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The combination of marine polysaccharides, chitosan (CS), that is signified as bio-polymeric substance with environmentally benign magnetite (Fe3O4) has led to an ever expanding of its applications. Such modification tends CS to be superparamagnetic photocatalyst and could be recoverable, recyclable and a sustainable material. Herein, Fe3O4 reinforced CS that is so-called Fe3O4@CS nanocomposite was fabricated in different proportions (Fe3O4@CS (2:1), (1:2) and (1:3) using simple co-precipitation route. The characteristics of the prepared samples were investigated to explore their structure and morphology using X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and vibrating sample magnetometer. Thereafter, the polymer-based photocatalyst was used as a Fenton's reaction for oxidation of Synozol Red KHL dye in aqueous media. The effects of several operational parameters on the photocatalytic performance are also described. In addition, the catalyst recyclability is achieved to attain its activity after 6th cycles with high removal efficiency. The process optimisation using response surface methodology is conducted and the optimal operational conditions recorded are 465 and 2 mg/L for H2O2 and Fe3O4@CS nanocomposite, respectively at pH 2.0. The dye removal reached to a complete mineralisation (100%) within 30 min of irradiance time. Kinetic data revealed the oxidation system follows the first-order reaction kinetic and the thermodynamic parameters confirmed the reaction is endothermic and non-spontaneous in nature. The reaction confirmed its sustainability since it is applied using solar energy as an economic source with 100% removal within 30 min in the solar reactor. [ABSTRACT FROM AUTHOR]

The aim of this work was to produce biodegradable film based on polyvinyl alcohol/vanadium pentoxide (V2O5)/grapefruit peel powder (GF) (PVA/GF/V2O5). Grapefruit peel powder and V2O5 effects on the physicochemical/structural properties of the films was evaluated. The properties like, solubility, thickness, antioxidant activity, humidity, water vapor permeability (WVP), color indices, FTIR, TGA, SEM and XRD tests were investigated. According to the results, increasing of grapefruit peel powder led to an increase in the color indices (a and b) and thickness of the films, and on the other hand, a decrease in the solubility and L index was observed with the addition of V2O5 nanoparticles in the samples. Addition of V2O5 to the film increased the index a and b of the samples. The antioxidant properties of the samples increased with the addition of grapefruit peel powder and V2O5. The electrostatic interaction between polyvinyl alcohol, grapefruit peel powder, and V2O5 nanoparticles was confirmed by FTIR. According to the SEM images, films containing grapefruit peel powder and nanoparticles have a granular heterogeneous film. The TGA results showed that the thermal stability of films containing grapefruit peel powder and nanoparticles was better than the control sample, and the results obtained from XRD showed that with the addition of grapefruit peel powder, there were slight changes in the intensity of the peaks, and addition of V2O5 led to the increasing of peak intensity, which has the highest percentage of impact on the film's crystallite structure. [ABSTRACT FROM AUTHOR]

Alginate, a naturally sourced bio-polymer derived mainly from brown seaweed, has gained incredible attention due to its versatile properties and wide range of applications. This review outlines alginate regarding sources, extraction methods, classifications, and critical characteristics. The critical development of alginate, focusing on its application in 3D bioprinting in fields such as vascular tissue formation, bone printing, and cartilage printing, has been discussed. Recent trends regarding the application of alginate in different sectors, from cosmetic textiles to wastewater treatment, wound dressing, and preparation of intelligent materials, have also been probed. The techniques used, benefits, and limitations form the discussion of each application. In addition, future alginate perspectives are discussed by considering current research with potential innovations that can expand its utility. Particular attention is devoted to the promising role of alginate in these emerging technologies that hold promise for radical changes in many industries due to its biocompatibility, biodegradability, and unique physicochemical properties. This review seeks to lay down basic knowledge on alginate by synthesizing the state of the art and, in this way, brings out the gaps that might inspire further studies and development in this dynamic field.Article Highlights: The physicochemical and biological properties of alginate are described, along with the extraction process. It reports the application of alginates in 3D bioprinting, cosmetic textiles, smart materials with techniques and limitations involved. Future perspectives of alginate are mentioned. [ABSTRACT FROM AUTHOR]

