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Engineered living materials (ELMs) are a fast-growing area of research that combine approaches in synthetic biology and material science. Here, we engineer B. subtilis to become a living component of a silica material composed of self-assembling protein scaffolds for functionalization and cross-linking of cells. B. subtilis is engineered to display SpyTags on polar flagella for cell attachment to SpyCatcher modified secreted scaffolds. We engineer endospore limited B. subtilis cells to become a structural component of the material with spores for long-term storage of genetic programming. Silica biomineralization peptides are screened and scaffolds designed for silica polymerization to fabricate biocomposite materials with enhanced mechanical properties. We show that the resulting ELM can be regenerated from a piece of cell containing silica material and that new functions can be incorporated by co-cultivation of engineered B. subtilis strains. We believe that this work will serve as a framework for the future design of resilient ELMs., Despite the advances in engineered living materials (ELMs), the diversity of ELMs especially those that are capable of autonomous self-fabrication and regeneration, is low. Here, the authors engineer a resilient ELM biocomposite using Bacillus subtilis and secreted EutM proteins as selfassembling scaffold building blocks.

Biocomposites have been implemented in various industrial applications. However, it is necessary to demonstrate their desired mechanical performance aspects for the near future green products. The aim of this work is to study the efficiency of utilizing both coconut and pomegranate lignocellulosic fiber as green reinforcement types for the low-density polyethylene, LDPE. Desired mechanical performance trends are investigated for the green composites including the tensile strength, tensile modulus, and elongation to break properties as a function of various reinforcement configurations. This was performed to properly optimize the reinforcement conditions to obtain desirable mechanical characteristics of such types of bio-composites for more sustainable functional attributes. Results have demonstrated that the best tensile strength for the coconut/PE was achieved at 20wt.% case with 8.2 MPa, and the best regarding this property for the pomegranate/PE was at 30wt.% with a value close to 8.3 MPa. Moreover, obvious inverse relationship between strength and strain for the coconut composite type was revealed at both low and high fiber contents. It was also noticed that the 20wt.% coconut-based composite has demonstrated the best optimal values of tensile strength and tensile modulus simultaneously. But no reinforcement condition was found for pomegranate/LDPE as an optimal for these mechanical properties concurrently.

As increasing environmental awareness drives the development of biocomposites, the reality is that these material are still far behind in terms of application. While modifications on biocomposites do improve its properties, they are often conducted individually per study and not altogether, which may limit its potential. To expand the marketability of biocomposites, this research covers the hybridization of natural and synthetic fibre, reinforcement of Sodium Hydroxide (NaOH) treated kenaf fibre, reinforcement of organomodified nanoclay, and the use of modified epoxy in the production of the biocomposite. The dispersion of nanoclay in modified epoxy was conducted via sonication while the selected composite fabrication method is hand lay-up. In the flexural test, treated kenaf composites increase by 52% in flexural strength and 46% in flexural modulus, while treated nanocomposites improve by 83% in impact absorbed energy. The rough surface of treated kenaf and fractured composite surface can be seen using a Field Emission Scanning Electron Microscope (FESEM), indicating high interfacial adhesion in treated kenaf composites. Spectroscopy investigation utilising Fourier Transform Infrared (FTIR) revealed that hemicellulose is easier to be removed with alkalization compared to lignin. X-Ray Diffraction Analysis (XRD) displays higher crystallinity in nanocomposites due to nanoclay.

Aiming to adds value to agricultural products and develop environmental-friendly and cost-effective materials, the present work investigates the influence of babassu mesocarp (BM) flour extractives and the addition of maleic anhydride-modified polyethylene (MAPE), as a coupling agent, on the properties of additivated polyhydroxybutyrate (PHBad)/BM biocomposites. The extractives were partially and completely removed from BM flour by detergent and soxhlet extraction, respectively, before biocomposites melt processing. The thermal, mechanical, structural, morphological, and flow properties of biocomposites with extracted BM flours were determined and compared to the properties of biocomposite with BM flour in natura. In addition, the influences of MAPE incorporation in the properties of each biocomposite were also studied, in order to understand their role in biocomposite compatibilization. The particle treatments resulted in biocomposites with lower tensile strength than biocomposites with BM in natura. Despite the low compatibility of MAPE with PHB, the addition of MAPE increased the tensile strength of the respective PHB biocomposite, reaching values of tensile strength similar or slightly higher than the PHBad-MAPE matrix. Therefore, MAPE acted as an effective additive for BM flour, probably, due to reactive processing with the starch polar surface groups. Since BM was abundantly and cheaply available, its use with PHB and MAPE resulted in biodegradable material with similar mechanical properties of neat PHB and concomitant reduction in cost.

The current work mainly focuses on the innovative nature of nano-gallium-substituted hydroxyapatite (nGa-HAp)/Pergularia daemia fiber extract (PDFE)/poly(N-vinylcarbazole) (PVK) biocomposite coating on titanium (Ti) metal in an eco-friendly and low-cost way through electrophoretic deposition for metallic implant applications. Detailed analysis of this nGa-HAp/PDFE/PVK biocomposite coating revealed many encouraging functional properties like structure and uniformity of the coating. Furthermore, gallium and fruit extract of PDFE-incorporated biocomposite enhance the in vitro antimicrobial, cell viability, and bioactivity studies. In addition, the mechanical and anticorrosion tests of the biocomposite material proved improved adhesion, hardness, and corrosion resistance properties, which were found to be attributed to the presence of PDFE and PVK. Also, the swelling and degradation behaviors of the as-developed material were evaluated in simulated body fluids (SBF) solution. The results revealed that the as-developed composite exhibited superior swelling and lower degradation properties, which evidences the stability of composite in the SBF solution. Overall, the results of the present study indicate that these nGa-HAp/PDFE/PVK biocomposite materials with improved mechanical, corrosion resistance, antibacterial, cell viability, and bioactivity properties appear as promising materials for biomedical applications.

We developed a novel BW-CS/ZnHA biocomposite utilizing Beeswax-Chitosan and Zinc-hydroxyapatite nanoparticles (ZnHAP). The uniformed mixture of beeswax-chitosan and ZnHAP was freeze-dried to get a porous biocomposite. The fabricated biocomposite was characterized using FTIR, XRD, and SEM. Moreover, the antibacterial, swelling, biodegradations, viability, and cell proliferation capacity of the fabricated biocomposite was assessed. The biocomposite demonstrated upgraded swelling and antibacterial activity. The addition of ZnHAP accomplished the antibacterial activity. Biocompatibility studies were carried out using osteoblast cells and thus we proved the non-toxic nature of the biocomposite. Osteoblast cell adhesion investigations demonstrated that the cells were appended and infiltrated into the inside of the biocomposite. The obtained results encourage the use of these bandages for various types of wounds with infection and exudates.

