Degree Of Crystallinity Research Articles

Effect of Bismuth Ferrite Nanoparticles on Physicochemical Properties of Polyvinylidene Fluoride-Based Nanocomposites

Bismuth ferrite (BiFeO3, BFO) is one of the few single-phase crystalline compounds exhibiting strong multiferroic properties at room temperature, which makes it promising for use in various fields of science and technology. The remarkable characteristics of BFO at the nanoscale position it as a compelling candidate for enhancing the functionalities of polymeric nanocomposite materials. In this study, we explore the fabrication of polyvinylidene fluoride (PVDF) nanocomposites with a variable content of BFO nanopowders (0, 5, 10, 15, 20, and 25 wt%) by solution casting in the form of thin films with the thickness of ~60 µm. Our findings reveal that the presence of BFO nanoparticles slightly facilitates the formation of β- and γ-phases of PVDF, known for their enhanced piezoelectric properties, thereby potentially expanding the utility of PVDF-based materials in sensors, actuators, and energy harvesting devices. On the other hand, the increase in filler concentration leads to enlarged spherulite diameter and porosity of PVDF, as well as an increase in filler content above 20 wt% resulting in a decrease in the degree of crystallinity. The structural changes in the surface were found to increase the hydrophobicity of the nanocomposite surface. Magnetometry indicates that the magnetic properties of nanocomposite are influenced by the BFO nanoparticle content with the saturation magnetization at ~295 K ranging from ~0.08 emu/g to ~0.8 emu/g for samples with the lowest and higher BFO content, respectively.

From Field to Pharmacy: Isolation, Characterization and Tableting Behaviour of Microcrystalline Cellulose from Wheat and Corn Harvest Residues.

A lack of strategies for the utilization of harvest residues (HRs) has led to serious environmental problems due to an accumulation of these residues or their burning in the field. In this study, wheat and corn HRs were used as feedstock for the production of microcrystalline cellulose (MCC) by treatment with 2-8% sodium hydroxide, 10% hydrogen peroxide and further hydrolysis with 1-2 M hydrochloric acid. The changes in the FT-IR spectra and PXRD diffractograms after chemical treatment confirmed the removal of most of the lignin, hemicellulose and amorphous fraction of cellulose. A higher degree of crystallinity was observed for MCC obtained from corn HRs, which was attributed to a more efficient removal of lignin and hemicellulose by a higher sodium hydroxide concentration, which facilitates the dissolution of amorphous cellulose during acid hydrolysis. MCC obtained from HRs exhibited lower bulk density and poorer flow properties but similar or better tableting properties compared to commercial MCC (CeolusTM PH101). The lower ejection and detachment stress suggests that MCC isolated from HRs requires less lubricant compared to commercial MCC. This study showed that MCC isolated from wheat and corn HRs exhibits comparable tableting behaviour like commercial sample, further supporting this type of agricultural waste utilization.

Preparation and characterization of microcrystalline cellulose from rice bran.

Rice bran, a by-product of rice processing, has not been fully utilized except for the small amount used for raising animals. The raw material source requirements of microcrystalline cellulose are becoming increasingly extensive. However, the characteristics of preparing microcrystalline cellulose from rice bran have not been reported, which limits the application of rice bran. Microcrystalline cellulose was obtained from rice bran by alkali treatment, delignification, bleaching and acid hydrolysis. The morphology, particle size distribution, degree of polymerization, crystallinity, and thermal stability of rice bran microcrystalline cellulose were analyzed. The chemical compositions, scanning electron microscopy and Fourier-transform infrared analysis for rice bran microcrystalline cellulose showed that the lignin and hemicellulose were successfully removed from the rice bran fiber matrix. The morphology of rice bran microcrystalline cellulose was shown to be of a short rod-shaped porous structure with an average diameter of 65.3 μm. The polymerization degree of rice bran microcrystalline cellulose was 150. The X-ray diffraction pattern of rice bran microcrystalline cellulose showed the characteristic peak of natural cellulose (type I), and its crystallization index was 71%. The rice bran microcrystalline cellulose may be used in biological composites with temperatures between 150 °C and 250 °C. These results suggest the feasibility of using rice bran as a low-price source of microcrystalline cellulose. © 2024 Society of Chemical Industry.