Introduction Consumer demand for healthy food free of chemical preservatives and environmental concerns with plastic packaging environments are analyzed, which can be replaced by aquatic environments that can be contaminated, for the development of bio-based packaging materials. Natural polymers have the ability to be biodegradable due to the presence of oxygen or nitrogen atoms in their main polymer chain compared to the dominant carbon-carbon bonds in fossil-based polymers. Among the various biopolymers used to prepare multilayer films, polysaccharides are considered as the main components of the film due to their abundance and non-toxicity. These films generally have good mechanical strength, moderate physical properties, and most importantly, are edible and easily degradable. However, they are very brittle and hydrophilic, and these properties are undesirable in food packaging applications. Among polysaccharides, agar, commercially extracted from seaweed, is one of the most common and widely studied base materials. Agar is insoluble in cold water, but soluble in water at 90-100°C. When making an agar film, the solution and casting surface must be kept above the agarose gel setting temperature to avoid premature gelation. Compared to other biopolymers, agar is more stable at low pH and high temperature. This thermoplastic and biocompatible polysaccharide creates films with high mechanical strength, transparency and moderate barrier properties to carbon dioxide and oxygen, and most importantly, it is edible and easily biodegradable. Mixing agar with other polymers such as polyvinyl alcohol (PVA) and polyethylene improves the mechanical, thermal and biodegradability properties of bio composites. The main goal of this study is to make biofilms for use in packaging industries with agar polymer extracted from macroalgae species Acanthophora sp. Agar was extracted by sodium hydroxide/heating method and the film was prepared in combination with industrial polymer PVA and glycerol. Materials and Methods To make biofilms based on agar polymer, firstly, optimization of agar polymer extraction from macroalgae species Acanthophora sp. was done by sodium hydroxide/heating method, and in the next step, total phenolic compounds and the amount of soluble protein in extracted agar were measured. In the next step, glycerol with 30% by weight was used as a softener and PVA polymer with a weight ratio of 25% to the dry weight of agar powder was used to make bio composite by solvent casting method, in order to strengthen the mechanical and physical properties of bio composites. Characterization tests of the prepared composites included: XRD, FTIR and Tensile test. Laboratory tests include; The percentage of solubility in water and degree of swelling for all bio-composites were evaluated to determine the optimal physical properties of bio-films. Results and Discussion: he results showed that; 15% extraction efficiency was obtained for sodium hydroxide/heating pretreatment method. The results of measuring the amount of total phenolic compounds in agar solution extracted by sodium hydroxide/heating method showed that the number of phenolic compounds in agar solution was 0.077 ± 0.004 in terms of mg of gallic acid/g of agar. The results of measuring the amount of protein in extracted agar determined by Bradford method showed that the agar solution contains 0.040 ± 0.019 mg/ml of protein. A decrease in the swelling rate and an increase in the water solubility of the agar bio composite occurred with the addition of glycerol and PVA polymer. The results of the tensile test showed that the addition of glycerol, a small hydrophilic molecule, to the agar bio composite leads to a decrease in the elastic modulus and an increase in flexibility. Adding PVA to agar/glycerol biofilm caused a decrease in the amount of elastic modulus and percentage of flexibility, which is the main factor of this phenomenon, the low values of elastic modulus and flexibility of PVA. Finally, the results confirm the use of these coatings for packing fruits and vegetables in tropical regions by increasing their shelf life for at least 5 days at 25°C.

Paddy straw is often burnt in the fields or disposed of in ways that cause extensive environmental pollution. The present study focused on using paddy straw in bio-compostable composites fabricated with polyvinyl alcohol (PVA) and thermoplastic starch blends as a matrix. Locally available paddy straw was chopped, cleaned and treated with 15% NaOH solution for four hours. The alkali treatment produced changes in the crystal structure and surface morphology of the paddy straw. Then, it was dispersed in blends of PVA and starch solutions containing polyethylene glycol (PEG200) as plasticizer. The PEG200 acted as both plasticizer and compatibilizer, as evidenced by the single glass transition peak and the lower melting point of the film cast from these blends. These composite films had higher thermal stability, increased tensile strength, but also flexibility. These properties were associated with structure development with strong hydrogen bonding interaction between the paddy straw and PVA-starch blends, which was supported by results of characterization studies. [ABSTRACT FROM AUTHOR]

Coir is a lignocellulosic natural fiber derived from the coconut's husk, an abundantly found fruit or nut worldwide. This fiber has some unique characteristics, such as its resistance to seawater, microbial attack, high impact, etc. But its low thermal conductivity or high thermal insulating property makes it suitable for being used as insulators in civil engineering sites. On the other hand, the sustainability of a material depends heavily on its environmental impact of the material. For making sustainable materials like biocomposite, there are no options other than using polymers derived from natural renewable sources. Polylactic acid(PLA) is an example of those types of material. And these materials are often being reinforced by fibers like coir for various reasons including improving mechanical properties, reducing the cost of the material, and improving the material's sustainability. Many coir-reinforced sustainable biopolymer composites have already been produced in many pieces of research, which will be discussed in this paper, along with the chemical and physical structure of coir fiber. In addition, this paper will try to focus on the insulating properties of coir and coir-reinforced composites while will also compare some properties of the composites with some commonly used materials based on different parameters to show the suitability of using the coir fiber in heat-insulating applications and to produce sustainable biocomposite materials.

Natural edible microcapsules, were developed to improve the shelf life of Zanthoxylum bungeanum. Antimicrobial peptides, extracted from seeds of Sichuan pepper corn by ultrasound and microwave assisted extraction were encapsulated with nisin using water-in-oil-in-water (W/O/W) microencapsulation technique. Prepared microcapsules exhibited maximum encapsulation efficiency (ω %) of 30.20 at 3:1 ratio of extracted protein (EP) to gum Arabic (GA). After characterization, microcapsules were applied to Sichuan peppers by coating them during 10-days storage. Meanwhile, antimicrobial activity, total phenolic content (TPC), total flavonoid content (TFC) and radical scavenging activity (%) of treated pepper samples were evaluated; demonstrating that S3 and S4 microcapsules provided maximum antimicrobial activity (89.75 and 81.33 %), TPC (543.56 ± 3.87 and 481.40 ± 6.54 GAE/g), TFC (266.02 ± 2.64 QE/g and 306.96 ± 3.87 QE/g) and DPPH radical scavenging activity (78.06 ± 2.87 and 76.52 ± 1.67 %), respectively. Hence, S3 and S4 micro-capsules can be successfully employed as edible coating packaging to improve quality and shelf life of pepper. • Ultrasound and microwave assisted extraction provided maximum yield of antimicrobial peptides. • Peptides encapsulated with nisin using water-in-oil-in-water microencapsulation technique. • Natural edible microcapsules improved the shelf life of Zanthoxylum bungeanum. • This approach highlights a green initiative in food preservation techniques. [ABSTRACT FROM AUTHOR]

