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The purpose of this investigation is to study the influence of Spruce sawdust (SD) coated by magnesium oxide (MgO) nanoparticles in the removing of methylene blue (MB) from an aqueous solution which is in a batch system. The adsorbent was characterized by FTIR, FE-SEM, BET and XRD analysis. The high adsorption potential of SD-MgO nano-biocomposite was revealed by these findings, therefore, it is usable for dye-containing wastewater treatment. By investigating the impact of particular conditions like MB concentrations, the dose of adsorbent and pH, it became possible to confirm the effectiveness of the process. The OOP (which stands for Optimum Operating Parameters) were evaluated by RSM (which stands for Response Surface Methodology) which is based on BBD (Box-Behnken design) and is used for removing MB dye. The adsorbent dosage is the highest effective degree of the individual factor on MB removal. Maximum removal of MB dye was detected at pH 11 with 3.50 g L-1 adsorbent dosage. The surface area of 0.873 m2 g-1 and mesoporous adsorbent prepared gave good adsorption capacity of 26.657 mg g-1 for MB. Furthermore, in order to predict the empirical variables’ significance, the variances’ analysis (ANOVA) was used. The predicated removal efficiency which is proved to be the potency of the process and its effectiveness was found to be 94.05%. Different equilibrium and kinetic models were utilized to the experimental data. Both Pseudo-second order kinetic model and Freundlich adsorption isotherm showed the better fitness to the experimental data.

In recent years, controlled drug delivery has become an important area of research. Nano-biocomposites can fulfil the necessary requirements of a targeted drug delivery device. This review describes use of polymeric nano-biocomposites in controlled drug delivery devices. Selection of suitable biopolymer and methods of preparation are discussed. [ABSTRACT FROM AUTHOR]

The essence of the present research is based on reinforcement mechanism of hibiscus cannabinus fiber (KF) and graphene nanoplatelets (GNP) on mechanical and thermal properties of hybrid hibiscus cannabinus fiber/polypropylene (PKMG 1–5 phr) nano-biocomposites. TGA results revealed inclusion of KF and GNP enhanced charring and thermal stability of the bio-nanocomposites. DSC analysis revealed improved melting and crystallization temperatures of the materials. Flexural modulus significantly increased on inclusion of 20 wt.% kenaf fiber and 5 phr GNP. XRD studies confirmed KF and GNP induced nucleation of β-crystals of PP which improved toughness and impact properties of the nano-biocomposites especially at 3 phr.

Water quality is deteriorating continuously as increasing levels of toxic inorganic and organic contaminants mostly discharging into the aquatic environment. Removal of such pollutants from the water system is an emerging research area. During the past few years use of biodegradable and biocompatible natural additives has attracted considerable attention to alleviate pollutants from wastewater. The chitosan and its composites emerged as a promising adsorbents due to their low price, abundance, amino, and hydroxyl groups, as well as their potential to remove various toxins from wastewater. However, a few challenges associated with its practical use include lack of selectivity, low mechanical strength, and solubility in acidic medium. Therefore, several approaches for modification have been explored to improve the physicochemical properties of chitosan for wastewater treatment. Chitosan nanocomposites found effective for the removal of metals, pharmaceuticals, pesticides, microplastics from the wastewaters. Nanoparticle doped with chitosan in the form of nano-biocomposites has recently gained much attention and proven a successful tool for water purification. Hence, applying chitosan-based adsorbents with numerous modifications is a cutting-edge approach to eliminating toxic pollutants from aquatic systems with the global aim of making potable water available worldwide. This review presents an overview of distinct materials and methods for developing novel chitosan-based nanocomposites for wastewater treatment. • Chitosan a bio-sorbent play an important role in wastewater treatment. • Nanocomposites reduce wastewater pollutants with wider applications. • Nanocomposites affect the metal sorption properties during wastewater treatment. • Chitosan showed potential adsorption in the removal of toxic chemicals. [ABSTRACT FROM AUTHOR]