Golden glittering biocomposite fibers from poly(lactic acid) (PLA) and nanosilver-coated titanium dioxide (Ag/TiO2) were successfully prepared via a melt spinning process. Various contents of 10% Ag/TiO2/PLA masterbatch were diluted with PLA in concentrations of 5, 10, 15, 20, 25, and 30 phr, respectively. The physical, mechanical, thermal, and antibacterial properties of the obtained fibers were investigated. The results indicated that the glittering biocomposite fiber had a light, yellow-gold color and a slightly rough surface. Tenacity and elongation at break of the glittering biocomposite fibers were lower than those of the pristine PLA fiber. The thermal properties of the glittering composite fibers also decreased with increasing masterbatch content. The PLA/PEG-10 biocomposite fiber with good spinnability and mechanical properties was suitably used for preparing the golden glittering composite fabric by the knitting process. Moreover, the golden glittering biocomposite fabrics exhibited antibacterial activity against certain microbes, for example, Staphylococcus aureus, Bacillus subtilis, and Candida albicans. The prepared fabric has significant potential for use in eco-friendly textile products and antibacterial fabrics. Besides, our novel textiles showed not only the photocatalytic property needed to degrade organic dyes such as methylene blue in water but also the ion-sensing property for mercury(II) ions by changing the textile color from yellow to colorless.

Green reinforcement in biopolymer for enhanced industrial application is on the increase. Bio-precipitated CaCO3 was synthesised via the process of microbially-induced calcium carbonate precipitation using Bacillus sp. strain. The bio-precipitated CaCO3 (B-PCC) and conventional CaCO3 precipitates (C-PCC) reinforcement effect on the properties of Eucheuma cottonii film was analysed and compared. The biocomposite films were fabricated using a solvent casting technique. The physicomechanical, thermal and biodegradability performances of B-PCC and C-PCC incorporated E. cottonii film with increasing fillers' contents [0.05, 0.10, 0.50, 1.00, 2.00 (wt.%)] were determined and compared through a range of testing include water vapour permeability (WVP), contact angle using sessile drop method, scanning electron microscopy (SEM), tensile, elongation, Young's modulus, thermogravimetric analysis (TGA), and soil burial test. A further comparison was made between the E. cottonii biocomposite film with the existing biodegradable mulch films to evaluate its potential application using wet cup method. Results revealed that biocomposite films embedded with 0.1% B-PCC appeared to exhibit higher water barriers and hydrophobicity behaviours than those embedded with C-PCC. However, the mechanical strength and thermal stability were slightly lower than those embedded with C-PCC. E. cottonii biocomposite films, especially those embedded with 0.1 wt. % B-PCC has shown the potential in agricultural mulch film as it promoted better biodegradation and tensile strength by 34.24% and 20% respectively compared to the existing biodegradable PLA/PBAT mulch film, making it a promising alternative to the conventional plastic to mitigate plastic pollution.

The demand of antimicrobial active packaging is escalating due to the needs of improving quality and shelf life of food. In this work, sugar palm starch (SPS)/sugar palm nanocrystalline cellulose (SPNCC) incorporated with cinnamon essential oil (EO) biodegradable nanocomposite films were prepared by using solvent casting method. Mechanical properties test revealed that films incorporated with cinnamon EO showed improved tensile strength and tensile modulus values from 4.8 to 5.3 MPa and 122.49–130.52 MPa respectively. Additionally, the density and moisture content were reduced from 1.38 to 1.31 g/cm3 and from 13.65 to 12.33% respectively. The antimicrobial test was carried out by agar disc method (ADM) to evaluate the inhibition effect of the films on the gram positive bacteria, gram negative bacteria and yeast. The result suggested that The higher the amount of EO used (2.0 wt) yielded, the higher the inhibition zone occurred for B. subtilis, S. aereus and E. coli, which were 7.85, 6.63, and 7.43 mm respectively. Overall, cinnamon EO incorporated SPS/SPNCC biodegradable nanocomposite film is a good candidate as an alternative for active packaging material.

In this study, a poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) modified with nano-montmorillonite biocomposite (MMT/PHBH) was fabricated by solution-casting method. The results showed that the addition of MMT increased the crystallinity and the number of spherulites, which indicated that MMT was an effective nucleating agent for PHBH. The maximum decomposition peak of the biocomposites moved to a high temperature and residue presented an increasing trend. The biocomposites showed the best thermal stability at 1 wt% MMT. Compared with PHBH, 182.5% and 111.2% improvement in elastic modulus and tensile strength were obtained, respectively. Moreover, the oxygen permeability coefficient and the water vapor permeability of MMT/PHBH biocomposites decreased by 43.9% and 6.9%, respectively. It was also found that the simultaneous enhancements on the crystallizing, thermal stability, mechanical, and barrier properties of biocomposites were mainly caused by the formation of intercalated structure between PHBH and MMT.

Dried and well-consolidated sheet of bacterial cellulose (BC) nanofibrils is a material structure that possesses high modulus and strength but is also brittle, which limits its potential in various advanced composite applications. Here, we report a simple method of enhancing the toughness of BC sheet by sizing the BC nanofibrils with poly(ethylene glycol) (PEG). This hinders interfibril hornification and facilitates large-scale BC nanofibril debonding, slippage and reorientation upon deformation. The PEG-sized BC sheets show high tensile strain-at-failure and work of fracture compared to neat BC sheet. PEG-sized BC reinforced laminated acrylic composites achieve a flatwise Charpy impact strength of up to 26 kJ m−2. This is a remarkable increase over the impact strength of neat impact-modified acrylic of only 12 kJ m−2, especially when the BC loading required to achieve this radical improvement is only 0.2 wt-%. Our study opens new paradigm in using low BC loading to achieve performance improvements suitable for high value composite applications.

The mycelium composites composed of fungal mycelium and plant substrate are a practical alternative to petroleum plastic-based foam materials. However, the effects of the physiological traits of fungus on the composites’ microscopic structure and mechanical properties remain poorly understood. Here, we compared two basidiomycetes with distinct mycelium morphology and white-decay modes. Cross-sectional observation revealed that the mycelium composites possess a core/shell structure with the shell formed of dense aerial mycelium and the core of plant particles and spongy aerial mycelium. Dense and continuous mycelium networks provided by Trametes hirsuta strengthen the mechanical properties of the composite compared to the coarse mycelium networks of Pleurotus ostreatus. In particular, the firm mycelial shell skeleton confers high flexibility and shape-retention to the composite in the wet state. This unique characteristic of the mycelium composite indicates its potentials in new industrial applications.

The narrow process temperature window available to consolidate self-reinforced PLA composites is one of the challenges for the application of this type of composites. In the present work, the effect of the consolidation temperature on the polymer crystallinity and the mechanical performance of self-reinforced PLA composites is studied and characterized. On the filament level, the results show that the Young’s modulus of PLA reinforcement filaments increases with exposure to consolidation temperature (12%) and the strength at break decreases (30%). With an additional annealing process, the Young’s modulus of a semi-crystalline PLA matrix may increase, while the properties of the PLA reinforcement filaments remain unaffected. On the composite level, the results show that an increase of the consolidation temperature results in lower strength and higher strain at break. Based on the experimental findings, optimal processing conditions for the selected PLA grades are recommended to produce self-reinforced PLA composites.