Energy-size relationship and starch modification in planetary ball milling of quinoa

The effects of speed (250–450 rpm) and time (10–50 min) on milling energy (E), particle size distribution (PSD), crystallinity degree (CD), damaged starch (DS), microstructure, hydration and pasting properties of flours obtained in a planetary ball mill (PBM) were investigated. As increasing milling severity quinoa flours showed polydispersed PSD (peaks at 417, 40 and 2 μm) with a shift towards smaller size and greater dispersion (Span: 3.0–5.2) as well as particles with rounded edges and polished surfaces (SEM images). The relationship E − D50 were satisfactorily predicted by the Walker's equation. The hydration tests as function of temperature and milling conditions revealed a complex flour behavior due to differences in PSD, composition, and DS content. The increasing milling energy caused a decrease in peak viscosity (PV), trough viscosity (TV) and final viscosity (FV) of up to 36%, 29%, and 25%, respectively. Significant correlations between flour attributes were found (DS-CD, r = −0.83, p < 0.01; PV-D50, r = 0.92, p < 0.01; TV-D50, r = 0.94, p < 0.01; FV-D50, r = 0.90, p < 0.01) denoted the increase of starch degradation as milling severity rises. These results can be used to improve the manufacture and the selection criteria of quinoa flour with specific functional attributes.

Entropy-Driven Crystallization of Hard Colloidal Mixtures of Polymers and Monomers.

The most trivial example of self-assembly is the entropy-driven crystallization of hard spheres. Past works have established the similarities and differences in the phase behavior of monomers and chains made of hard spheres. Inspired by the difference in the melting points of the pure components, we study, through Monte Carlo simulations, the phase behavior of athermal mixtures composed of fully flexible polymers and individual monomers of uniform size. We analyze how the relative number fraction and the packing density affect crystallization and the established ordered morphologies. As a first result, a more precise determination of the melting point for freely jointed chains of tangent hard spheres is extracted. A synergetic effect is observed in the crystallization leading to synchronous crystallization of the two species. Structural analysis of the resulting ordered morphologies shows perfect mixing and thus no phase separation. Due to the constraints imposed by chain connectivity, the local environment of the individual spheres, as quantified by the Voronoi polyhedron, is systematically more spherical and more symmetric compared to that of spheres belonging to chains. In turn, the local environment of the ordered phase is more symmetric and more spherical compared to that of the initial random packing, demonstrating the entropic origins of the phase transition. In general, increasing the polymer content reduces the degree of crystallinity and increases the melting point to higher volume fractions. According to the present findings, relative concentration is another determining factor in controlling the phase behavior of hard colloidal mixtures based on polymers.

Towards the Reuse of Fire Retarded Polyamide 12 for Laser Sintering.

The control of powder aging during Selective Laser Sintering (SLS) processing is one of the challenges to be overcome for the implementation of this technique in serial production. Aging phenomena, because of the elevated temperatures and long processing times, need to be considered when a fraction of the polymer powders present in the build chamber and not used to manufacture the parts are reused at various times. The aim of this study was to investigate the influence of successive reuse of blends of pure Polyamide 12 and its blends with two types of flame retardants (FR): ammonium polyphosphate (APP) and zinc borate (ZB). The composition of the blends was 70/30 (wt/wt) PA 12/FR. Four successive processing stages have been carried out by collecting the remaining powder blend each time. The powders were re-used using the same processing parameters after sieving. DSC measurements showed that the incorporation of FRs entailed a reduction in the processing window up to 4 °C; nevertheless, no further reduction was noted after aging. The TGA curves of aged blends of powders were also similar for pure PA 12 and PA 12 with FR. In addition, initial and reused powders presented a higher degree of crystallinity than the specimens processed from the powders. The heterogeneous character of the PA 12 after LS processing or reprocessing was shown through Pyrolysis Combustion Flow Calorimetry (PCFC) and cone calorimeter (CC) tests. FTIR analysis also showed that post-condensation reactions have occurred. The mode of action of the flame retardants was clearly seen on HRR curves at both tests. The first reuses of PA 12 powders entailed a significant reduction in time to ignition at the cone calorimeter (150 for the initial material to around 90 s for the reused material), indicating the formation of short polymer chains. Only in the case of zinc borate was it noticed that re-used powder was detrimental to the fire performance because of a strong increase in the value of pHRR (between 163 and 220 kW/m2 for reused material instead of 125 kW/m2 for the initial one).