Considering the ubiquity and high toxicity of Cr(VI) species for destroying a sustainable environment, developing energy-efficient method for capturing and detoxifying chromium [Cr(VI) → Cr(III)] is imperative. Herein, ferrocene (Fc) was combined with carboxymethyl cellulose (CMC) and polyethyleneimine (PEI) for Cr(VI) remediation. Fc species possessed reversible redox behavior and low ionization potential, yet it faced challenges with conductivity and stability. Results revealed that, PEI facilitated the binding of Fc within the CMC through electrostatic interactions or coordination bonds, ensuring the good dispersion and stability of Fc. When applied in the electrochemical adsorption of Cr(VI), the combination created a synergistic effect. The presence of Fc and PEI boosted the electrochemical performance by providing faster electronic and ionic transportation, higher specific capacitance coupled with improved electrode-electrolyte interactions, leading to a higher Cr(VI) adsorption capacity over CMC/PEI/Fc (280.5 mg/g) compared to those over CMC and CMC/PEI. The interactions between the Cr(VI) and electrode included the electrosorption, electrostatic interaction of protonated PEI and oxidized Fc species. When the electric field was reversed, the Cr(VI) was electrostatic repulsed and electrocatalytic reduced to Cr(III) with a reduction rate of 85.4 %. This work promoted the development of effective electrosorption materials suitable for complete Cr(VI) removal and detoxification. [Display omitted] [ABSTRACT FROM AUTHOR]

The rising water pollution by pesticides, pharmaceuticals and dyes is a major health issue calling for advanced remediation methods such as photocatalysis with titanium dioxide (TiO2), yet the use of TiO2 displays issues of aggregation, mass loss, recovery, and reusability. These issues have been recently solved by synthesizing biopolymer-supported photocatalysts using cheap, biodegradable and safe biopolymers such as chitosan, alginate, cellulose, cyclodextrin, guar gum and starch. Here we review biopolymer-supported TiO2 photocatalysts for the removal of organic compounds, with focus on preparation methods, photo and chemical stability, reusability, and adsorptive capacity. We discuss applications of immobilized photocatalysts at the industrial scale. [ABSTRACT FROM AUTHOR]

Nowadays research in the biopolymers is prominent area for research in medical fields. The metallic implants are used in many numbers for the orthopaedic surgeries. But some unavoidable issues are arising after surgeries like stress-shielding, osteogenesis imperfection, etc. To overcome such issues, re-surgery is only one painful option available for the patient. Sometimes, this option is not feasible for the weak and old patients, which results in increased life risk in such situation. Hence, a biopolymer may be the best solutions to eliminate such problems. Polyether ether ketone (PEEK) and hydroxyapatite (HA) are having biocompatible characteristic with different mechanical properties. Hence in this paper, three different compositions of PEEK-HA are considered and the composites were prepared using compression moulding technique. To compare the mechanical properties for different compositions of PEEK-HA, the porosity and tensile strength were calculated. Unlike the other techniques, the fracture toughness was evaluated through J-integral method to ensure the matching of the cracking phenomenon with the human bone. Tribological properties, for example, wear resistance and plasticity index for all compositions of PEEK and HA were executed in both static and dynamic mode. The result reveals that PEEK5HA can be used for the possible bone replacement. [ABSTRACT FROM AUTHOR]

This examination explains the utilization of bio-polymer powder for clayey soil enhancement. The article concentrates around examining the strength attitude of the clayey soils built up with homogenous bio-polymer. Carboxy methyl cellulose was determined as bio-polymer material to build up the normal soft clayey soil. The biopolymer has been added to the soil with two separated rates (0.5 and 3%) by total weight of soil. Different tests were carried out to consider the impact of utilizing this polymer as a balancing out specialist on the geotechnical properties of soil. It was estimated that as the bio-polymer content expands in the soil, the specific gravity decreases, while the optimum water content (OMC) is expanded. The results showed different effects on Atterberg’s limits; by increasing the liquid limit(L.L) and plasticity index(P.I) while the plastic limit decrease. The tests additionally mirrored a huge improvement in the unconfined compressive strength (UCS) of the treated soils. With the increment in biopolymer content, the consolidation index (Compression index Cc and recompression index Cr) decrease.

Biomimetic is the name of the approach that seeks sustainable solutions to the problems, taking the perfect functioning of nature for millions of years. The interest shown in biomimetic surfaces, inspired by multi-scale structures found in many plants and animals, is increasing day by day. Especially the unique wettability properties of the lotus leaf and rose petal. In this study, inspired by the structures of lotus leaf and rose petal, using the soft casting method with dental bio-polymer materials, structures with pillar dimensions of micron (µm) and millimeter (mm) were produced. These structures are replicated from two commercial products with different pillar lengths and different pillar shapes, mushroom and conical needle tips. Surface topographies of the replicated final products were analyzed by optical and stereo microscopes. Contact angles were tested to examine the wettability properties of the surfaces. According to the microscope results obtained, the demolding process, which is the riskiest step of the replication process, was successfully passed thanks to soft casting. Contact angle analysis showed that different pillar lengths and different pillar shapes changed the wettability properties of the replicated final product. The replicated mushroom-shaped micron-scale pillar structures exhibited a rose-petal effect and hydrophobic properties (approximately 1000) with only a single-scale configuration, while conical needle-shaped pillars of millimeter (mm) scale did not show any specific wetabilitty property.