In pursuit of new biobased materials for a sustainable world, glasswort (Salicornia europaea) was utilized in this study as a natural fiber to develop a biocomposite material. Glasswort (GW) reinforced high-density polyethylene (HDPE) composites at different GW percentages were prepared with a high-speed thermo-kinetic mixer. The effect of GW on HDPE composites was thoroughly investigated with Fourier transform infrared (FTIR) spectroscopy, tensile and flexural tests, dynamic mechanical analysis, water contact angle measurements, and scanning electron microscopy (SEM). A new method was also developed by seawater immersion of samples to conduct microbiological analysis. The method included bacteria population count with respect to time. Biointegration was reported to increase as 25% for 20 wt% GW-filled HDPE. The tensile modulus of HDPE increased up to 20% with GW inclusion. The unique properties of this novel composite material proved that GW can be a promising natural fiber for polymer composites. © 2021 Taylor & Francis., IKC-ÖNP-MÜM-0002 project supported by Izmir Katip Celebi University Research Funds is greatly acknowledged.

Biocomposites processed with polycaprolactone (PCL) and macaiba fiber (MF) were melting extruded in this work with MF content ranging from 10% to 20%. MF was naturally added to PCL as also chemically treated with maleic anhydride (MA), sodium hydroxide (NaOH), and 3-Methacryloxypropyltrimethoxysilane (Silane). Afterwards biocomposite were thermally, spectroscopically, mechanically and morphologically characterized. From the gathered results, higher thermal stability was observed for biocomposites upon higher MF content, regarding the chemical treatment MA presented the best performance whereas NaOH the lowest, similar trend was also verified with mechanical behavior. From contact angle and water absorption results it was suggested macaiba oil exudation to the surface acts decreasing interaction with water and, therefore, increasing the contact angle, while the added MF provide more opened structure which favors the water entrance, whereas the time and polarity effects should be recognized, which eases H2O entrance from surface to biocomposites core and improve interactions between PCL matrix and MF, respectively being translated in higher compatible biocomposites. Summing up, biocomposites with 10% of natural or treated macaiba fiber presented the best synergism. MF addition to PCL provides a sustainable alternative to PCL biocomposites, besides supplying the literature with new information on applications of natural and chemically treated macaiba fibers.

The conventional approaches for treating bone defects such as autografts donor tissue shortages and allografts transmission of diseases pose many shortcomings. The objective of this study was to design a nano strontium/magnesium doped hydroxyapatite (Sr/Mg-HA) with chitosan (CTS) and multi-walled carbon nanotubes (MWCNT) (Sr/Mg-HA/MWCNT/CTS) biocomposite was created to support the growth of osteoblasts using a solvent evaporation method. To help the growth of osteoblasts, a solvent evaporation technique was used to design a nano strontium/magnesium doped hydroxyapatite with chitosan and multi-walled carbon nanotubes biocomposite. We studied the biocompatibility and efficiency in vitro of biocomposite following physicochemical analyzes. Tests of biocompatibility, cell proliferation, mineralization, and osteogenic differentiation have shown that in-vitro safety and effectiveness of biocomposite are good. The performance of biocomposite was more efficient in in-vitro as well as in vivo experiments than in Sr/Mg-HA nanoparticles. Briefly, the Sr/Mg-HA/MWCNT/CTS biocomposite is an ideal candidate for effective bone repair in clinics with excellent mechanical properties with durable multi-biofunctional antibacterial properties and osteoinductivity.

Skin burn wounds are a crucial issue that could reduce life quality. Although numerous effective skin products have invaded the biomedical market, most of them still demonstrate some limitations regarding their porosity, swelling and degradation behaviors, antibacterial properties, and cytotoxicity. Thus, the aim of this study is to fabricate novel trilayered asymmetric porous scaffolds that can mimic the natural skin layers. In particular, the fabricated scaffold constitutes an upper electrospun chitosan–poly(vinyl alcohol) layer and a lower xerogel layer, which is made of effective skin extracellular matrix components. Both layers are fixed together using fibrin glue as a middle layer. The results of this study revealed promising scaffold swelling capability suitable for absorbing wound exudates, followed by a constant degradable weight over time, which is appropriate for a burn wound environment. Scanning electron microscopy images revealed an average pore diameter in the range of 138.39–170.18 nm for the cross-linked electrospun mats and an average pore size of 2.29–30.62 μm for the fabricated xerogel layers. This further provided an optimum environment for fibroblast migration and proliferation. The electrospun nanofibrous layer was examined for its antibacterial properties and showed expressive complete bacterial inhibition against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacterial strains (log reduction = 3 and 2.70, respectively). Next, mouse embryonic fibroblast cytotoxicity and migration rate were investigated against the developed asymmetrical composite to assess its biocompatibility. Tissue culture experiments demonstrated significant cell proliferation and migration in the presence of the constructed scaffold (P < 0.0001). A complete wound closure was observed in vitro in the presence of the three scaffold asymmetrical layers against the mouse embryonic fibroblast. The results of this study proved superior biological characteristics of the innovative asymmetrical composite that could further replace the burned or damaged skin layers with promising potential for clinical applications.

Background: The purpose was to study the effect of sliding condition on the wear behavior of nanofilled composite material under two-body wear test mechanism. Materials and Methods: In this study, a supreme composite material with nanofiller was subjected to abrasion test procedures' in vitro conditions. In this study, the test samples were divided into two groups and subjected 50 N wear force, 1.6 Hz wear frequency, 240,000 wear cycles, constantly 37°C temperature, and 0.3 mm and 0.6 mm sliding conditions through wear test procedures, respectively. The volume loss in the wear area of the test samples after the wear test procedures was analyzed using a noncontact three-dimensional profilometer. In addition, microstructure analysis was performed by selecting random test samples from each group using scanning electron microscopy. Results: As per the data obtained during this study, with an increase in the amount of lateral movement, the volume loss in the composite material had also increased after wear test procedures. Conclusion: However, the increase in volume loss in the wear area of the composite material did not show a linear relationship with the amount of lateral movement.

Natural biomaterials are potential candidates for the next generation of green electronics due to their biocompatibility and biodegradability. On the other hand, the application of biocomposite systems in information storage, photoelectrochemical sensing, and biomedicine has further promoted the progress of environmentally benign bioelectronics. Here, we mainly review recent progress in the development of biocomposites in data storage, focusing on the application of biocomposites in resistive random-access memory (RRAM) and field effect transistors (FET) with their device structure, working mechanism, flexibility, transient characteristics. Specifically, we discuss the application of biocomposite-based non-volatile memories for simulating biological synapse. Finally, the application prospect and development potential of biocomposites are presented., Graphical abstract

Polymers such as polycaprolactone (PCL) possess biodegradability, biocompatibility and affinity with other organic media that makes them suitable for biomedical applications. In this work, a novel biocomposite coating was synthesised by mixing PCL with layers of calcium phosphate (hydroxyapatite, brushite and monetite) from a biomineral called otolith extracted from Teleost fish (Plagioscion Squamosissimus) and multiwalled carbon nanotubes in different concentrations (0.5, 1.0 and 1.5 g/L). The biocomposite coating was deposited on an osteosynthesis material Ti6Al4V by spin coating and various tests such as Fourier transformation infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), scratch tests, MTT reduction cytotoxicity, HOS cell bioactivity (human osteosarcoma) by alkaline phosphatase (ALP) and fluorescence microscopy were performed to comprehensively evaluate the newly developed biocoating. It was found that an increase in the concentration of carbon nanotube induced microstructural phase changes of calcium phosphate (CP) leading to the formation of brushite, monetite and hydroxyapatite. While we discovered that an increase in the concentration of carbon nanotube generally improves the adhesion of the coating with the substrate, a certain threshold exists such that the best deposition surfaces were obtained as PCL/CP/CNT 0.0 g/L and PCL/CP/CNT 0.5 g/L.

