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The aim of the paper consist in the synthesis of double substituted carbonated hydroxyapatite using Zn2+ and Mg2+ ions in comparison with the previous obtained Sr-Zn-CHAp. Fourier transform infrared spectroscopy, X-ray diffraction, environmental scanning electron microscope (ESEM) coupled with EDS is used to highlight the presence of the metallic ions into the apatite structure. Both inorganic compounds are tested as consolidants for two types of fir wood, young and 30-years old samples. The consolidation efficiency is demonstrated by colorimetric analysis, mechanical tests and the specific methods for water absorption behavior. Stronger specimens, especially of young wood, with no significant color differences, more hygroscopic and with higher hysteresis index result after treatment. In conclusion, carbonated hydroxyapatite double substituted with zinc, magnesium and strontium ions can be used in wood preservation-conservation techniques.

There is an ever-growing interest in recovering and recycling waste materials due to their hazardous nature to the environment and human health. Recently, especially since the beginning of the COVID-19 pandemic, disposable medical face masks have been a major source of pollution, hence the rise in studies being conducted on how to recover and recycle this waste. At the same time, fly ash, an aluminosilicate waste, is being repurposed in various studies. The general approach to recycling these materials is to process and transform them into novel composites with potential applications in various industries. This work aims to investigate the properties of composites based on silico-aluminous industrial waste (ashes) and recycled polypropylene from disposable medical face masks and to create usefulness for these materials. Polypropylene/ash composites were prepared through melt processing methods, and samples were analyzed to get a general overview of the properties of these composites. Results showed that the polypropylene recycled from face masks used together with silico-aluminous ash can be processed through industrial melt processing methods and that the addition of only 5 wt% ash with a particle size of less than 90 µm, increases the thermal stability and the stiffness of the polypropylene matrix while maintaining its mechanical strength. Further investigations are needed to find specific applications in some industrial fields.

In this work, cellulose nanofibers (CNF) were surface treated by plasma and grafted with poly(ethylene glycol)methyl ether methacrylate (PEGMMA) for increasing mechanical strength and hydrophobicity. The surface characteristics of the sponges were studied by scanning electron microscopy, micro-computed tomography, and Fourier transform infrared spectroscopy, which demonstrated successful surface modification. Plasma treatment applied to CNF suspension led to advanced defibrillation, and the resulting sponges (CNFpl) exhibited smaller wall thickness than CNF. The grafting of PEGMMA led to an increase in the wall thickness of the sponges and the number of larger pores when compared with the non-grafted counterparts. Sponges with increased hydrophobicity demonstrated by an almost 4 times increase in the water contact angle and better mechanical strength proved by 2.5 times increase in specific compression strength were obtained after PEGMMA grafting of plasma treated CNF. Cells cultivated on both neat and PEGMMA-grafted CNF sponges showed high viability (>99%). Remarkably, CNF grafted with PEGMMA showed better cell viability as compared with the untreated CNF sample; this difference is statistically significant (p < 0.05). In addition, the obtained sponges do not trigger an inflammatory response in macrophages, with TNF-α secretion by cells in contact with CNFpl, CNF-PEGMMA, and CNFpl-PEGMMA samples being lower than that observed for the CNF sample. All these results support the great potential of cellulose nanofibers surface treated by plasma and grafted with PEGMMA for biomedical applications.

This paper aims with the preparation of Sr2+ and Zn2+ double substituted carbonated hydroxyapatite (Sr-Zn-CHAp) by the nanoemulsion method and to evaluate its consolidation capacity on artificial stone samples. The changes in CHAp lattice parameters were observed by a synergy between the shrinkage and dilatation induced by the two metallic ions, with different ionic radii by comparison with calcium. The changed morphology obtained by calcination was evidenced by SEM analysis. Also, the tendency to agglomerate of the double substituted CHAp as micron- and sub-micron-sized particles with spherical and irregular form was observed. The FTIR, XRD and EDS results confirmed that the CHAp was successfully substituted with Sr2+ and Zn2+ by replacing Ca2+ resulting a AB-type CHAp. The efficacity of Sr-Zn-CHAp as inorganic consolidant for the stone was tested by mechanical strength, resistance at freeze–thaw artificial aging test, thermal shock weathering, colorimetric changes of the artificial stone sample, all the results being correlated with the water absorption test, water repellency, and pore structure changes. By treating the stone with 0.5 g/L Sr-Zn-CHAp led to an improvement of the above-mentioned characteristics, without significant chromatic changes.