Preparation and characterization of FeZrB amorphous ferrofluids as magnetic sizing agents for basalt fibers coating

In this paper, FeZrB amorphous nanoparticles were prepared and used to obtain a magnetic fluid which can be used as a magnetic sizing agent for basalt fibers. Unmodified FeZrB nanoparticles (Unmodified FeZrB), citric acid-modified FeZrB nanoparticles (FeZrB@CA) and sodium oleate-modified FeZrB nanoparticles (FeZrB@NaOL) were synthesised by chemical reduction. Three kinds of FeZrB magnetic sizing agents were obtained by dispersing nanoparticles into the mixture consisting of PVA and KH-550. The magnetic basalt fibers were prepared by spraying the magnetic sizing agents in the process of drawing basalt fibers. The structure, morphology, surface state and magnetic properties of unmodified and modified FeZrB amorphous nanoparticles were characterized by XRD, SEM, TEM, FT-IR and VSM. The properties of magnetic basalt fibers were investigated by SEM, VSM and EDS. The results showed that the XRD spectra showed sharp diffraction peaks in both Unmodified FeZrB and FeZrB@NaOL nanoparticles, and the two groups of samples had different degrees of crystallinity. Only a single broad peak can be observed at around 45° in FeZrB@CA, which confirms the amorphous structure of FeZrB@CA. SEM and TEM images show that the FeZrB amorphous nanoparticles exhibit spherical with sizes ranging from 7 nm to 25 nm. Electron diffraction patterns showed that FeZrB@CA had a diffraction halo typical of an amorphous structure, and the remaining two samples displayed diffraction rings, indicating some degree of crystallinity. The FT-IR spectra confirm the formation of CO bonds in both FeZrB@CA and FeZrB@NaOL nanoparticles, suggesting the successful modification of FeZrB nanoparticles. The saturation magnetization of Unmodified FeZrB, FeZrB@CA, and FeZrB@NaOL nanoparticles were determined as 83.4 emu/g, 98.9 emu/g, and 60.3 emu/g, respectively. The SEM images showed that the surface of fibers was completely covered by the magnetic sizing agents. Moreover, the saturation magnetization of BF-Unmodified FeZrB, BF-FeZrB@CA, BF-FeZrB@NaOL (magnetic basalt fibers) could reach 47.9 emu/g, 63.5 emu/g, and 28.9 emu/g, respectively. The formation mechanism of magnetic basalt fibers was elucidated, which is attributed to the SiO bonds between basalt fibers and KH-550, as well as CONH bonds between KH-550 and FeZrB@CA. Consequently, the FeZrB magnetic sizing agents could adhere to the fiber surface. This study provides a simple method for developing magnetic sizing agents and offers a new perspective for imparting magnetism to basalt fibers and preparing magnetic fibers.

A novel approach on artificial aging of nylon 12 powder for laser powder bed fusion

PurposeThis study aims to address challenges in the Laser Powder Bed Fusion process of polymers, focusing on the considerable amount of unsintered powder left post-printing. The objective is to understand the altered properties of this powder and find solutions to improve the process, reduce waste and explore reusing reprocessed powder.Design/methodology/approachA novel methodology is used to generate reprocessed powder without traditional printing, reducing time, cost and waste. The approach mimics the ageing effects during the printing process, providing insights into particle size distribution and thermal behaviour.FindingsResults reveal insights into artificial ageing, showing an 8.2% decrease in particle size (60.256–69.183 µm) and a 9.1% increase in particle size (17.378–19.953 µm) compared to unsintered powder. Thermal behaviour closely mirrors used powders, with variations in enthalpy of fusion (−0.55% to 2.69%) and degree of crystallinity (0.19% to 2.64%). The proposed methodology produces results that differ from those due to printing under 3% from a thermal point of view. The new process reduces the time needed for aged powder, contributing to cost savings and waste reduction.Originality/valueThe study introduces a novel method for reprocessed powder generation, deviating from traditional printing. The originality lies in artificially ageing powders, providing comparable results to actual printing. This approach offers efficiency, time savings and waste reduction in the Laser Powder Bed Fusion process, presenting a valuable avenue for further research.