Mineral substituted hydroxyapatite (MHAp) is one of the most significant bony mineral parts that have been broadly utilized as bony substitution matters as a result of its cytocompatible and bioactive properties. Though, the utilization of hydroxyapatite as bony inserts is confined because of its poor mechanical and fragile properties. To conquer this deformity and to produce appropriate bony embed substance; hydroxyapatite is joined with biocompatible macromoles (kappa-Carrageenan (KCG) and chitosan (CTS)). To improve the mechanical strength of the hydroxyapatite based biocomposite, functionalized multiwalled carbon nanotubes (FMWCNT) is joined to the biocomposite, which has for quite some time been considered for hard and delicate tissue implant because of its remarkable auxiliary and mechanical characteristic properties. It is outstanding that FMWCNT platform is the most-conspicuous substance for the hard tissues reproduction. We have developed a novel FMWCNT/KCG@MHAp nanocomposite on titanium (Ti) implant. The developed nanocomposite coatings implants were portrayed by different strategies (SEM, XRD, TEM). The outcomes show the arrangement and homogeneous conveyance of constituents in the nanocomposite coatings. Addition of FMWCNT and KCG into the MHAp nanocomposite altogether improves the attachment quality and flexible modulus of the scaffolds. Moreover, the reactions of mesenchymal stem cells (MSCs) culture onto the nanocomposite coating show that the suitability of cells was significantly high for FMWCNT and KCG consolidated MHAp than for MHAp. Animal model examinations demonstrate the nearness of delicate osteoblast and fibrous tissue development with no noteworthy provocative symptoms, which recommends that the Addition of FMWCNT and KCG encourage the great biochemical role of MHAp. For load-bearing applications, examine in different bony models is expected to substantiate the medical accessibility. In this manner, from the acquired outcomes, we propose that FMWCNT/KCG@MHAp nanocomposite can be considered as a prospective possibility for orthopedic applications. Keywords: Carrageenan, Chitosan, Carbon nanaotubes, Hydroxyapatite, Nanocomposite, Titanium

This study was conducted to fabricate scaffold from polylactic acid (PLA) and hydroxyapatite (HA) extracted from waste bovine bone for enhancing both mechanical and biocompatible properties. After pretreatment in dilute NaOH solution, the bone was calcined at 900°C for 6 h, ball milled and converted to HA. Factors that affect the formation of HA were investigated. Experimental results showed that HA particles with crystal size < 100 nm and 99% crystallinity could be obtained at 90°C, pH 11 and 35 mM H3PO4 solution followed by 4 h calcination at 900°C. By using non-solvent induced phase separation method, PLA scaffolds with pore size and surface area of 22.6 μm and 25.7 m2/g, respectively, containing different hydroxyapatite were successfully prepared. Tensile strength of scaffolds increased due to effective support by HA grafted collagen. PLA scaffolds containing HA were more degradable than PLA scaffolds and PLA scaffolds containing HA grafted collagen. Cell culture results showed that cell density increased significantly on porous scaffolds than that on the dense scaffolds. Moreover, cell density also increased significantly on the scaffold containing HA grafted collagen than that on the scaffold with pure HA.

In Indonesia, starch, particularly that obtained from bengkuang (Pachyrhizus erosus), is abundant and inexpensive, thereby increasing the value of bengkuang starch, which can be mixed with bioplastic-based starch. A biocomposite comprising nanocellulose from water hyacinth (Eichhornia crassipes) and bengkuang starch was successfully fabricated using the solution casting method. Nanocellulose content in the matrix was kept constant at 1 wt%. Moreover, during fabrication, the biocomposite gel was treated in an ultrasonic bath for 0, 15, 30, and 60 min. Further, thermogravimetric analysis, moisture absorption measurements, Fourier transform infrared spectroscopy, and scanning electron microscopy were performed. The biocomposite sample vibrated for 60 min had the highest thermal stability and exhibited low moisture absorption. The soil burial test proved that this biocomposite, as opposed to 0-min vibrated samples, has a slower biodegradation rate. This result was supported by morphological evaluation after biodegradation, in which the 60-min vibrated samples showed a coarse surface and low porosity formation. Keywords: Nanocellulose, Biodegradation, Biocomposites, Hyacinth fiber, Thermogravimetric analysis

Nano adsorbent possess notable adsorption capabilities but is difficult to recover in wastewater treatment processes. To overcome this limitation, the entrapment of nanocellulose (NCC) and chitosan (Cts) within poly(hydroxyalkanoate) (PHA) via electrospinning is proposed. The Pickering emulsion stabilized with Tween 80 formed a homogeneous NCC-Cts-PHA mixture prior to electrospinning. The resulting electrospun biocomposites were characterized with SEM, FT-IR, XrD and TGA. The electrospun biocomposites were with high porosity, rendering exposure of NCC and Cts to dye adsorption. The incorporation of nanocellulose and chitosan significantly increased the crystallinity of the electrospun biocomposites from 57.6% to 70.5%. The adsorption of Congo red dye by electrospun biocomposites fitted well with the Langmuir isotherm model and pseudo-second order kinetics, indicating a chemisorption nature. PHA2NCC (30.9%) has 3-fold higher dye removal percentage than that of PHA2Cts (10.5%). The results showed that Pickering emulsion is electrospinnable and recorded highest dye removal percentage in PHA3NCC1Cts (75.8%). Keywords: Nanocellulose, Chitosan, Electrospinning, Pickering emulsion, PHA, Wastewater

In response to the pervasive anthropogenic pollution of the ocean, this manuscript suggests the use of biodegradable elastomers in marine applications. The present study characterizes 25 samples of highly biodegradable polymers, obtained blending a base elastomer with natural fibers. Mechanical analysis and Scanning Electron Microscope imaging, reveal how base polymers behave differently depending on the plant fiber chosen, on the external forcing—exposure to water—and on the doses that constitute the final biocomposite. Results suggest that EcoflexTM 00-30 and EcoflexTM 00-50, mixed with potato starch, perform best mechanically, maintaining up to 70% of their maximum tensile strain. Moreover, early signs of degradation are visible on polysiloxane rubber blended with 50% vegetable fibers after 19 hours in distilled water. Analyses demonstrate that highly biodegradable elastomers are good candidates to satisfy the requirements of aquatic devices. Furthermore, the discussed materials can improve the dexterity and biodegradability of marine technology.