Agricultural waste is a valuable source of advanced materials. Cheap nanocellulose may be obtained from plum shells agricultural residues and further used instead of expensive nanocellulose as reinforcement in biopolymers. In this work, two types of nanocellulose, cellulose nanocrystals (CN) and cellulose nanofibers (CF), were isolated from plum seed shells using two different approaches. CN and CF from plum seed shells were used for the first time as reinforcing agents in a polylactic acid/poly(3-hydroxybutyrate) (PLA/PHB) matrix using a solvent casting method. The surface morphology, thermal (TG and DSC), static and dynamic mechanical (DMA) properties of the resulted biocomposite films were characterized and compared to the neat matrix. Atomic force microscopy—peak force quantitative nanomechanical mapping emphasized the influence of nanocellulose type upon the crystalline structure of PLA/PHB biocomposites and the dispersion of nanofibers/nanocrystals in the polymer matrix. Thermal and XRD analyses showed that the incorporation of CN increased the thermal stability and crystallinity of PLA/PHB biocomposite film. Young’s modulus and storage modulus of PLA/PHB/CN biocomposite were higher compared to that of PLA/PHB/CF showing the better reinforcing capability of CN compared to CF. This is consistent with the better dispersion of CN observed by PF QNM. The good effect of cellulose nanocrystals obtained from plum seed shells on the properties of PLA/PHB matrix highlights the potential of this cheap nanocellulose to obtain biocomposites in very advantageous conditions. This approach is proposed as an affordable and efficient tool to employ agricultural wastes as raw materials for high added-value products.

The present work is aimed at designing innovative hybrid materials endowed with magnetic features. To this end, polymer beads are used as matrix for the encapsulation of Magnetic Microparticles (MMPs). The inorganic part of developed hybrids consists of MMPs (i.e., magnetite- Fe3O4), whereas the organic part consists of two-component polymer beads, obtained using poly (acrylonitrile-co-methacrylic acid) and polyvinyl alcohol. Magnetite particles are characterized in terms of both particle size and zeta potential by Dynamic Light Scattering (DLS), while their crystallite size and phases are assessed by X-ray Diffraction. The developed innovative hybrid materials are fully characterized using the following techniques: Fourier Transform Infrared (FTIR) spectrometry; Thermogravimetric Analysis/ Differential Thermal Analysis (TG/DTA) and Scanning Electron Microscopy (SEM). Furthermore, their magnetic properties are assessed using a Vibrating Sample Magnetometer (VSM) and their capacity for adsorption of active principles. In this respect, resveratrol, a poorly soluble, bioactive compound, was chosen as model active principle and it was found that the developed hybrids may achieve an efficient binding of resveratrol.

Carbonated hydroxyapatite (CHAp) is an inorganic compound with various applications that presents better homogeneity and consolidating effect than HAp [1]. [...]

Siliceous natural nanomaterials, i.e., diatomaceous earth and natural zeolites, are biorational products, generally recognized as safe (GRAS) due to their large utilization as dietary supplement [1] and food/feed additive [2]. [...]