Sustainable polymer reclamation: recycling poly(ethylene terephthalate) glycol (PETG) for 3D printing applications

Due to their versatile properties and wide-ranging applications across various industries, including manufacturing, polymers are indispensable for today’s society. However, polymer-based products significantly impact the environment since many are single-used plastics and require a long time to degrade naturally. A method to attenuate end-of-life polymers’ ill effects is recycling them to bring them again into the production cycle, from grave to cradle. This investigation involves recycling PETG sheets used in face shield production during the COVID-19 outbreak to fabricate 3D printing filaments for FFF. We assessed poly(ethylene terephthalate) glycol (PETG) processability to up to five recycling cycles and obtained filaments with properties adequate for 3D printing. Rheological, thermal, morphological, and mechanical characterization were analyzed to verify the effect of the number of processing cycles on the properties of the polymer. The recycling cycles originated a decrease in viscosity and elasticity, and the gain in molecular mobility resulted, relatively, in solids with a higher degree of crystallinity and prints with more elliptical depositions. The mechanical properties of printed parts fabricated of recycled material were comparable to those from commercial filament, especially after three extrusion cycles. Both extrusion and additive manufacturing processes successfully recycle material into filaments and printed parts, indicating that the proposed methodology is a promising alternative to bring value back to polymers from solid waste.

Grain Analysis of NCM Cathode Materials by ASTAR Technique and Its Effect on Battery Performance

Lithium-ion batteries (LIBs) are one of the most promising energy storage systems for portable electronic devices, electric vehicles, and renewable energy systems. Among the various cathode materials for LIBs, nickel cobalt manganese (NCM) oxide has attracted considerable attention due to its high specific capacity, good cycling stability, and appropriate cost for commercialization. However, Ni-rich NCM (Ni >80%) showed poor cyclability and huge gas evolution because of surface instability.Single crystal NCM has been suggested as a solution to these issues due to its excellent properties. However, it is difficult to quantify the degree of single crystallinity because it is so far subjective. In this study, we employed ASTAR technique (transmission electron microscopy combined with electron backscatter diffraction) to investigate the microstructural features of NCM cathode materials. Our ASTAR analysis showed that NCM cathode materials consist of complex grain and grain boundary structures with varying orientations and sizes. By analyzing the grain size and its morphology, we were able to define the single crystallinity of NCM cathode materials, including the poly NCM and single crystal NCM particles.Furthermore, we found that the grain size and its distribution significantly affects the battery performance and lifespan of NCM cathode materials. Specifically, the poly NCM particles exhibited a larger grain boundary and surface area compared to the single crystal NCM particles. The poly NCM particles also showed a faster DC-IR increase and a shorter lifespan than the single crystal NCM particles, indicating that the grain size has a critical influence on the battery performance and lifespan of NCM cathode materials.Our results provide insights into the design and optimization of NCM cathode materials for next-generation LIBs. By controlling the grain size and its distribution of NCM cathode materials, it is possible to enhance the battery performance and lifespan. Therefore, our study highlights the importance of understanding the microstructural features of NCM cathode materials for developing high-performance and stable LIBs.