Synthetic fibre reinforcements are increasingly replaced with plant fibres but an improvement in the mechanical performance of biocomposites is required. Flax composite exhibits fibre failure and perforation even at low impact energies. This paper investigates the viability of improving the impact resistance of flax-epoxy biocomposite by hybridisation with a thin metal layer. High-speed cameras and optical microscopy were used to measure the dissipated energy and to identify the different damage modes. The impact response of hybrid biocomposites was compared to a reference GFRP composite and monolithic biocomposites and it was shown that the deformation and damage is significantly reduced in the hybrid configuration. Additionally, a numerical model was developed in Abaqus/Explicit and validated in terms of the displacement history and damage modes. The study reveals the effect of various material configurations and thicknesses on impact damage resistance and proves that the penetration resistance of biocomposites is improved by hybrid construction. publishedVersion

This work aimed to prepare ulluco starch (US)/chitosan (Ch) edible films and evaluate the effect of the concentration of US on their physicochemical properties. The use of edible films is a means of adding value to the ulluco crop and evaluating the viability of using new sources to produce packaging materials. Different samples were prepared at different US concentrations (2%, 3%, 4%, and 5% w/v) and a fixed chitosan concentration (1.5% w/v); then, samples were analyzed, considering their physical, mechanical, and thermal properties. The US/Ch edible films showed an increase in solubility from 17.5% to 21.7%, swelling power (SP) from 38.9% to 267%, tensile strength (TS) from 3.69 MPa to 10.7 MPa, Young modulus (YM) from 18.0 Pa to 652 Pa, and thermal stability as the US concentration increased. However, samples with low US concentrations showed higher elongation at break (EB) (36.6%) and better barrier properties (WVP) (5.61 × 10−11 g/m s Pa). The films evaluated in this work presented good physical, mechanical, and barrier properties, revealing their potential as packaging material ensuring food security, and demonstrating the technological potential of US.

The aim of this study was to evaluate the moisture absorption behaviour and its influence on the mechanical properties of newly developed sandwich biocomposites with flax fibre-reinforced poly-lactic acid (PLA) face sheets and soft cork as the core material. Three different types of sandwich biocomposite laminates comprised of different layup configurations, namely, non-woven flax/PLA (Sample A), non-woven flax/PLA and cork as core (Sample B) and non-woven flax/paper backing/PLA, cork as core (Sample C), were fabricated. In order to evaluate the influence of moisture ingress on the mechanical properties, the biocomposites were immersed in seawater for a period of 1200 h. The biocomposites (both dry and water immersed) were then subjected to tensile, flexural and low-velocity falling weight impact tests. It was observed from the experimental results that the moisture uptake significantly influenced the mechanical properties of the biocomposites. The presence of the cork and paper in sample C made it more susceptible to water absorption, reaching a value of 34.33%. The presence of cork in the core also has a considerable effect on the mechanical, as well as energy dissipation, behaviours. The results of sample A exhibited improved mechanical performance in both dry and wet conditions compared to samples B and C. Sample A exhibits 32.6% more tensile strength and 81.4% more flexural strength in dry conditions than that in sample C. The scanning electron microscopy (SEM) and X-ray micro-CT images revealed that the failure modes observed are a combination of matrix cracking, core crushing and face core debonding. The results from this study suggest that flax/PLA sandwich biocomposites can be used in various lightweight applications with improved environmental benefits.

Metallic biomaterials are widely used for implants and dental and orthopedic applications due to their good mechanical properties. Among all these materials, 316L stainless steel has gained special attention, because of its good characteristics as an implantable biomaterial. However, the Young’s modulus of this metal is much higher than that of human bone (~193 GPa compared to 5–30 GPa). Thus, a stress shielding effect can occur, leading the implant to fail. In addition, due to this difference, the bond between implant and surrounding tissue is weak. Already, calcium phosphate ceramics, such as beta-tricalcium phosphate, have shown excellent osteoconductive and osteoinductive properties. However, they present low mechanical strength. For this reason, this study aimed to combine 316L stainless steel with the beta-tricalcium phosphate ceramic (β-TCP), with the objective of improving the steel’s biological performance and the ceramic’s mechanical strength. The 316L stainless steel/β-TCP biocomposites were produced using powder metallurgy and functionally graded materials (FGMs) techniques. Initially, β-TCP was obtained by solid-state reaction using powders of calcium carbonate and calcium phosphate. The forerunner materials were analyzed microstructurally. Pure 316L stainless steel and β-TCP were individually submitted to temperature tests (1000 and 1100 °C) to determine the best condition. Blended compositions used to obtain the FGMs were defined as 20% to 20%. They were homogenized in a high-energy ball mill, uniaxially pressed, sintered and analyzed microstructurally and mechanically. The results indicated that 1100 °C/2 h was the best sintering condition, for both 316L stainless steel and β-TCP. For all individual compositions and the FGM composite, the parameters used for pressing and sintering were appropriate to produce samples with good microstructural and mechanical properties. Wettability and hemocompatibility were also achieved efficiently, with no presence of contaminants. All results indicated that the production of 316L stainless steel/β-TCP FGMs through PM is viable for dental and orthopedic purposes.

The paper presents a procedure of the manufacturing and complex analysis of the properties of injection mouldings made of polymeric composites based on the poly(butylene succinate) (PBS) matrix with the addition of a natural filler in the form of wheat bran (WB). The scope of the research included measurements of processing shrinkage and density, analysis of the chemical structure, measurements of the thermal and thermo-mechanical properties (Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TG), Heat Deflection Temperature (HDT), and Vicat Softening Temperature (VST)), and measurements of the mechanical properties (hardness, impact strength, and static tensile test). The measurements were performed using design of experiment (DOE) methods, which made it possible to determine the investigated relationships in the form of polynomials and response surfaces. The mass content of the filler and the extruder screw speed during the production of the biocomposite granulate, which was used for the injection moulding of the test samples, constituted the variable factors adopted in the DOE. The study showed significant differences in the processing, thermal, and mechanical properties studied for individual systems of the DOE.

This study aimed to prepare microcrystalline cellulose (MCC) films with good mechanical properties via plasticization using a Chinese leek (CL, Allium tuberosum) extract. The microstructure, crystal structure, mechanical properties, barrier ability, and thermal properties of the films were investigated. The chemical structure analysis of CL extract showed the existence of cellulose, lignin, and low-molecular-weight substances, such as polysaccharides, pectins, and waxes, which could act as plasticizers to enhance the properties of MCC:CL biocomposite films. The results of scanning electron microscopy and atomic force microscopy analyses indicated the good compatibility between MCC and CL extract. When the volume ratio of MCC:CL was 7:3, the MCC:CL biocomposite film exhibited the best comprehensive performance in terms of water vapor permeability (2.11 × 10–10 g/m·s·Pa), elongation at break (13.2 ± 1.8%), and tensile strength (24.7 ± 2.5 MPa). The results of a UV absorption analysis demonstrated that the addition of CL extract improved the UV-shielding performance of the films. Therefore, this work not only proposes a facile method to prepare MCC films with excellent mechanical properties via plasticization using CL extract but also broadens the potential applications of MCC films in the packaging area.