The inherent brittleness of poly(3-hydroxybutyrate) (PHB) prevents its use as a substitute of petroleum-based polymers. Low molecular weight plasticizers, such as tributyl 2-acetyl citrate (TAC), cannot properly solve this issue. Herein, PHB films were obtained using a biosynthesized poly(3-hydroxyoctanoate) (PHO) and a commercially available TAC as toughening agents. The use of TAC strongly decreased the PHB thermal stability up to 200 &deg, C due to the loss of low boiling point plasticizer, while minor weight loss was noticed at this temperature for the PHB-PHO blend. Both agents shifted the glass transition temperature of PHB to a lower temperature, the effect being more pronounced for TAC. The elongation at break of PHB increased by 700% after PHO addition and by only 185% in the case of TAC, this demonstrates an important toughening effect of the polymeric modifier. Migration of TAC to the upper surface of the films and no sign of migration in the case of PHO were highlighted by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) results. In vitro biocompatibility tests showed that all the PHB films are non-toxic towards L929 cells and have no proinflammatory immune response. The use of PHO as a toughening agent in PHB represents an attractive solution to its brittleness in the case of packaging and biomedical applications while conserving its biodegradability and biocompatibility.

Biodegradable and biocompatible poly (3-hydroxybutyrate) (PHB) is considered a good candidate for biomedical applications provided that its inherent brittleness and thermal stability are corrected. In this work, poly (3-hydroxyhexanoate-co-3-hydroxyoctanoate) (PHHO) and bacterial cellulose nanofibers (BC) were used as “soft” and “stiff” modifiers to improve PHB properties. PHHO (5–20 wt%) increased the thermal stability of PHB and PHB-BC composites. On the other hand, BC increased the glass transition and the crystallization temperature of PHB in the blends. The surface morphology of PHB was differently changed by the addition of PHHO and BC: a microporous surface morphology with many well spread pores was produced by the addition of PHHO (20–50 wt%) and a smoother surface by the addition of BC. Still, the surface morphology of PHB/PHHO blends, with homogenously spread submicronic pores, was not changed by BC. Thermal, structural and morphological investigations showed that BC nanofibers are mainly located in PHHO rich phase and at interface. PHB nanocomposite with 20 wt% PHHO showed balanced stiffness-toughness properties and excellent thermal stability, with the onset thermal degradation temperature higher than 270 °C. These properties and its porous surface morphology besides the inherent biodegradability and biocompatibility promote this nanocomposite as a valuable material for tissue engineering. It is remarkable that these favorable properties were obtained by a simple, easily controlled method without additional processes or additives.

The present paper studies the effect of polyaniline grafting on magnetite functionalized with aminopropyltrimethoxysilane. All the compounds were characterized by analytical techniques (X-ray fluorescence, X-ray diffraction, Fourier transform infrared spectroscopy, thermal analysis, Transmission electron microscopy), as well as by determining their magnetic properties. The electron microscopy analysis of the hybrids shows similar morphologies for all the samples. The presence of the iron atoms on the surface of the final product supports the idea of the existence of an inverted core-shell type structure, the more polar ferrite orienting itself towards water. The correlation between the maximum grafting probability and the maximum magnetization is evidenced, demonstrating the importance of the polymer grafting method on the magnetic properties.

Plum seed shells (PS) have been successfully used as a source for cellulose nanocrystals isolation. Alkali treatment or hot-water extraction and acid hydrolysis removed non-cellulosic components and released cellulose nanocrystals (CNC). CNC with different lengths between 100 and 800 nm and no more than 14 nm in height were detected by AFM. The crystallinity strongly increased after these treatments, from 38% for raw PS to 51% and 54% depending on the treatment, due to hemicelluloses and lignin removal. The results showed that a low-cost by-product of food industry can be converted into a valuable material, cellulose nanocrystals.

The influence of spore concentration on the ability of a Trichoderma consortium to colonize the Passiflora caerulea phyllosphere was evaluated by determining the effects of foliar treatments with two spore concentrations, in two repeated treatments, on the morphological, physiological, and ultrastructural characteristics, and on the yield and quality of P. caerulea. The studied crop quality features were related to its nutraceutical use: the accumulation of polyphenols and flavonoids, antioxidant activity, and effects on mouse fibroblast L929 cells. The Trichoderma consortium consisted of two strains, T. asperellum T36b and T. harzianum Td50b, and the concentrations used were 106 colony forming units (cfu)/mL and 108 cfu/mL. As a reference treatment, a commercial product that was based on herbs and algal extracts was used. As compared to the negative control, the treatment with the Trichoderma consortium at 108 cfu/mL concentration determines the accumulation of higher level of polyphenols and flavonoids and increased antioxidant activity. This enhancement of P. caerulea quality characteristics after treatment with the higher concentration of Trichoderma consortium was associated with larger leaves, increased number and size of chloroplasts, improved plant physiology characteristics, and an increased yield. The treatment with high concentration of Trichoderma consortium spores promotes phyllosphere colonization and benefits both crop yield and quality.