(Digital Presentation) Anelasticity, Mechanical Spectroscopy, Internal Friction in Radiation and Structural Functionalized Nanocomposites of Multiwalled Carbon Nanotubes and Polyamide, Polyvinylchloride, Polyethylene, SiO2

Experimental Methods Ultrasound (US) impulse-phase method using computerized “KERN-4” with frequencies f┴ ≈ 0,7 MHz and f║ ≈ 1 MHz was used [1,2]. The measured velocity error was equal to ΔV/V ≈ 1,5%. Results and Discussion The influencing of ultrasonic deformation εUS was researched on mechanical properties of nanocomposite. The important value is in position of formation in the polymeric matrix of molecular structures, as multiwalled carbon nanotubes serve as the centers of crystalline phase nanocomposite origin. Amplitude-dependent internal friction (ADIF) measurement can be used as the highly sensitive method of monitoring the nanoplastic deformation eND of nanocomposites. ADIF measurement makes it possible to record the moment of dislocation segments LC separation from stoppers. Internal friction (IF) is caused by various relaxation processes that are related to nanocomposites structure defectiveness. Even rather small strain can collect up in non-ideal nanocomposites, changing their anelastic and elastic characteristics. One of the ways to purposefully change the properties of multiwalled carbon nanotubes in order to use them in nanoelectronics is to introduce impurities of other elements. It was found that as the result of the structural defect annealing IF background Q0 -1 significantly decreases during measuring of IF temperature dependences Q-1(T), which indicates the improvement of nanocomposite structure. The samples were prepared by ultrasonic dispersion using digital ultrasonic (US) bath CE-6200A with power W = 70 W at frequency f ≈ 42 kHz [1,2]. Illustration of the window for processing data of quasilongitudinal elastic waves velocity measuring V║ = 3244 ± 10 m/sec m/sec in nanocomposite polyamide (PA-6) (NH(CH2)5CO)n + 0,1% multiwalled carbon nanotubes (MCNT) by by pulse-phase US method at frequency f║ ≈ 1 MHz after electron irradiation with dose De- ≈ 10 MRad with energy Ee- ≈ 2,0 MeV is represented in Fig. 1. Fig.1. Illustration of the window for processing data of quasilongitudinal elastic waves velocity measuring V║ = 3244 m/sec in nanocomposite polyamide (PA-6) (NH(CH2)5CO)n + 0,1% MCNT by pulse-phase US method at frequency f║ ≈ 1 MHz after electron irradiation with dose De- ≈ 10 MRad.Poisson coefficient μ and elastic modulus E completely characterize the elastic properties of polymer nanocomposite. Poisson coefficient μ - elastic value of ratio of relative transversal compression e^ to relative longitudinal lengthening e║ [1]. One oscillator produces 3 waves: 1 longitudinal and 2 transversal. Debye temperature θD was determined after the formula [2], where kB - Boltzmann constant, h - Plank constant, NA - Avogadro number, A - middle gram-molecular mass, V║ - quasilongitudinal US velocity, V┴ - quasitransversal US velocity.Complex elastic modulus of nanocomposite polyamide-6 (PA-6) (NH(CH2)5CO)n + % MCNT E* is equal to the sum of elastic dynamic modulus E’ = rV║ 2 and loss modulus E” = E’d [2], where δ - logarithmic decrement of US attenuation, ρ - nanocomposite density, V║ - longitudinal US elastic waves velocity, Q-1 - internal friction, where α - US attenuation coefficient, λ - US wavelength, f - US frequency. Internal friction is equal Q-1 = δ/π. The logarithmic decrement of attenuation δ of US oscillations with amplitude A = A0e- d x is equal: δ = ln(An+1/An). Conclusions The presence of the strong interaction for nanocomposite between polyamide-6 (NH(CH2)5CO)n and multiwalled carbon nanotubes was confirmed.The increase of the nanocomposite crystallinity degree at growth of multiwalled carbon nanotubes concentration filling with the nanotubes of matrix results in the decline of content of organized phase.The phenomenon of change of Poisson coefficient m, Debye temperature θD, dynamic elastic modulus E’ = rV║ 2, dynamic shear modulus G = rV^ 2 under the influence of radiative electronic e- radiation is caused by the appearance of primary radiation defects (RD). As the result of interdefect interactions primary RD form secondary RD. Acknowledgments This work has been supported by the Ministry of Education and Science of Ukraine: Grant of the Ministry of Education and Science of Ukraine for the prospective development of the scientific direction “Mathematical sciences and natural sciences” at Taras Shevchenko National University of Kyiv. References Onanko, A.P., Kuryliuk, V.V., Onanko, Y.A. et al. Features of inelastic and elastic characteristics of Si and SiO2/Si structures. Journal of Nano- and Electronic Physics13(5), 05017(5) (2021).Onanko, A.P., Kuryliuk, V.V., Onanko, Y.A. et al. Mechanical spectroscopy and internal friction in SiO2/Si. Journal of Nano- and Electronic Physics14(6), 06029(7) (2022). Figure 1