The schematic representation is showing the bending behavior of the SAA and CLC-SAA. The strip for pH 1 (acidic) and pH 14 (alkaline) on the left side. On the right side bending behavior of SAA and CLC-SAA for pH 7. [Display omitted] • Integrated sodium alginate hydrogel with cholesteric liquid crystal for pH sensing. • Extensively investigated the hydrogen bonding mechanism employed for pH sensing. • Demonstrates exceptionally quick bending responses in the millisecond range. • Highly adaptable for applications in soft robotics, the food industry, and various other fields. The present work developed a novel type of soft actuator capable of pH sensing, named CLC-SAA (Cholesteric Liquid Crystal-Infused Sodium Alginate Actuator). This actuator is created by combining sodium alginate hydrogel with cholesteric liquid crystal via an evaporation method. Our study validates the actuation mechanism by observing shifts in the vibrational stretching of carboxylic group bonds through FTIR spectroscopic investigations. Leveraging the weak acidic nature of carboxylic acid in sodium alginate hydrogel, this actuator offers distinct advantages. The CLC-SAA exhibits remarkably rapid bending responses, with fast responses observed of the order of 4 sec to 0.4 sec and bending angles as low as 3° to as high as 18°. This responsiveness is consistent across a wide range of pH values, making it highly adaptable and valuable for applications in medical, chemical, and bio-robotics fields. Such actuation holds significant promise for various applications due to its adaptability and wide-ranging capabilities. [ABSTRACT FROM AUTHOR]

With the current state of transportation infrastructure in the US, improvements need to be made to the construction materials to obtain a longer service life. Polymer modified asphalts are one solution for asphalt pavements to significantly improve the service life. If the polymers used for the modification of asphalt are derived from bio-renewable resources, they can have a vast contribution on increasing the sustainability of asphalt pavements. This research utilizes a master batching procedure in which a poly(styrene–butadiene–styrene) (SBS) polymer concentrate is formed before diluting and blending in a soybean derived polymer, sulfur, and functionalized soybean oil. The objective was to study the effects of blending duration on the rheological and chemical properties of the modified asphalt. Samples were taken periodically over 72 h to measure these properties. The results show that at short blending durations, the use of SBS and the bio-polymer causes aggregation of the polymers resulting in a heterogeneous morphology with reduced elastic performance. However, at longer blending durations the performance of the blends containing both polymers match or exceed the blends without the bio-polymer. [ABSTRACT FROM AUTHOR]

Impacts of Marine Plastic Debris (MPD) on marine ecosystems are among the most critical environmental concerns of the past three decades. Virgin plastic is often cheaper to manufacture than recycled plastics, increasing rates of plastic released into the environment and thereby impacting ecosystem health and functioning. Along with other environmental effects, MPD can serve as a vector for marine hitchhikers, facilitating unwanted organisms’ transport and subsequent spread. Consequently, there is a growing demand for more eco-friendly replacements of conventional plastic polymers, ideally with fit-for-purpose properties and a well-understood life cycle. We enriched polybutylene succinate (PBS) with three different concentrations of oyster shell to investigate the dynamics of biofouling formation over 18 weeks at the Nelson Marina, Aotearoa/New Zealand. Our study focused on oyster shell concentration as a determinant of fouling assemblages over time. While generally considered as a waste in the aquaculture sector, we used oyster shells as a variable of interest to investigate their potential for both, environmental and economic benefits. Using bacterial 16S and eukaryotic 18S rRNA gene metabarcoding, our results revealed that following immersion in seawater, time played a more critical role than substrate type in driving biofouling community structures over the study period. In total, 33 putative non-indigenous species (NIS) and 41 bacterial families with putative plastic-degrading capability were detected on the different substrates. Our analysis of NIS recruitment revealed a lower contribution of NIS on shell-enriched substrates than unadulterated polymers samples. In contrast, the different concentrations of oyster shells did not affect the specific recruitment of bacterial degraders. Taken together, our results suggest that bio-based polymers and composites with increased potential for biodegradability, recyclability, and aptitude for the selective recruitment of marine invertebrates might offer a sustainable alternative to conventional polymers, assisting to mitigate the numerous impacts associated with MPD.

The present study deals with the incorporation of different ratios of alkali-treated coir fibres (CF) and pineapple leaf fibres (PALF) in polylactic acid (PLA) hybrid composites. Developed hybrid composites are characterized in terms of mechanical, morphological, thermal and physical properties. Mechanical characterization revealed that alkali-treated C3P7 hybrid composites (CF:PALF = 3:7) showed highest tensile strength (30.29 MPa) and young’s modulus (5.16 GPa) among all hybrids composites, whereas C1P1 (CF:PALF = 1:1) showed highest impact properties. Scanning electron microscopy (SEM) justified the consequence of alkali treatment on fibre-matrix adhesion. Thermal analysis revealed that C1P1 and C7P3 (CF:PALF = 7:3) having a higher thermal stability and char content due to the higher content of lignin in CF. Remarkably, the coefficient of thermal expansion (CTE) of treated hybrid composites displayed lesser values than untreated hybrid composites. The physical tests revealed that C3P7 showed highest water absorption (WA) and thickness swelling (TS) though after treatment the WA and TS values get reduced. Overall results indicated that treated CF/PALF/PLA hybrid composites possess enhanced mechanical, thermal and physical properties with lowered CTE over untreated CF/PALF/PLA hybrid composites. The success of these findings results sustainable and degradable hybrid composites for different outdoor and food packaging-based applications.