Poly(3hydroxybutyrate- co -4hydroxybutyrate) (P(3HB- co -4HB)) is a polyhydroxyalkanoate (PHA), which is known for its properties and performance leading to a wide range of applications. Compared to more conventional PHAs such as P(3HB) or P(3HB-4HV), P(3HB- co -4HB) is known for its mechanical properties. P(3HB- co -4HB) has the potential to replace some fossil-based thermoplastics in certain fields. However, it is thermally sensitive like most PHAs and this puts limitations on its potential as an important biobased and biodegradable polymer. The present work is based on the study of multiphase systems of P(3HB- co -4HB) elaborated to prepare nano-biocomposites using two nanoclays, montmorillonite (MMT) and sepiolite (Sep). The clays differ in geometries with MMT having sheet structure and Sep having fiber structure. The environment-friendly non-solvent based elaboration of P(3HB- co -4HB) in the presence of nanoclays allows for minimizing thermal degradation while improving the overall mechanical properties and thermal resistance of the final multiphase materials. The degree of improvement in the properties is found to be not only a function of the clay dispersion in the polymer matrix but also on the morphology/shape of the clay particles and interfacial polymer-clay interactions. It has been found that despite the higher aspect ratio of lamellar-type MMT clays, the fiber-like Sep clay has better stiffening properties arising mainly from the better polymer-clay interactions through the silanol groups along the length of the fiber. As a result of this increased “effective” aspect ratio of Sep, the properties of the Sep-based nano-biocomposites are greatly enhanced. The detailed analyses using various techniques (TGA, DSC, TEM, XRD, uniaxial tensile test) allows comparison and analysis of the structure-property relationships between MMT and Sep nano-biocomposites. [ABSTRACT FROM AUTHOR]

Thiol-Michael addition of pentaerythritol tetrakis(3-mercaptopropionate) (PE3MP) to a high oleic sunflower oil derivative containing enone groups (ETG), has been used to prepare vegetable oil derived renewable thermosets in an efficient way and under mild conditions. The same formulation has been used to prepare nano-biocomposites by incorporating into the polymerization mixture, 1 wt%, 5 wt% and 10 wt% of cellulose nanocrystals (CNC) modified with Beycostat A B09® as surfactant. The chosen methodology allows a good dispersion of the nano filler in a low polarity reactive media which still is a challenging approach. The morphological, thermal and mechanical properties of the different nano-biocomposites were evaluated and compared with the pristine thermoset. Morphological analysis shows that good dispersion of the nanofillers is achieved in all formulations. Mechanical properties show an improvement of the Young Modulus for all nanofiller contents, showing a maximum at 5 wt% loading (32 and 78 MPa for the pristine and 5% CNC nano-composite respectively) that has been related with the reinforcement effect of the modified CNC. CNC dispersion also affects positively the surface properties, thus reducing drastically the contact angle values (78.0–16.0° for the pristine and 10% CNC nano-composite respectively). Finally, protein adsorption was measured in order to evaluate potential application of these materials as biosensors and cell growing supports. [ABSTRACT FROM AUTHOR]

The main directions in food packaging research are targeted towards improvements in food quality and food safety. For this purpose, food packaging providing longer product shelf-life, as well as the monitoring of safety and quality based upon international standards, is desirable. New active packaging strategies represent a key area of development in new multifunctional materials where the use of natural additives and/or agricultural wastes is getting increasing interest. The development of new materials, and particularly innovative biopolymer formulations, can help to address these requirements and also with other packaging functions such as: food protection and preservation, marketing and smart communication to consumers. The use of biocomposites for active food packaging is one of the most studied approaches in the last years on materials in contact with food. Applications of these innovative biocomposites could help to provide new food packaging materials with improved mechanical, barrier, antioxidant and antimicrobial properties. From the food industry standpoint, concerns such as the safety and risk associated with these new additives, migration properties and possible human ingestion and regulations need to be considered. The latest innovations in the use of these innovative formulations to obtain biocomposites are reported in this review. Legislative issues related to the use of natural additives and agricultural wastes in food packaging systems are also discussed.

Chitin nano-size fillers, i.e. nanocrystals (CHNC) and nanofibers (CHNF), were incorporated in thermoplastic starch matrix via melt-mixing. The two types of thermoplastic starch-based nano-biocomposites (S/CHNC and S/CHNF) were characterized and compared in terms of morphology, chemical and crystal structure, thermal and mechanical properties, and water resistance. In general, all thermoplastic starch-based nano-biocomposites showed better thermal stability, mechanical properties, and storage modulus than thermoplastic starch matrix without chitin nano-size fillers. This can be linked to the good dispersion of the nano-size fillers in the matrix, resulting from their chemical similarity, and also to the strong nano-size fillers-matrix adhesion by hydrogen bonding interactions. The results showed that the final properties of the nano-biocomposites were dependent of the concentration and type of chitin nano-size filler introduced in the thermoplastic starch matrix. In general, the thermoplastic starch-based nano-biocomposites prepared with chitin nanofibers showed better thermal and mechanical properties and storage modulus than those prepared with chitin nanocrystals. [ABSTRACT FROM AUTHOR]