In the field of water depollution, considerable attention in past years was given to bio-based and [...]

Sol-gel derived organic-inorganic hybrid systems were obtained by applying alkaline-catalyzed co-hydrolysis and copolycondensation reactions of tetraethoxysilane (TEOS), methyltriethoxysilane (MTES), isobutyltriethoxysilane (IBTES), diethoxydimethylsilane (DMDES), and vinyltriethoxysilane (VTES), respectively, into a polymer latex functionalized with vinyltriethoxysilane (VTES). The properties of the latex hybrid materials were analyzed by FTIR, water contact angle, environmental scanning electron microscopy (ESEM), TEM and AFM analysis, respectively. FT-IR spectra confirmed that the chemical structures of the sol-gel derived organic-inorganic materials are changed as function of inorganic precursor and Si O Si networks are formed during the co-hydrolysis and copolycondensation reactions. The water contact angle on the sol-gel latex film containing TEOS + VTES increased to 135° ± 2 compared to 65° ± 5 for the blank latex, due VTES incorporation into latex material. TGA curves of hybrid sample modifies against neat polymer, the thermal stability being influenced by the presence of the inorganic partner. ESEM analysis showed that the latex hybrid films prepared with different inorganic precursors were formed and the Si-based polymers were distributed on the surface of the dried sol-gel hybrid films. TEM and AFM photos revealed that the latex emulsion morphology was modified due to the VTES incorporation into system.

Bacterial cellulose (BC) is a very promising material due to its high purity, good mechanical properties and thermal stability. Bacterial cellulose nanofibers (BCNF) in dry form could be used as reinforcements in hydrophobic polymer matrices like polylactic acid (PLA) or polyhydroxyalkanoates for biomedical applications. In this work, BCNF were obtained by simple eco-friendly mechanical treatments applied to BC pellicles, consisting in successive wet and dry mechanical disintegration steps or only wet mechanical disintegration followed by freeze drying. The defibrillation processes did not modify the allomorph composition of BC, characterized by the preponderance of Iα compared to Iβ form, but determined an increase of crystallinity, from 81% to 84–85%. Morphological investigations revealed that the pellicles were entirely disintegrated by the mechanical treatments. AFM Peak-Force Quantitative-Nanomechanical-Mapping revealed unexpected detachment of small fibers from the BC ribbons at regular intervals, which was proved so far only for cellulose nanofibers from plants. PLA composites obtained with these BCNF showed higher modulus with almost 30% compared to the matrix. Dried BCNF prepared by these eco-friendly approaches are good reinforcements for bionanocomposites for “in vivo” or “ex vivo” application, due to their high purity. Keywords: Bacterial cellulose, Nanofibers, Polymer nanocomposites, AFM, XRD

Tough and flexible dielectrics were prepared using graphite (G), a natural and low-cost resource, as filler in polystyrene-b-(ethylene-co-butylene)-b-polystyrene (SEBS) and maleinized SEBS (SEBS-MA) matrices. The disintegration of graphite in submicron particles was accomplished by the shear forces during the melt processing step and it was highlighted by atomic force microscopy. Simultaneous increase of tensile strain, strength and Young's modulus was noticed for SEBS/G and SEBS-MA/G composites compared to unfilled matrices, this remarkable feature being previously reported only for some nanocomposites. Moreover, an exponential variation of the dielectric permittivity with the volume fraction of G was obtained. Higher reinforcing efficiency and better dielectric properties were observed in SEBS-MA/G composites, compared to the corresponding SEBS/G composites, due to the stronger polymer–filler interface and better dispersion of graphite. This study brings new insights into nanolevel properties of SEBS composites and it opens new perspectives on high performance composites by using graphite instead of expensive graphene and efficient melt mixing process.