A low-velocity impact characterisation of a sustainable sandwich panel based on upcycled bottle caps as circular honeycomb is conducted. The recycled core aims to develop an alternative route of reusing waste bottle caps disposed in landfills. Ecological alternatives to skin (recycled PET foil) and adhesive (bio-polyurethane) are also compared with classic components (aluminium skin and epoxy polymer). A low-cost reinforcement (cement particles) is also proposed to enhance the mechanical strength of the panel. The samples are tested at several levels of impact energy, according to the type of skin, to observe their effect on mechanical behaviour. Metal skins achieve higher impact loads and energy absorption compared to PET foil. The bio-adhesive leads to a similar or enhanced maximum impact load and energy absorption compared to the epoxy adhesive. Specific properties highlight the promising performance of the bio-based adhesive with aluminium skins, reaching increments of up to 378%. The cement increases the maximum load and reduces the duration of the impact event, leading to lower energy absorption. The unreinforced epoxy polymer shows a visible adhesive peeling off from aluminium skin, while particle inclusions lead to reduced overall delamination. Biopolymer exhibits marginal adhesive debonding and stable deformation, revealing a progressive failure. In general, PET samples show core shear failure due to rupture of the skin. Crack propagation in PET samples made with biopolymer adhesive is reduced at lower energy levels. The results evidence the promising application of bottle caps in a more sustainable honeycomb core to build eco-friendly structures. [ABSTRACT FROM AUTHOR]

Owing to increasing environmental concerns and growing demands for food quality maintenance, biodegradable active packaging is emerging on the market to overcome the challenges faced by traditional plastic packaging. Pectin, with characteristics of low price, non-toxic and good polymerization, is an ideal material for active food packaging. This review offers the current state of studies on pectin-based active packaging. Three different film formation methods were critically summarized. Physical properties of pectin-based packaging were systemically characterized regarding various pectin structural conformation. Furthermore, preservation behaviors and related mechanisms were fully illustrated to exhibit the outstanding advantages of pectin-based active packaging in food preservation. Pectin-based active packaging can be developed in either wet or dry processes. Wet process contains casting method leading to compact surface morphology and spraying method requiring specialized equipment, while dry process mainly refers to extrusion method with higher efficiency and meets the needs at commercial production. Physical properties of packaging including mechanical, hydrophobic and thermal characteristics are enhanced by modification of pectin conformation or incorporation with bio-polymers, overcoming the weaknesses of pure pectin packaging, such as thermal instability and strong hydrophilicity. After being functionalized with active compounds, pectin-based packaging with great antimicrobial, antioxidant and barrier properties is quite suitable for food preservation. Pectin-based packaging has great advantages to extend shelf-life of food by retarding lipid oxidation, inhibiting microbial growth, controlling water movement, etc. As a result, pectin-based active packaging with great physical and functional properties, has promising prospects in food preservation. • The main methods of pectin packaging preparation are casting, spraying and extrusion. • Film physical and functional properties are modified by incorporating other polymers. • Pectin active packaging can maintain quality and extend shelf-life of packaged food. • Pectin conformation exerts influences on film properties and preservation behaviors. • Pectin-based active packaging has a promising prospect in food packaging industry. [ABSTRACT FROM AUTHOR]

Sustainability and circular economy cover the principles of designing out waste and pollution, keeping products and materials in use, and regenerating natural systems. Due to global trends (eg. increasing e‐waste and material consumption) and global sustainability goals also electronics industry has to consider how to increase sustainability in its products, operations and service models. VTT has demonstrated sustainable electronic solutions by developing bio‐based and renewable material processing, by utilizing high‐speed printing and hybrid integration manufacturing processes, and by evaluating environmental impact of electronic systems and devices. This paper covers the different aspects of sustainability and highlights solutions demonstrated at VTT. [ABSTRACT FROM AUTHOR]

This study investigates the tensile and compressive failure behavior of a single-lap joint of green composites obtained by resistance welding. The green composites composed of poly (lactic)acid (PLA) and bamboo fiber were fabricated in a hot compression by the film-stacking method. The different heating elements namely polypyrrole (conductive polymer), carbon fiber (CF) fabric, and stainless steel (SS) mesh were used to perform the resistance welding of nonconductive green composites. The heating time (30, 60, and 90 s) and the percentage of overlapping area covered by the heating element (35, 65, and 100%) were the other two welding parameters considered for experimental investigation. The effect of welding parameters on tensile and compressive failure loads was experimentally investigated through a full-factorial experimental design. The load vs. displacement and failure behavior of the welded specimen under different conditions was extensively investigated. The statistical analysis of the experimental data was performed to find the relative significance of the welding parameters. The type of heating element was found to be the most significant parameter as it has maximum statistical contribution in both tensile and compressive failure loads. The tensile and compressive failure loads were improved by 31% and 63% when CF fabric was used as a heating element as compared to the SS mesh heating element. Similarly, failure loads obtained by using CF fabric were improved by 187% (tensile) and 323% (compressive) when compared one-on-one with polypyrrole heating element.