Population growth and industrialization is associated with the elevation of hazardous pollutants, including heavy metals, biomedical wastes, personal-care products, endocrine-disrupters, pharmaceutically active compounds, and colorants in the environment. The scientific focus has been devoted to developing novel adsorbents to mitigate hazardous pollutants by constructing hybrids of different polymers and nano-structured materials for improved workability and physicochemical attributes. Recently, much attention has been devoted to nanomaterials in environmental remediation, owning to their exceptional characteristics including novel electrical/chemical features, quantum size effects, tunable functionalization, high scalability, and surface-area-to-volume ratio. Target-specific designing of nanocomposites impart high functionality. The cost-effective and eco-friendly synthesis of bioadsorbent materials is increasing for the removal of hazardous pollutants. Due to biocompatible, biodegradable, and eco-friendly nature, sodium alginate has been widely reported for the preparation of bioadsorbent materials to remove different inorganic/organic pollutants. In this review, the potentialities of alginate-based nanocomposites have been described for environmental remediation purposes. Different nanomaterials, including silica, metallic oxide, graphene oxide, hybrid inorganic-organic, non-magnetic-magnetic, carbon nanorods, nanotubes, polymeric nanocarriers, and several other materials have been described in combination with alginate biopolymer for environmental remediation. [Display omitted] • Alginate-based nano-adsorbent materials to remediate pollutants are reviewed. • Recalcitrant pollutants present a serious threat to environmental sustainability. • Various nanohybrids-assisted remediation approaches are given for pollutants. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this work was to predict the effective elastic properties of starch-based nano-biocomposites. Experiments (materials elaboration, morphological characterization and determination of mechanical properties) were conducted on both the pristine matrix (plasticized starch) and the matrix filled with montmorillonite nanoclay. Aggregated/intercalated and exfoliated nano-biocomposites were produced and mechanically tested under uniaxial tension to understand the effect of montmorillonite morphology/dispersion on the stiffness properties of starch-based nano-biocomposites. Micromechanical models, based on the classical bounds and the Mori–Tanaka approaches, were developed taking into consideration the influence of the clay concentration, the exfoliation ratio, the relative humidity and the storage time (ageing). Predicted results are in a good agreement with our experiments and show that the micromechanical model can be used as an indirect characterization technique to quantify the exfoliation/aggregation degree in the plasticized starch/clay nano-biocomposites. [Copyright &y& Elsevier]

In this article, the effect of the addition of halloysite nanotube (HNT) on the mechanical and thermal stability of polypropylene (PP) and PP/kenaf fiber biocomposites has been investigated. Different volume contents of HNTs ranging from 1 to 10 vol.% were melt mixed with PP and PP/kenaf fibers. The volume content of kenaf fibers was kept constant at 30%. The morphology of HNTs within the PP matrix has been studied via scanning electron microscopy (SEM). The morphological results revealed that HNT was uniformly dispersed in the PP matrix already at a low concentration of 1 and 2 vol.%. The mechanical properties of the manufactured nanocomposites and hybrid biocomposites such as Young's modulus, tensile strength, elongation at break, flexural modulus, flexural strength, and notched Izod strength have been measured. The results show that Young's modulus and strengths have been improved along with the addition of low content of HNTs. Moreover, the gain of notched Izod impact strength obtained by the addition of short kenaf fibers was maintained in hybrids with low concentrations of HNTs. Finally, the thermogravimetric analysis shows that at 10% and 50% weight loss, the thermal degradation rate of the PP and PP/kenaf biocomposites decreased by the addition of HNTs. [ABSTRACT FROM AUTHOR]

The main directions in food packaging research are targeted toward improvements in food quality and food safety. For this purpose, food packaging providing longer product shelf-life, as well as the monitoring of safety and quality based upon international standards, is desirable. New active packaging strategies represent a key area of development in new multifunctional materials where the use of natural additives and/or agricultural wastes is getting increasing interest. The development of new materials, and particularly innovative biopolymer formulations, can help to address these requirements and also with other packaging functions such as: food protection and preservation, marketing and smart communication to consumers. The use of biocomposites for active food packaging is one of the most studied approaches in the last years on materials in contact with food. Applications of these innovative biocomposites could help to provide new food packaging materials with improved mechanical, barrier, antioxidant, and antimicrobial properties. From the food industry standpoint, concerns such as the safety and risk associated with these new additives, migration properties and possible human ingestion and regulations need to be considered. The latest innovations in the use of these innovative formulations to obtain biocomposites are reported in this review. Legislative issues related to the use of natural additives and agricultural wastes in food packaging systems are also discussed.