Each year, more than 330 million tons of plastic are produced worldwide. The main consumers of plastics are the packaging (40%), building (20%) and automotive (8%) industries, as well as for the manufacture of household appliances. The vast majority of industrial plastics are not biodegradable and, therefore, create environmental problems due to the increase in the amount of solid waste. Studies have been conducted to produce biodegradable materials such as bioplastics to overcome this environmental problem. Bioplastics are defined as materials that are bio-based, biodegradable, or both; they can provide excellent biodegradability and can be used to help alleviate environmental problems. Therefore, this article presents an overview of the introduction of bioplastic materials and classifications, and a comprehensive review of their drawbacks and areas of importance, including basic and applied research, as well as biopolymer mixtures and biocomposites developed in the last decade. At the same time, this article provides insights into the development of bioplastics research to meet the needs of many industries, especially in the packaging industry in Malaysia. This review paper also focuses generally on bioplastic packaging applications such as food and beverage, healthcare, cosmetics, etc.

In this work, biocomposite blown films based on poly(butylene adipate-co-terephthalate) (PBAT) as biopolymeric matrix and biochar (BC) as filler were successfully fabricated. The materials were subjected to a film-blowing process after being compounded in a twin-screw extruder. The preliminary investigations conducted on melt-mixed PBAT/BC composites allowed PBAT/BC 5% and PBAT/BC 10% to be identified as the most appropriate formulations to be processed via film blowing. The blown films exhibited mechanical performances adequate for possible application as film for packaging, agricultural, and compost bags. The addition of BC led to an improvement of the elastic modulus, still maintaining high values of deformation. Water contact angle measurements revealed an increase in the hydrophobic behavior of the biocomposite films compared to PBAT. Additionally, accelerated degradative tests monitored by tensile tests and spectroscopic analysis revealed that the filler induced a photo-oxidative resistance on PBAT by delaying the degradation phenomena.

In this work, for the first time, the influence of the coordination environment as well as Ca and P atomic states on biomimetic composites integrated with dental tissue was investigated. Bioinspired dental composites were synthesised based on nanocrystalline calcium carbonate-substituted hydroxyapatite Ca4ICa6IIPO46−xCO3x+yOH2−y (nano-cHAp) obtained from a biogenic source and a set of polar amino acids that modelled the organic matrix. Biomimetic composites, as well as natural dental tissue samples, were investigated using Raman spectromicroscopy and synchrotron X-ray absorption near edge structure (XANES) spectroscopy. Molecular structure and energy structure studies revealed several important features related to the different calcium atomic environments. It was shown that biomimetic composites created in order to reproduce the physicochemical properties of dental tissue provide good imitation of molecular and electron energetic properties, including the carbonate anion CO32− and the atomic Ca/P ratio in nanocrystals. The features of the molecular structure of biomimetic composites are inherited from the nano-cHAp (to a greater extent) and the amino acid cocktail used for their creation, and are caused by the ratio between the mineral and organic components, which is similar to the composition of natural enamel and dentine. In this case, violation of the nano-cHAp stoichiometry, which is the mineral basis of the natural and bioinspired composites, as well as the inclusion of different molecular groups in the nano-cHAp lattice, do not affect the coordination environment of phosphorus atoms. The differences observed in the molecular and electron energetic structures of the natural enamel and dentine and the imitation of their properties by biomimetic materials are caused by rearrangement in the local environment of the calcium atoms in the HAp crystal lattice. The surface of the nano-cHAp crystals in the natural enamel and dentine involved in the formation of bonds with the organic matrix is characterised by the coordination environment of the calcium atom, corresponding to its location in the CaI position—that is, bound through common oxygen atoms with PO4 tetrahedrons. At the same time, on the surface of nano-cHAp crystals in bioinspired dental materials, the calcium atom is characteristically located in the CaII position, bound to the hydroxyl OH group. The features detected in the atomic and molecular coordination environment in nano-cHAp play a fundamental role in recreating a biomimetic dental composite of the natural organomineral interaction in mineralised tissue and will help to find an optimal way to integrate the dental biocomposite with natural tissue.

Funding Information: This work was supported by Jenny and Antti Wihuri Foundation (Centre for Young Synbio Scientists). A.M. acknowledges financial support from the Singapore Ministry of Education through an Academic Research Fund Tier 3 grant (# MOE 2019‐T3‐1‐012). The authors would like to also acknowledge Academy of Finland's Photonics Research and Innovation (PREIN) flagship. The authors thank Daniel Werner and Ernesto Scoppola (Max Planck Institute of Colloids and Interfaces) for help with µCT‐ and synchrotron scattering experiments. Publisher Copyright: © 2021 The Authors. Advanced Materials published by Wiley-VCH GmbH Nature provides unique insights into design strategies evolved by living organisms to construct robust materials with a combination of mechanical properties that are challenging to replicate synthetically. Hereby, inspired by the impact-resistant dactyl club of the stomatopod, a mineralized biocomposite is rationally designed and produced in the complex shapes of dental implant crowns exhibiting high strength, stiffness, and fracture toughness. This material consists of an expanded helicoidal organization of cellulose nanocrystals (CNCs) mixed with genetically engineered proteins that regulate both binding to CNCs and in situ growth of reinforcing apatite crystals. Critically, the structural properties emerge from controlled self-assembly across multiple length scales regulated by rational engineering and phase separation of the protein components. This work replicates multiscale biomanufacturing of a model biological material and also offers an innovative platform to synthesize multifunctional biocomposites whose properties can be finely regulated by colloidal self-assembly and engineering of its constitutive protein building blocks.

International audience; A composite based on hydroxyapatite (HA) and chitosan (CS) combined with ciprofloxacin (CIP) was formulated by the solid-liquid mixing method. The optimization of the solid to the liquid ratio and the use of chitosan in a small amount (

In the current investigation, a biocomposite with lotus stem as natural fiber reinforcement and epoxy resin was fabricated. Parafin wax was used a Phase Change Material (PCM) in the current investigation for thermal energy storage application along with the prepared biocomposite. The lotus steams were collected, dried and prepared for the required size. PCM was impregnated into the lotus stem by wax impregnation process to improve its thermal energy storage capacity. Then lotus fiber impregnated with wax was used as reinforcement in the prepared composite with epoxy resin. Totally 6 numbers of biocomposite plates were fabricated in order to fabricate a cuboid block. The Thermogravimetric analysis (TGA), Fourier Transform Infrared Spectroscopy (FT-IR) Test and thermal behaviour test were conducted to characterize the prepared bio composite material about its viability and behaviour towards energy storage application. The cuboid block formed with bio-composite was insulated with thermocol ice box to test the energy storage capacity. The energy storage capacity of the composite was determined using ice and equivalent mass of water placed inside the cuboid. While analyzing thermal behaviour test, it has been absorbed that the energy storing capacity of single plate of bio-composite was 13.08 kJ and thermal energy storing capacity of bio composite cuboid block was 19.22 kJ.