Kafirin-based films can be a potential alternative to petroleum-derived plastic and is an essential step towards environmental waste management. This study presents kafirin as a bio-polymer with the potential for making films by using a solution casting technique. Kafirin films with varying concentrations of polyethylene glycol (400), triacetin and triethyl citrate were cast. The interaction of kafirin by the plasticizer was confirmed by FTIR spectra studies. The effect of plasticizers on the crystallinity of the polymers has been studied by using the XRD technique. The change in glass transition temperature (Tg) of the films was analysed using differential scanning calorimetry. The thermal stability of films was ascertained by TGA. The measurement of breaking strength and elongation at break helped in studying the effect of plasticizers on the mechanical properties of the films. The water permeability and water contact angle test have been carried out to understand the barrier properties that are necessary for food-grade applications. By comparing test results, it was found that various plasticizers are suitable to be used with kafirin depending on the end-use application. [ABSTRACT FROM AUTHOR]

The high cost of carbon fibre continues to limit its use in industries like automotive, construction and energy. Since the cost is closely linked to the precursor, considerable research has focussed on the use of low-cost alternatives. A promising candidate is a composite fibre consisting of blended cellulose and lignin, which has the added benefit of being derived from sustainable resources. The benefits of blending cellulose and lignin reduce some of the negative aspects of converting single component cellulose and lignin fibres to carbon fibre, although the production from such a blend, remains largely underdeveloped. In this study, the effects of stabilisation temperature and the stabilisation process of the blended fibres are explored. Moreover, the viscoelastic properties of the cellulose-lignin fibre are investigated by DMA for the first time. Finally, the cause of fusion in the stabilisation is adressed and solved by applying a spin finish. [ABSTRACT FROM AUTHOR]

The meat industry produces a lot of waste, which contains large amounts of the organics and nutrients. Animal by-products have potential for biomaterial extraction. The use of bio-material, which can be obtained from plant sources, microorganisms, agricultural, and animal waste are nowadays favored because of their compatible, cost-effective, and low-risk for removal of pollutants, compared to chemical and physical methods. In this study, a biopolymer from meat by-product extracted by methanol-chloroform and characterized by FTIR, GC–MS, HPLC, and SDS-PAGE analyzes. The extracted biomaterial was useful in water desalination by calcium carbonate precipitation and heavy metals removal, which was confirmed by FTIR and ICP analyzes. The extracted biomaterial also has antibacterial properties against Pseudomonas aeruginosa and Escherichia coli without toxicity to human blood cells, which can make it useful in industries such as its application in fish ponds. [ABSTRACT FROM AUTHOR]

By grafting polysaccharides backbone of biopolymer (alginate) on synthetic polymer nanocomposite chains (PAMPS/NiFe2O4) to remove methylene blue and toxic heavy metal (Cu2+) from aqueous solutions, a superadsorbent was prepared. Using FTIR, TGA, X-ray diffraction, TEM, and SEM studied the structures of native and grafted alginate hydrogels. Adsorption experiments have been optimized using RSM/CCD response surface methodology and analyzed as a pH solution and adsorbent dose function. The initial concentrations of metal and dye, temperature, and contact time were also discussed and isothermal, thermodynamic adsorption, and kinetic theoretical constants were calculated as well. Results revealed that alginate grafted nanocomposite PAMPS/NiFe2O4 enhanced the proportion of methylene blue (MB) color removal up to (98.32%) and metal ion discharge (83%). The optimum cationic dye MB and Cu2+ ions adsorption capability were acquired at pH (5.75 and 4) and temperature (318.15 K) respectively. For both MB dye and Cu2+ ions, the pseudo-2nd-order model has effectively defined the adsorption kinetics and the Freundlich model could precisely explain adsorption isotherms than the Cu2+ Langmuir adsorption model, while the adsorption of MB dye showed a greater presence for both Freundlich and Langmuir designs. MB dye and Cu2+ ions have recorded the highest adsorption capacity of 275.6 and 22.81 mg/g respectively; indicating an efficient separation of adsorbent from aqueous solutions for both cationic dyes and toxic heavy metals. [ABSTRACT FROM AUTHOR]

The extensive discomfort in the expulsion of toxic pollutants even at mild concentrations has demanded the need for prompt methods for the evacuation of dyes and heavy metals. The effective method for depuration of dye from the effluent is by sorption. Chitosan is a bio‐polymer which is gaining an increasing interest as one of the sorbents. It was obtained from the crab shells by undergoing several chemical processes and used as an adsorbent for dye, metal removal and also for pharmaceutical purposes. Cross linking it with other co polymers will increase the capacity of adsorption to a maximum level. Fish scales are considered to be a major waste in the food industry and since it takes a long time for decomposing it is considered to be one of the pollutants. Hence it is utilised by converting it into activated carbon by preliminary treatment and into a muffle furnace. The obtained activated carbon is combined with chitosan by using a cross linker and utilised for adsorption mechanism. To analyse the effect of chitosan cross linked with activated carbon obtained from fish scales in adsorption of dye Reactive Blue 9 (RB9) to evaluate the adsorption studies, kinetics, mass transfer studies, thermodynamics of the bio adsorbent. [ABSTRACT FROM AUTHOR]