Cellulose nanofibers (CN) with high aspect ratio were obtained and their transverse modulus (Et) was determined for the first time by peak force (PF) QNM (quantitative nanomechanical mapping). The PF QNM value of Et (18.8 GPa) was comparable with that of cellulose determined by other methods. CN were used as reinforcements in starch/poly(vinyl alcohol) (S/PVA) cross-linked films and the influence of storage conditions on the properties of these films was investigated in this paper. It was found that over 4 wt%, CN form a real network and hinder starch recrystallization. CN determined a significant increase of strength and stiffness of S/PVA depending on storage conditions. Two fold increase of modulus was observed in thermal treated samples compared to fresh ones and the increase of both strength and modulus in samples exposed to humid atmosphere. PF QNM successfully explains the influence of moisture on the properties of the films exposed to humid atmosphere, emphasizing new well organized sub-micron amorphous formations on their surface. Starch films with 7 wt% CN showed strength and stiffness close to that of polyolefines (19.5 MPa and 1199 MPa, respectively), and can be seen as a low cost “green” substitute for application in food packaging and conservation.

Monolayer and bilayer coatings deposited on polypropylene (PP) surface were prepared by sol–gel process at room temperature. Monolayer coatings were produced from sol–gel acidic solutions, containing tetraethylorthosilicate (TEOS) and different co-precursors such as phenyltriethoxysilane (PhTES), octylmethyldimethoxysilane (OMDMS) and dodecyltriethoxysilane (DOTES). Bilayer coatings consist of one layer prepared in a similar way described for monolayer coatings, followed by a second layer, obtained from fluorinated silica nanoparticles dispersion. The fluorinated group has been confirmed by the presence of C F bonds along with network Si O Si vibrational mode. Water contact angle values registered for bilayer-coated polypropylene are higher, comparing with the reference (pristine PP) and with the monolayer-coated substrate, and varies as a function of the hydrophobic functional groups of the silica co-precursors: phenyl

The radical polymerization of aniline hydrochloride (ANIHCl) in the presence of ammonium persulfate was studied. 1D-Polyaniline (PANI) with fibrillar morphologies was obtained in the presence of anionic surfactants. The changes of the PANI-template structures in aqueous solution were studied using static fluorescence measurements. The dispersed PANI nanoparticles were characterized using dynamic light scattering, scanning electron microscopy (SEM), and Raman and Fourier transform infrared spectroscopies. The thermal analysis and the electrical conductivity of the dried samples were also performed. The fluorescence measurements indicated that nanocrystals of ANIHCl form in water complexes with the anionic surfactants at smaller concentrations than the critical micellar concentration. The same method revealed that other organic complexes with sulfonate groups do not induce an increase of the hydrophobic region due to short hydrocarbon tails. The SEM micrographs and Raman spectra revealed that the PANI nanofibers are compact and different compared to the nanoparticles prepared without surfactants.

Simultaneous influence of polypropylene-graft-maleic anhydride (MAPP) and silane-treated hemp fibers (HF) on morphology, thermal and mechanical properties of high-flow polypropylene (PP) modified with poly[styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS) was studied in this paper. The addition of SEBS reduced the efficiency of MAPP in PP composites with HF, thus silane-treated fibers (HFs) were used to improve polymer–fiber interface. Thermal stability of HF was improved after silane treatment and less than 2% weight loss was observed at 240 °C in composites with 30 wt% HF. Better dispersion of fibers and better efficiency in enhancing static and dynamic mechanical properties of PP, doubling its strength and stiffness were observed in composites with treated fibers compared to untreated ones. High ability to absorb and dissipate energy and well-balanced strength and stiffness were showed by PP modified with SEBS and MAPP containing 30 wt% HFs. These composites were studied as an alternative to conventional PP/glass fibers composites for injection molding of small to medium auto parts.