Study of dielectric properties of polymer/air plasma treated graphene oxide nanocomposites for electronic applications

In the present study we emphasized on the dielectric properties of Ethylene Vinyl Acetate (EVA) filled with untreated and plasma-treated graphene oxide (GO). The chemical fingerprints of EVA/GO were analysed using FTIR. Decreased ID/IG ratio from 2.99 to 2.75 and 1.60 to 1.16 due to exposed plasma was confirmed by Raman spectroscopy. X-ray diffraction (XRD) disclosed the decreased degree of crystallinity. Electric properties were measured by impedance analyser, dielectric constant was increased upto 11% for untreated GO dispersion and 47% for Air treated Plasma GO dispersed EVA composites. Plasma treatment further improved the exfoliated sites of GO and induced the defects, leading to optimized dielectric properties. Improved dielectric properties of EVA/GO can provide valuable insights into the potential applications in the field of electrical connectors, film capacitors, and pseudo capacitors.

Material property characterization of 3D printed polypropylene wood plastic composites

AbstractWood flour (WF) at 10 wt.% and 20 wt.% loadings was used as a reinforcing filler to enhance the applicability of polypropylene (PP) for 3D printing. After performing printability tests of PP wood plastic composites (WPCs), the mechanical properties of both injection‐molded and 3D‐printed PP WPC specimens were explored. Test specimens were prepared from 3D printed hexagons for analyzing the mechanical properties. Adding WF to neat PP increased the storage modulus and the glass transition temperature while decreasing the degree of crystallinity and the coefficient of thermal expansion, while enhancing the printability of neat PP. The tensile strength, tensile modulus of elasticity, flexural strength, and flexural modulus of elasticity of injection‐molded neat PP improved by up to 21%, 59%, 30%, and 56%, respectively, with 20 wt.% WF. However, the impact strength of injection‐molded neat PP decreased by 85%, with 20 wt.% WF. After 3D printing, the tensile strength and tensile modulus of elasticity of printed neat PP increased by up to 84% and 60%, respectively, with 20 wt.% WF. The flexural strength and flexural modulus of elasticity of neat printed PP remained unchanged compared to those of PP filled with 20 wt.% WF, while the impact strength decreased by 87%.Highlights WF was used as a reinforcement in polypropylene designed for 3D printing A pilot‐scale, pellet‐fed 3D printer was used to print hollow hexagons, and then test specimens were fabricated from these hexagons for mechanical properties The tensile and flexural properties of 3D printed neat polypropylene improved, while the impact strength decreased after adding 20 wt.% WF to the neat PP.

Non-isothermal crystallization kinetics of biocomposites based on PLA/PHBV and spent coffee grounds

AbstractThis study deals with the modification of a predominantly amorphous poly(lactic acid) (PLA) by blending it with a semi-crystalline biopolymer, polyhydroxybutyrate-co-valerate (PHBV), which has a high crystallinity. The blends with different concentrations of PLA and PHBV were compounded with spent coffee grounds (SCGs) and processed by injection moulding. The structural, thermal and mechanical properties of the produced samples were investigated. Particular attention was paid to the effect of the presence of SCG and the concentration of PHBV in the blend on the crystallization kinetics and the heat deflection temperature (HDT). For equimolar blends, only a slight increase in HDT (about 5 °C) was observed, but the addition of PHBV suppressed the cold crystallization of PLA, which otherwise negatively affects the dimensional stability of injection moulded parts. A similar effect, but to a lesser extent, was achieved by adding SCG to the PLA matrix. Thus, it is clear that the material structures of PLA/PHBV blends and composites help to minimize additional shrinkage of the parts and increase their dimensional stability. Due to the co-continuous structure of the symmetric PLA/PHBV blends and the increase in the degree of crystallinity from 36 to 47% by annealing the produced samples, the heat deflection temperature increased from 65 up to 90 °C.

