orange waste in the creation of textiles opens up more ways of thinking about and working with materials, and orange waste could become a desirable raw material for textile design on the basis that it introduces certain aesthetic and functional possibilities through its visual and tactile expression and material behaviour, in addition to defining methods of producing textiles.
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