The present paper was aimed at studying the possibility of zinc (Zn) removal from the wastewater discharged from zinc electroplating processes. In order to save industrial and environmental resources, the concentrated solution could be reused after electrodialysis process. A mini-electrodialysis system with three cylindrical compartments and different membranes containing various resins (Purolite A500 and Hypersol-Macronet MN500) was employed, which can be further applied for the treatment of synthetic effluent which contained zinc ions. The electrodialysis system was operated at constant voltage using different concentrations of synthetic solutions of zinc ions, without and with electrolyte recirculation for 1.5 h. The pH and conductivity of solutions were measured before and after the electrodialysis process occurs. Also the removal ratio (Rr) and mass flow (J) of zinc ions, energy consumption (EC) and current efficiency (CE) were determined. It was found that electrodialysis treatment generated a very low conductivity solution, enabling its reuse as rinse water. According to the obtained results when using a membrane pair with higher ion exchange capacity (IEC) the removal ratio is improved (over 80%). The physico-chemical, structural and mechanical properties of prepared membranes were registered, before and after electrodialysis process takes place, by means of complementary analytical techniques, namely, ion-exchange capacity, water content and thickness measurements. Furthermore analysis were also carried out by Fourier transform infrared spectroscopy (FT-IR), environmental scanning electron microscopy (ESEM), thermal gravimetric analysis (TGA) and electrochemical impedance spectroscopy (EIS).

In this research, both commercially available (Cloisite 93A) and advanced functionalized clay mineral were used to obtain clay–epoxy nanocomposites. Cloisite 93A was modified with three different alkoxysilanes and was incorporated in Epon 862 epoxy resin which was crosslinked using tetraethylenepentamine as a curing agent. The determination of color grades of the composite samples was followed. The morphology of the composites was analyzed using X-ray diffraction and ESEM micrographs which provided insight into the fracture mechanism. Thermal behavior was evaluated by TGA and DSC and thermo-mechanical properties of the cured samples have been evaluated by DMA technique. The data indicated that intercalated or agglomerated silylated Cloisite–epoxy nanocomposites were obtained. The silylated Cloisite samples are more compatible with the polymer matrix due to their enhanced hydrophobic behavior leading to an improvement in storage modulus and stiffness but also to the increase of glass transition temperature up to 30 °C.

We focused on preparing cellulose nanofibrils by purification, separation, and mechanical treatment of Kombucha membranes (KM) resulted as secondary product from beverage production by fermentation of tea broth with symbiotic culture of bacteria and yeast (SCOBY). We purified KM using two alkaline solutions, 1 and 4 M NaOH, which afterwards were subjected to various mechanical treatments. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), dynamic light scattering (DLS), X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA) were employed to evaluate the purification degree, the size and aspect of cellulose fibrils after each treatment step, the physical-chemical properties of intermediary and final product, and for comparison with micro-crystalline cellulose from wooden sources. We determined that 1 M NaOH solution leads to approx. 85% purification, while a higher concentration assures almost 97% impurities removal. XRD analysis evidenced an increase in crystallinity from 37% to 87% after purification, the characteristic diffractograms of Iα and Iβ cellulose allomorphs, and a further decrease in crystallinity to 46% after microfluidization, fact correlated with a drastically decrease in fibrils’ size. FTIR analysis evidenced the appearance of new chain ends by specific transmission bands at 2941 and 2843 cm−1.