Starch Recovery Process from the Tiger Nut Horchata Processing Waste

AbstractTiger nut horchata solid residue (HSR) has high starch content (about 23%, dry basis) that can be recovered to valorise this waste, together with other valuable components, such as oil, fibres, or phenolic compounds. In this study, a chemical-free, sustainable process was proposed to obtain starch with good yield and purity. This consists of a high-speed homogenisation step with distilled water, followed by filtration and phase separation by density in the slurry to obtain a starch-rich sediment that can be isolated by decantation. Five minutes of homogenisation at 10,200 rpm allows for obtaining 14.5 g of starch powder per 100 g of dried HSR, with a purity of about 85% and WI of 94.97. Applying 1 washing cycle to the filtering residue increased the starch powder yield up to 17 g/100 dried HSR, without notable losses in starch purity, whereas centrifugation at 15,000 g for 1 h in the phase separation step highly reduced separation time, increasing starch purity up to 92%. Thus, it was possible to recover up to 70% of the starch present in the HSR. The obtained starch had similar morphological characteristics, crystallinity degree, and gelatinisation behaviour to that present in the tiger nut tubers, exhibiting similar thermal stability to that reported for other native starches. Therefore, HSR can be used as a starch source for different uses.

Enhancing Solanum lycopersicum Resilience: Bacterial Cellulose Alleviates Low Irrigation Stress and Boosts Nutrient Uptake.

The use of natural-origin biomaterials in bioengineering has led to innovative approaches in agroforestry. Bacterial cellulose (BC), sharing the same chemical formula as plant-origin cellulose (PC), exhibits significantly different biochemical properties, including a high degree of crystallinity and superior water retention capacity. Previous research showed that natural-origin glucose-based chitin enhanced plant growth in both herbaceous and non-herbaceous plants. In this study, we produced BC in the laboratory and investigated its effects on the substrate and on Solanum lycopersicum seedlings. Soil amended with BC increased root growth compared with untreated seedlings. Additionally, under limited irrigation conditions, BC increased global developmental parameters including fresh and dry weight, as well as total carbon and nitrogen content. Under non-irrigation conditions, BC contributed substantially to plant survival. RNA sequencing (Illumina®) on BC-treated seedlings revealed that BC, despite its bacterial origin, did not stress the plants, confirming its innocuous nature, and it lightly induced genes related to root development and cell division as well as inhibition of stress responses and defense. The presence of BC in the organic substrate increased soil availability of phosphorus (P), iron (Fe), and potassium (K), correlating with enhanced nutrient uptake in plants. Our results demonstrate the potential of BC for improving soil nutrient availability and plant tolerance to low irrigation, making it valuable for agricultural and forestry purposes in the context of global warming.

Degradation kinetics of PLA/hemp biocomposites: Tradeoff between nucleating action and pro-hydrolytic effect of natural fibers

Natural fibers are not only a sustainable alternative to synthetic reinforcement materials, but can also be used to produce truly sustainable biocomposites with fast degradation kinetics. Indeed, due to their hygroscopicity, lignocellulosic fibers allow water and/or degrading organisms from the external environment to penetrate inside the host matrix and trigger its hydrolysis. The latter is the rate-limiting step for the degradation of bio-polyesters, which exhibit unacceptably slow degradation kinetics at ambient temperature and humidity. However, fibers also promote crystallization of the host matrix and thus slow down its degradation kinetics. To better understand and potentially control the degradation kinetics of biocomposites, here we investigate the ability of hemp shives, a hygroscopic by-product of hemp fiber production, to accelerate the hydrolysis of poly (lactic acid) (PLA). The degradation kinetics and degree of crystallinity of PLA are monitored in water and mature compost as a function of fiber content, which was varied across the percolation threshold (Φc) to study the effect of fiber interconnectivity. Above Φc, the fibers accelerate PLA hydrolysis in water despite their nucleating effect. Conversely, in compost the shielding effect of fiber-induced crystallinity prevails, and the fibers eventually slow down the degradation kinetics of PLA.