Biocomposite materials create a huge opportunity for a healthy and safe environment by replacing artificial plastic and materials with natural ingredients in a variety of applications. Furniture, construction materials, insulation, and packaging, as well as medical devices, can all benefit from biocomposite materials. Wheat is one of the world’s most widely cultivated crops. Due to its mechanical and physical properties, wheat starch, gluten, and fiber are vital in the biopolymer industry. Glycerol as a plasticizer considerably increased the elongation and water vapor permeability of wheat films. Wheat fiber developed mechanical and thermal properties as a result of various matrices; wheat gluten is water insoluble, elastic, non-toxic, and biodegradable, making it useful in biocomposite materials. This study looked at the feasibility of using wheat plant components such as wheat, gluten, and fiber in the biocomposite material industry.

Biopolymer-based slow-release fertilizers (SRFs) have attracted increasing interest because of their environmental benefits. Herein, a hydrophobic thermoplastic lignin with favorable film formation properties was synthesized through simple crosslinking followed by esterification reactions. The chemical structure, glass transition temperature, and hydrophobicity were determined using Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance spectroscopy, differential scanning calorimetry, and contact angle studies. The newly synthesized esterified crosslinked sodium lignosulfonate (ECSL) enables the encapsulation of urea via a solvent-free coating method to prepare SRFs because of its appropriate glass transition temperature (Tg) and excellent film formation properties. The ECSL-based SRF released only 86.9% of the encapsulated urea within 44 d, which is superior to most lignin-based SRFs in previous studies. The release rate can also be tuned by adjusting the ECSL ratio. The synthesis of hydrophobic lignin biocomposites with suitable Tgs for film formation resolves the bottleneck of using these types of non-thermoplastic polymers (e.g., lignin) for SRFs. This study not only maximizes the value of biowaste lignin but also offers a non-paradigm approach toward low-cost SRFs for sustainable agriculture.

This work reports the effects of free volume on curcumin release in various polymer-based composite films. Curcumin-reinforced biocomposite films were fabricated with natural biopolymers (carrageenan and chitosan) and bioplastics (poly(lactide) (PLA) and poly (butylene adipate-co-terephthalate) (PBAT)) via the solvent casting method. The curcumin release test was performed using an aqueous medium, and it was found that it was released the fastest in the carrageenan film, followed by the chitosan, PLA, and PBAT films, presumably owing to the dissimilarity of the polymer matrix. The free volume of the polymer films was determined using positron annihilation lifetime spectroscopy (PALS) to understand the release phenomena of curcumin. The free volume fraction was varied and reliant on the type of polymer, with the highest in the PBAT-based film followed by the PLA-, chitosan-, and carrageenan-based films. The free volume method helps analyze the release of bioactive compounds in a polymer matrix and may help to achieve a better understanding of the release of bioactive compounds.

The investigation of renewable and recyclable materials becomes more critical every day due to the high levels of waste and carbon emissions and their impact on the environment. The use of eco-friendly materials, such as natural fibers and bioplastics, is increasingly important, and their use is always more popular. The aim of this research is to evaluate the changes in properties of composite materials made of Poly-Butyl-Succinate (PBS), a biodegradable thermoplastic matrix, and carbon fiber when some layers of carbon fiber are replaced by some layers of flax fiber to create a hybrid composite; in order to obtain a material more environmentally friendly with similar mechanical properties. To modify the flax fiber’s surface energy and improve the wettability with the PBS matrix, an Atmospheric Pressure Plasma Torch (APPT) treatment was performed. The fibers’ surfaces were characterized by measuring the contact angle; the contact angle values confirmed the wettability and accordingly, adhesion increased after plasma treatment. Different experiments were performed after substituting carbon fibers to evaluate the changes in the composite material’s mechanical and thermal properties: tensile test, threepoint bending test, impact tests and differential scanning calorimetry. Replacing the carbon fiber core layer with one or two flax fiber layers did not compromise the thermal stability. It led to the manufacturing of a hybrid composite with improved mechanical properties and higher impact resistance. This work has been supported by Comunidad de Madrid (Spain) - multiannual agreement with UC3M ("Excelencia para el Profesorado Universitario"; - EPUC3M04) - Fifth regional research plan 2016-2020

Biochar obtained from the oxygen-deficient thermochemical processing of organic wastes is considered to be an effective reinforcing agent in biocomposite development. In the present research, biocomposite film was prepared using sugarcane bagasse pyrolyzed biochar and polyvinyl alcohol (PVA), and its electrical and mechanical properties were assessed. The biocomposite films were produced by varying content (5 wt.%, 8 wt.% and 12 wt.%) of the biochar produced at 400 °C, 600 °C, 800 °C and 1000 °C and characterized using X-Ray diffraction, scanning electron microscope, Fourier transform infrared spectroscopy. The experimental findings revealed that biochar produced at a higher pyrolyzing temperature could significantly improve the electrical conductance of the biocomposite film. A maximum electrical conductance of 7.67 × 10−2 S was observed for 12 wt.% addition of biochar produced at 1000 °C. A trend of improvement in the electrical properties of the biocomposite films suggested a threshold wt.% of the biochar needed to make a continuous conductive network across the biocomposite film. Rapid degradation of tensile strength was observed with an increasing level of biochar dosage. The lowest tensile strength 3.12 MPa was recorded for the film with 12 wt.% of biochar produced at 800 °C. Pyrolyzing temperature showed a minor impact on the mechanical strength of the biocomposite. The prepared biocomposites could be used as an electrically conductive layer in electronic devices.

Biocomposites based on thermoplastic polymers and natural fibers have recently been used in wind turbine blades, to replace non-biodegradable materials. In addition, carbon nanofillers, including carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs), are being implemented to enhance the mechanical performance of composites. In this work, the Mori–Tanaka approach is used for homogenization of a polymer matrix reinforced by CNT and GNP nanofillers for the first homogenization, and then, for the second homogenization, the effective matrix was used with alfa and E-glass isotropic fibers. The objective is to study the influence of the volume fraction Vf and aspect ratio AR of nanofillers on the elastic properties of the composite. The inclusions are considered in a unidirectional and random orientation by using a computational method by Digimat-MF/FE and analytical approaches by Chamis, Hashin–Rosen and Halpin–Tsai. The results show that CNT- and GNP-reinforced nanocomposites have better performance than those without reinforcement. Additionally, by increasing the volume fraction and aspect ratio of nanofillers, Young’s modulus E increases and Poisson’s ratio ν decreases. In addition, the composites have enhanced mechanical characteristics in the longitudinal orientation for CNT- reinforced polymer and in the transversal orientation for GNP-reinforced polymer.