The application of selenium (Se) to tomatoes enhances accumulation of bioactive compounds. The physiological window of Se is very narrow, and Se overdose reduces the yield. Glycine betaine was shown to reduce Se’s negative effects on plants and to potentiate its beneficial effects. In this study, baker’s yeast vinasse (BYV), as an affordable source of glycine betaine, was tested for its interaction with Se in an optimized foliar fertilizer. The application dose was selected after a laboratory experiment, wherein assays on plant height, leaves surfaces, stomatal conductance, and chlorophyll fluorescence were done. The Se and BYV supplemented foliar fertilizers were tested for their effects on accumulation of bioactives in drip-irrigated tomatoes cultivated in a greenhouse. Under laboratory conditions, assays demonstrated Se and BYV induced effects on tomatoes plants. Both the stomatal conductance and photosynthesis efficiency increased compared to a water treated control. The greenhouse experiment demonstrated that BYV and Se addition increases the number of tomato fruits in the “extra” marketable class and enhances the accumulation of ascorbic acid, carotenes, polyphenols, and flavonoids. The effects depend on the composition of the foliar fertilizer, the most significant effects being recorded for the foliar applied product with the highest BYV and nitrogen content.

The effect of orientation induced during the manufacturing process on the self-assembled morphology and mechanical properties of poly(styrene-b-ethylene/butylene-b-styrene) block copolymer (SEBS), maleated SEBS (SEBS-MA) and their composites with graphite was examined in this paper. The roll milling process induced higher stiffness along the rolling direction, emphasized by the increase of Young’s modulus with 645% in this direction relative to the perpendicular one and the increase of storage modulus at room temperature with one order of magnitude. The addition of graphite particles diminished the anisotropy of static and dynamic mechanical properties but contributed to the increase of the total energy absorbed till break. The different self-assembled morphologies and degree of order observed by polarized optical microscopy (POM), scanning electron microscopy (SEM) and atomic force microscopy (AFM) in SEBS and SEBS-MA explained some of the differences in their static and dynamic mechanical behavior. For the first time the anisotropy was emphasized by the different glass transition values obtained on the two stretching directions.

The aim of this paper was to prepare composites of bacterial cellulose (BC) and collagen to evaluate both the effect of collagen on the morphological, mechanical and thermal properties of BC and the effect of BC on the thermal stability of collagen for designing composites with increased potential biomedical applications. Two series of composites were prepared, the first series by immersing BC pellicle in solutions of collagen obtained in three forms, collagen gel (CG), collagen solution (CS) and hydrolysed collagen (HC), followed by freeze drying; and the second series of composites by mixing BC powder in solutions of collagen (CG, CS and HC), also followed by freeze drying. The properties of obtained composites were evaluated by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), mechanical tests, scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results revealed that BC acts as a thermal stabilizer for CS matrix, while with CG matrix it interacts synergistically leading to composites with improved properties. On the other hand, the BC sheet impregnated with collagen has a significantly improved thermal stability. Collagen (as HC, CS or CG) has also a positive influence on the mechanical properties of lyophilized BC sheet. A four times increase of modulus was observed in BC/HC and BC/CG composites. and an increase of 60 times for BC/CS. The spectacular increase of elastic modulus and tensile strength in the case of BC/CS composite was explained by the easier penetration of collagen solution in the BC network and impregnation of BC fibrils as revealed by SEM and AFM analyzes.

The increased interest in silica nanowires for nanophotonics, mechanical applications, microsurgery, chemical and biological sensors strongly motivates the search for new discoveries involving complex silica nanowire-clay mineral layers (SiNW), particularly focusing on their growth mechanism, their involvement during polymer synthesis and the generation of a new class of polymer nanocomposites. This paper addresses the major findings involving the growth mechanism of silica nanowires on the clay mineral layers as well as their high segmental mobility and influence on the kinetics of butylacrylate mini-emulsion radical polymerisation. The growth mechanism for the silica nanowires was a sol-gel process involving tetraethylorthosilicate at the edge groups of the clay layers after blocking the reactive sites with a monofunctional alkoxysilane. To demonstrate the mobility of the network, an indirect method was utilised, specifically the interaction between the ethoxylated molecules and Tween 60. No cross-linking side effects occurred in the silica nanowires. SiNW enhance the free radical polymerisation of butylacrylate in dispersed media, increasing the monomer conversion from 2.5% to 33%. The kinetics of the polymerisation process can be tuned by SiNW, modulating the system between emulsion- and mini-emulsion-like systems by acting on the pseudo-steady state interval of the radicals (10%–40% conversion).