Development and characterization of UV‐curable PCL/AESO/CNT nanocomposites for biomedical engineering

AbstractThis study investigates the development and characterization of UV‐curable Poly(ε‐caprolactone) (PCL), Acrylated Epoxidized Soybean Oil (AESO), and Carbon Nanotubes (CNT) nanocomposites for biomedical engineering applications. The PCL/AESO blends were prepared in various ratios, and CNTs were incorporated at concentrations of 0.5, 1.0, and 1.5 wt% to enhance mechanical properties. The UV‐curable formulations aimed to leverage rapid curing times, precise control over material properties, and the ability to fabricate complex structures. Results indicated that the incorporation of CNTs improved the tensile strength, modulus, and toughness of the composites. The PCL/AESO/CNT nanocomposites exhibited a tensile strength increase of 25%, a modulus improvement of 30%, and a toughness enhancement of 20% compared to pure PCL. Thermal analysis showed an increase in crystallization temperature and thermal stability, with a crystallinity degree of 63.31% and a maximum degradation temperature of 407°C for the B/C 50/50/1.5 sample. Biocompatibility assessments using L929 fibroblast cells revealed that the composites supported cell viability and proliferation over 7 days with negligible cytotoxicity. Cell attachment studies indicated favorable morphology and adherence, suggesting a conducive environment for cell growth and differentiation. Hydrolytic biodegradation studies demonstrated adjustable degradation rates, making these composites suitable for various biomedical applications requiring controlled biodegradation.

Development of PHBV electrospun fibers containing a borate bioactive glass doped with Co, Cu, and Zn for wound dressings.

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofibers embedded with borate glasses of 45B5 composition doped with Co2+, Cu2+, and Zn2 +(46.1 B₂O₃26.9-X CaO24.4 Na₂O2.6 P₂O₅, X CoO/CuO/ZnO mol % (X = 0-5)) were produced by electrospinning for wound healing applications. Prior to their addition, the glasses exhibited two broad halos typical of a vitreous borate network, which were mainly composed of ring-type metaborate structural units. The particle distribution in the PHBV nanofibers embedded with 45B5 borate bioactive glasses is present in isolated and agglomerated states, being partially coated by a polymeric layer-except for the cobalt-doped glass, which resulted in a successful encapsulation with 100% embedding efficiency. The incorporation of the glasses reduced the PHBV crystallinity degree and its decomposition temperature, as well as its mechanical properties, including Young's modulus, tensile strength, and elongation at break. The neat PHBV fibers and those containing the cobalt-doped glasses demonstrated great cytocompatibility with human keratinocytes (HaCat), as suggested by the high cell viability after 7 days of exposure. Further studies are needed to fully understand the wound healing potential of these fibers, but our results significantly contribute to the area.

Gel properties of Nicandra physalodes (Linn.) gaertn. seeds polysaccharides with tea polyphenols and its application

The novel gelling polysaccharides (NPGP) were extracted and characterized from Nicandra physalodes (Linn.) Gaertn. seeds, while properties and potential application of NPGP gels with tea polyphenols were further explored. NPGP was composed of GalA, Glc, Rha, Gal, Xyl, Ara, and Man at a molar ratio of 71.87:17.13:3.10:2.55:2.19:1.64:1.52, with molecular weight of 6.32 × 104 Da and low methoxylation degree of 45.21%. The gelling properties of NPGP gel induced by tea polyphenols showed that tea polyphenols significantly improved the structural and rheological properties of NPGP gel, due to the formation of dense network by hydrogen bonds and the increase of crystalline degree of NPGP. NPGP gels with tea polyphenols could significantly ameliorated the texture, water-holding capacity, aggregation, leading force, and moisture distribution of surimi during freeze-thaw cycles. All results suggest that NPGP gels with tea polyphenols has fine properties and show potential to be applied as natural additives in food industry.