In order to determine the structure homogeneity of biocomposites filled with fibers, as well as the evaluation of fibers’ arrangement and their orientation on the sample cross-section at varied injection rates, a study was conducted using computed tomography (CT). The main advantage of this test is the fact that in order to assess the microstructure on cross-sections, the samples do not have to be processed mechanically, which allows for presenting the actual image of the microstructure. The paper presents the issues of such tests for the biocomposite of poly (3-hydroxybutyric-co-3-hydroxyvaleric acid) (PHBV)-hemp fibers. It should be emphasized that CT scanning of PHBV-hemp fiber biocomposites is quite difficult to perform due to the similar density of the fibers and the polymer matrix. Due to the high difficulty of distinguishing fibers against the background of the polymer matrix during CT examination, a biocomposite containing 15% hemp fibers was analyzed. The samples for testing were manufactured using the injection molding process at variable injection rates, i.e., 10, 35 and 70 cm3/s. The images obtained by computed tomography show the distribution of hemp fibers and their clusters in the PHBV matrix and the degree of porosity on the sample cross-section. There were significant microstructural differences for the samples injected at the highest injection rates, including, among others, the occurrence of a smaller number of fibers and pores on the surface layer of the molded piece. The phenomenon observed was verified by testing chosen mechanical properties, shrinkage and water absorption of the samples. Some properties improved with an increasing injection rate, while others deteriorated and vice versa. An analysis of biocomposites’ microstructures using computed tomography provides a wide range of possibilities for future research, including an assessment of the structure of the molded parts. These tests may allow one, for example, to detect the cause of molded piece properties decreasing in a specific area as a result of a high degree of fiber disorientation, as well as the defects resulting from high porosity of the material. Such analyses can be particularly useful for producers that deal with the injection molding of pieces molded with specific properties.

A significant part of the work carried out so far in the field of production of biocomposite polyurethane foams (PUR) with the use of various types of lignocellulosic fillers mainly concerns rigid PUR foams with a closed-cell structure. In this work, the possibility of using waste wood particles (WP) from primary wood processing as a filler for PUR foams with open-cell structure was investigated. For this purpose, a wood particle fraction of 0.315–1.25 mm was added to the foam in concentrations of 0, 5, 10, 15 and 20%. The foaming course of the modified PUR foams (PUR-WP) was characterized on the basis of the duration of the process’ successive stages at the maximum foaming temperature. In order to explain the observed phenomena, a cellular structure was characterized using microscopic analysis such as SEM and light microscope. Computed tomography was also applied to determine the distribution of wood particles in PUR-WP materials. It was observed that the addition of WP to the open-cell PUR foam influences the kinetics of the foaming process of the PUR-WP composition and their morphology, density, compressive strength and thermal properties. The performed tests showed that the addition of WP at an the amount of 10% leads to the increase in the PUR foam’s compressive strength by 30% (parallel to foam’s growth direction) and reduce the thermal conductivity coefficient by 10%.

Natural and biodegradable polymers are of particular interest as green sources with low-cost and environmentally friendly features, and have been widely used for polymer composite development. The term “Green Composites” refers to polymer/filler systems in which polymer, filler, or sometimes both components are green in view of sources from which they are yielded or their biodegradability. Natural fibers obtained from plants, animals, and/or geological processes are a big class of green sources widely applied in green composite development. There has also been continued research on recycling of green composite as well as developing hybrid systems for advanced applications. In view of their outstanding biodegradability and biocompatibility in biological media, green composites are crucial elements in medicine. For instance, chitin, chitosan, alginate, and collagen are green polymers widely used for manufacturing composites for hard tissue repair. Several green composite polymers have been used for development of hard tissue implants such as artificial bone, bone cement, knee hip replacement, and spine instrumentation. This review attempts to classify and discuss applications of green composites in bone tissue engineering. Applications of different types of natural fiber biocomposite scaffolds for fractured bone repair were reviewed; besides, morphological structures of scaffolds were correlated with the mechanical properties of human bone.

International audience; In recent years the interest in the realization of green wood plastic composites (GWPC) materials has increased due to the necessity of reducing the proliferation of synthetic plastics. In this work, we study a specific class of GWPCs from its synthesis to the characterization of its mechanical properties. These properties are related to the underlying microstructure using both experimental and modeling approaches. Different contents of Miscanthus giganteus fibers, at 5, 10, 20, 30 weight percent’s, were thus combined to a microbial matrix, namely poly (3-hydroxybutyrate)-co-poly(3-hydroxyvalerate) (PHBHV). The samples were manufactured by extrusion and injection molding processing. The obtained samples were then characterized by cyclic-tensile tests, pycnometer testing, differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray diffraction, and microscopy. The possible effect of the fabrication process on the fibers size is also checked. In parallel, the measured properties of the biocomposite were also estimated using a Mori–Tanaka approach to derive the effective behavior of the composite. As expected, the addition of reinforcement to the polymer matrix results in composites with higher Young moduli on the one hand, and lower failure strains and tensile strengths on the other hand (tensile modulus was increased by 100% and tensile strength decreased by 23% when reinforced with 30 wt % of Miscanthus fibers).

The search for renewable alternatives for petroleum products that can be used in industrial applications is increasing. Each year, several tons of bio-derived industrial waste is produced and most of it is burned or placed in landfills. Olive pits (OP) have unique characteristics such as abundance, renewability, and biodegradability, which can be utilized to develop new types of biocomposites. One of the most promising uses of OP is that they can reinforce the mechanical properties of polymeric biocomposites. This study describes the preparation of recycled low-density polyethylene (rLDPE) that is filled with OP flour (10, 20, 30, and 40 wt.%) using a twin-screw extruder. The effects of the chemical treatment of the OP surface (sodium hydroxide (NaOH) and dimethyl sulfoxide (DMSO)) on the bio-filler/polymer compatibility along with the produced composite’s chemical, physical, mechanical, and thermal properties have been explored. Overall, the reinforced composites that were obtained with alkali-treated OP have better biocomposite properties. This indicates an improved compatibility between the bio-filler and matrix. The results are promising in terms of using OP flour in developing green composites.

Bone is a hierarchical material that has inspired the design of biopolymer-derived biocomposites for tissue engineering purposes. The present study sought to synthesize and perform the physicochemical characterization and biocompatibility of a collagen-silica-based biocomposite for potential application in bone tissue engineering. Ultrastructure, biodegradability, swelling behavior, and biocompatibility properties were analyzed to gain insight into the advantages and limitations to the use of this biomaterial as a bone substitute. Scanning electron microscopy analysis showed a packed-collagen fibril matrix and silica particles in the biocomposite three-dimensional structure. As shown by analysis of in vitro swelling behavior and biodegradability, it would seem that the material swelled soon after implantation and then suffered degradation. Biocompatibility properties were analyzed in vivo 14-days postimplantation using an experimental model in Wistar rats. The biocomposite was placed inside the hematopoietic bone marrow compartment of both tibiae (n = 16). Newly formed woven bone was observed in response to both materials. Unlike the pure-collagen-tissue interface, extensive areas of osseointegration were observed at the biocomposite-tissue interface, which would indicate that silica particles stimulated new bone formation. Agglomerates of finely particulate material with no inflammatory infiltrate or multinucleated giant cells were observed in the bone marrow implanted with the biocomposite. The biocomposite showed good biocompatibility properties. Further studies are necessary to evaluate their biological behavior over time. Fil: Alvarez Echazú, María Inés. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Analítica y Fisicoquímica. Cátedra de Química Analítica Instrumental; Argentina. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Anatomía Patológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Renou, Sandra Judith. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Anatomía Patológica; Argentina Fil: Alvarez, Gisela Solange. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; Argentina Fil: Desimone, Martín Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; Argentina Fil: Olmedo, Daniel Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Anatomía Patológica; Argentina