[Display omitted] • The palygorskite-based aerogels had a hierarchically porous structure. • The aerogels showed an excellent selective adsorption capacity. • The adsorption to malachite green and sunset yellow was 2008 mg/g and 976 mg/g. • The aerogel had stable regenerative adsorption capacity. It is a challenge to develop high-efficiency, easy-recyclable adsorbents for the removal of dyes from environmental waters. Herein, we report the construction of two types of palygorskite (Pal)-polymer aerogels with distinctive hierarchically meso − microporous structure, which different polymer species-sodium alginate (SA) and chitosan (CS) through the sol-gel method, cross-linking, and freeze-drying, for the removal of dye pollutants from water. A hierarchical porous structure of aerogel accelerates the diffusion of dye water. Notably, this developed strategy enables selective dye adsorption by tuning the polymer and component contents in the Pal-polymer aerogel. Indeed, the maximum adsorption capacity of the Pal-SA composite aerogel for malachite green (cationic) dye reached 2008 mg/g and that of the Pal-CS(Fe3+) composite aerogel for sunset yellow (anionic) reached 976 mg/g. In addition, the composite aerogels can be regenerated many times without significant loss of effectiveness. This work provides a new concept and strategy for dye waste-water treatment. [ABSTRACT FROM AUTHOR]

Cellulose aerogel (CA) isolated from tea stem wastes (TSW) is a good fire retardant and heat insulator, environmentally friendly, thermally stable and highly porous material with a network structure. These outstanding properties have attracted a huge interest in the materials world. In this study, firstly, following delignification and removing hemicellulose, pure raw cellulose was isolated using TSW, hydrogel form of cellulose was prepared by regeneration of cellulose solution, and then, the final product (CA) was produced via freeze-drying. The data results showed that the aerogel had a three dimensionally network structure. Moreover, it can be deduced that thermal durability of the studied CA could be effective because of its fire retardant and heat insulating property. In addition, the production process of CA is easily available at low cost and sustainable. [ABSTRACT FROM AUTHOR]

Lithium ion conducting solid polymer electrolyte based on carboxymethyl cellulose (CMC) complexed with lithium tetrafluoroborate was prepared by using solution cast technique. Ionic conductivity was measured using ac impedance analyzer and observed as 8.2 × 10−6 S cm−1 at room temperature. For further enhancement in the conductivity, plasticizer was introduced and it reached up to 3.7 × 10−3 S cm−1 at room temperature. Structural characterization was performed by using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscope technique. XRD results show the amorphous nature of the electrolyte film. FTIR spectroscopic analysis confirmed the complexation of the salt and plasticizer with the polymer matrix. Differential scanning calorimetry was used to determine the glass transition and melting temperatures of pure CMC and CMC-based polymer electrolyte film. [ABSTRACT FROM AUTHOR]

Chemical stabilization is extensively employed to enhance the physical and mechanical properties of problematic soils. For instance, there are various types of chemical additives in liquid and powder forms. One of the potential bio-polymer stabilizer is Xanthan Gum which has widely been employed due to the environmental issues and the effect of land desertification. This research is devoted to studying the effect of Xanthan Gum on the strength improvement of lateritic soil. The lateritic soil sample is provided from the hilly area at Universiti Teknologi Malaysia. The physical and engineering tests on untreated and treated samples were conducted according to BS1377:1990. The Maximum Dry Density (MDD) and Optimum Moisture Content (OMC) were determined using the compaction test results. Then, MDD and OMC are used for the Unconfined Compressive Strength (UCS), and direct shear tests sample preparation. The lateritic soil was mixed with different percentages of Xanthan Gum including 0.5%, 1.0% and 1.5% of the soil mass and cure for 3, 7 and 14 days. It was found that the UCS and direct shear strength parameters of cohesion and internal friction angle improve with the curing duration. The Field Emission Scanning Electron Microscopy (FESEM) shows the generation of new cementitious products as a result of the reaction between Xanthan Gum and lateritic soil. New generated products fill the porous areas within the soil particles, leading to a continuous soil structure. Therefore, stronger and denser soils are provided as the pore space is reduced. [ABSTRACT FROM AUTHOR]

Lanthanum (Rare earth metal) doped CuS (La@CuS) at different compositions (0%, 1%, 3% and 5% of La) are synthesized by encapsulation of sodium alginate biopolymer using microwave irradiation method. The prepared various compositions of La@CuS are examined by structural characterizations, particle size and identifications of elements from XRD, TEM and EDX spectrum. The surface morphological studies are conformed by SEM and TEM images. Optical properties and characteristics peak are confirmed with UV, FTIR and Raman spectroscopic tools. In addition to that the electrochemical performances are studied using Cyclic Voltammetry (CV), Galvanostatic charge and discharge (GCD) and electrochemical impedance spectroscopy (EIS) investigations. The specific capacitance is found to be 1329 F/g for 5% of La doped CuS nano spheres. • Biopolymer encapsulated CuS and La doped CuS NPs synthesized by chemical reflux method. • La doped CuS NPs were analysed by XRD, FTIR, SEM, TEM and EDX techniques. • La doped CuS NPs were investigated electrochemical studies (CV, GCD and ESI) with 1 M of KOH aqueous electrolyte solution. • Cyclic life of 91% retention of capacitance after 1000 cycles was found. [ABSTRACT FROM AUTHOR]

In this work, we investigate collagen protein powder (CPP) extracted from chromium leather scrap waste (CLSW). The composition and molecular weight distribution of CPP were determined by elemental analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), respectively. The microstructure and size distribution of CPP were then characterized by scanning electron microscopy (SEM) and nanometer analyzer instrument. Finally, CPP was treated with corn starch (CS), and the swelling behavior of the resulting CPP-CS blend was investigated in order to determine its range of applications. The experimental data showed that CPP contains 13 different amino-acids. CPP also displayed low mineral salt levels and a nitrogen content of 43.84%, indicating its potential use as an organic fertilizer. The molecular weight range of CPP is 6.5 to ~ 26.6 kDa. After the obtained CPP was blended with CS, the CPP-CS blend is endowed with optimal swelling properties and is able to overcome the solubility drawbacks of CPP alone. In addition, when the CPP was used as a natural fertilizer, the germination rate and height of kidney beans obviously increased. [ABSTRACT FROM AUTHOR]

Chitosan is a bio-degradable, bio-compatible, non-toxic, and renewable biopolymer. The reactive amino group of chitosan has gained importance because using these amino groups can help achieve the different types of structural modification in chitosan. Chemical modification of chitosan via imine functionalization results in the formation of a chitosan Schiff base. The present review covers the green synthesis of chitosan Schiff bases using non-conventional green methods such as microwave irradiation, green solvent, ultrasound irradiation, and one-pot synthesis. These methods are energy-efficient and greener versions of the conventional condensation methods. Scientists have paid significant attention to the chitosan Schiff base because of its unique properties and versatility. These molecules display various biological applications, including antioxidant, antimicrobial, anticancer, antibacterial, and anti-fungal. In addition to biological applications, chitosan Schiff base also has other applications like corrosion inhibition, catalysis, metal ion adsorption, and as a sensor. Available literature particularly shows the different methods for the synthesis of chitosan Schiff bases and their different applications. This review gives detailed insight regarding sustainable approaches to the synthesis of chitosan derived Schiff bases and their applications in various emerging fields. [Display omitted] • Different methodologies for the green synthesis of chitosan – derived Schiff bases are reported in detail. • Comparative analysis of various green approaches adopted for the synthesis of chitosan-derived Schiff bases. • Applications of chitosan-derived Schiff bases in various fields are discussed. [ABSTRACT FROM AUTHOR]

• PHBV (poly-3-hydroxybutyrate-co-3-hydroxyvalerate), has a potential to replace crude-oil based polymer as a bitumen modifier. • PHBV thermal (softening) properties are compatible to the asphalt mix preparation temperate 160oC. • PHBV shows similar physical properties as the bitumen, ie. soft and sticky to the touch when hot/warm and hard when cold. • HV monomer content in PHBV compound regulates its stiffness, low HV content = high stiffness, high HV content = low stiffness. Bitumen is a key constitutive material in asphalt pavements. It binds together the rock scaffolding of a pavement. Bitumen provides asphalt pavement with flexibility and enables it to respond to traffic loading and return to its original condition after the loading, i.e. bitumen restores/repairs the damage. In Porous Asphalt (PA) or Stonemastic Asphalt Mix (SMA) asphalt mixtures, due its open graded structure, bitumen modifiers are used to improve or restore bitumen physical and mechanical performance. Traditionally bitumen modifiers are made with products of crude oil, such as: ethylene vinyl acetate (EVA) copolymers and styrene–butadiene–styrene (SBS). As crude oil production declines and the environmental and financial costs of crude oil extraction increase, there is a need to identify environmentally sustainable alternatives to use in bitumen. Bitumen modifiers generated from biological sources offer an environmentally friendly and economically viable alternative to crude oil based bitumen modifiers. This paper describes how PHBV (poly-3-hydroxybutyrate-co-3-hydroxyvalerate), a bio-based co-polymer, might be used as an alternative bitumen modifier. The effect of PHBV on 70/100pen was investigated for this paper. The chemical and physical effect of the PHBV on the bitumen performance was investigated using Gel Permeation Chromatography, Fourier Transformed Infrared Spectroscopy, Differential Scanning Calorimetry, microscopic imaging and Dynamic Shear Rheometer tests. The results indicate that PHBV has significant potential as a bitumen bio-polymer modifier. [ABSTRACT FROM AUTHOR]

Biodegradable plastics, mainly represented by polyhydroxyalkanoates (PHAs), could be a good substitute for traditional plastics because of its high biocompatibility and mechanical properties comparable to petroleum-derived plastics. However, the high-cost of raw materials and strict sterilization conditions limit the large-scale application of PHAs. Finding low cost and renewable carbon sources and strains with low environmental requirements are critical to minimize the PHAs production cost. This review provides a comprehensive overview of current research on PHAs production using various organic waste streams. The latest information on PHAs synthesis by pure microbial fermentation and the mixed microbial cultures fermentation technology with activated sludge as the mainstream trend was discussed. Additionally, the review addresses useful information about fermentation strategies and the factors influencing strain enrichment and PHA accumulation. Optimizing the microbial enrichment process through aerobic dynamic feeding is critical for large-scale production of PHAs. Lastly, the challenges, technical bottlenecks, and future perspectives for PHAs industrial production are also discussed. [Display omitted] [ABSTRACT FROM AUTHOR]

To increase the safety of our environments, the selection of proper building block for bio-polymer synthesis becomes vital. This research focused on determining the degree of unsaturation and reactivity of unsaturated milk bush (Thevetia peruviana) oil (TPO). The oil was extracted from Thevetia peruviana seed by Soxhlet extraction method and was further purified. Structural elucidation and characterization of purified TPO was carried out using Proton NMR spectrophotometer, Fourier transform infrared (FTIR) spectrophotometer and Gas chromatography mass spectrometer. The results revealed that the non-edible oil has a triglyceride structure, with 3.16 carbon - carbon double bonds per triglyceride which can be used as starting material to synthesized bio-polymer. [ABSTRACT FROM AUTHOR]