Search Results (121)

Benzoxazine resins are gaining attention for their impressive thermal stability, low water uptake, and strong mechanical properties. In this work, two new bio-based benzoxazine monomers were developed using renewable arbutin: one combined with 3-(2-aminoethylamino) propyltrimethoxysilane (AB), and the other with furfurylamine (AF). Both were synthesized using a simple Mannich-type reaction and verified through FT-IR and ¹H-NMR spectroscopy. By blending these monomers in different ratios, copolymers with adjustable thermal, dielectric, and surface characteristics were produced. Thermal analysis showed that the materials had broad processing windows and cured effectively, while thermogravimetric testing confirmed excellent heat resistance—especially in AF-rich blends, which left behind more char. The structural changes obtained during curing process were monitored using FT-IR, and XPS verified the presence of key elements like carbon, oxygen, nitrogen, and silicon. SEM imaging revealed that AB-based materials had smoother surfaces, while AF-based ones were rougher; the copolymers fell in between. Dielectric testing showed that increasing AF content raised both permittivity and loss, and contact angle measurements confirmed that surfaces ranged from water-repellent (AB) to water-attracting (AF). Overall, these biopolymers (AB/AF copolymers) synthesized from arbutin combine environmental sustainability with customizability, making them strong candidates for use in electronics, protective coatings, and flame-resistant composite materials. Full article

Fluorescent carbon dots are nontoxic nanoparticles composed of carbon, exhibiting advantageous properties for applications in bioimaging and functional materials. We present a methodology for synthesizing fluorescent nitrogen-doped carbon dots (N-CDs) using starch, a biopolymer, and urea as the sources of nitrogen, via the microwave-assisted hydrothermal method. Furthermore, the dependence of the fluorescence spectra and fluorescence quantum yield of N-CDs on the initial concentration of urea in the reactant solution was examined, thereby providing a comprehensive understanding of the influence of nitrogen doping on the CDs. The fluorescence of N-CDs was tunable by varying the excitation wavelength. Stronger fluorescence intensity was observed for a moist phosphate salt/N-CD composite, in contrast to the weaker fluorescence exhibited by a dried one. Fluorescence lifetime measurements revealed that the change in fluorescence intensity can be attributed to the suppression of the non-radiative deactivation process. This observation highlights the critical importance of the interaction between water molecules and surface functional groups in controlling the photophysics of the excited state of N-CDs. Full article

Lignin is a complex biopolymer extracted from plant cell walls, playing a crucial role in structural integrity. As the second most abundant biopolymer after cellulose, lignin has significant industrial value in bioenergy, the chemical industry, and agriculture, gaining attention as a sustainable alternative to fossil fuels. Its composition changes during degradation, affecting its applications, making accurate analysis essential. Common lignin analysis methods include Thermogravimetric Analysis (TGA), Fourier-transform Infrared Spectroscopy (FT-IR), and Gas Chromatography–Mass Spectrometry (GC-MS). While GC-MS enables precise chemical identification, its high cost and time requirements limit frequent use in budget-constrained studies. To address this challenge, this study explores the feasibility of an artificial intelligence model that predicts the GC-MS analysis results of depolymerized lignin using data obtained from TGA and FT-IR analyses. The proposed model demonstrates potential but requires further validation across various lignin substrates for generalizability. Additionally, collaboration with organic chemists is essential to assess its practical applicability in real-world lignin and biomass research. Full article

We investigate the molecular dynamics of glycolide/lactide/caprolactone (Gly/Lac/Cap) copolymers using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), ¹H second-moment, ¹H spin-lattice relaxation time (T₁) analysis, and ¹³C solid-state NMR over a temperature range of 100–413 K. Activation energies and correlation times of the biopolymer chains were determined. At low temperatures, relaxation is governed by the anisotropic threefold reorientation of methyl (-CH₃) groups in lactide. A notable change in T₁ at ~270 K and 294 K suggests a transition in amorphous phase mobility due to translational diffusion, while a second relaxation minimum (222–312 K) is linked to CH₂ group dynamics influenced by caprolactone. The activation energy increases from 5.9 kJ/mol (methyl motion) to 22–33 kJ/mol (segmental motion) as the caprolactone content rises, enhancing the molecular mobility. Conversely, lactide restricts motion by limiting rotational freedom, thereby slowing global dynamics. DSC confirms that increasing ε-caprolactone lowers the glass transition temperature, whereas higher glycolide and lactide content raises it. The onset temperature of main-chain molecular motion varies with the composition, with greater ε-caprolactone content enhancing flexibility. These findings highlight the role of composition in tuning relaxation behavior and molecular mobility in copolymers. Full article

Green materials are emerging as sustainable alternatives in water and wastewater treatment. Due to their biodegradability, renewable origin and low toxicity characteristics, green materials are an alternative to conventional synthetic materials. Green materials include nanomaterials of natural origin, biopolymers and composites that optimize the adsorption and removal of contaminants. The applications of cellulose nanofibers, alginates, chitosan and lignin stand out, as well as functionalized hydrogels and aerogels for the removal of heavy metals, dyes and organic contaminants. The analysis of the mechanisms and processes of contaminant removal and modeling and optimization techniques are included as key emerging tools for the design and optimization of these materials, allowing one to predict properties, simulate interactions and customize solutions. Despite the sustainability benefits of green materials, they face technical and economic challenges, such as scalability, synthesis costs and experimental validation. This work concluded that green materials, combined with modeling and optimization tools, are essential to move towards more sustainable, efficient and environmentally friendly water treatment technologies, aligned with global objectives of sustainable development and climate change mitigation. Full article

Composite biopolymer hydrogel as food packaging material, apart from being environmentally favorable, faces high standards set upon food packaging materials. The feature that favors biopolymer film application is their low gas permeability under room conditions and lower relative humidity conditions. However, most biopolymer-based materials show high moisture sensitiveness and limited water vapor permeability, which limits their application for food packaging. In this paper, a new packaging material derived from an edible oil industry byproduct (pumpkin oil cake) coated with a thin layer of paraffin wax was obtained. Compared to the film without wax coating, the new material showed reduced water sensitivity and significantly reduced water vapor transmission rate (56.98 ± 7.42 g/m² 24 h). The new material was tested for packing dry apricot slices under a modified atmosphere (100% N₂). Gas composition in PuOC/wax pouches’ headspace was minimally changed during 105 days of storage. The low moisture content (6.76–10.60%) of dried apricot slices was preserved throughout the storage period (p > 0.05), as well as high rehydration power (65–75%). Changes in sensorial properties during storage were minimal. Total phenol content was minimally reduced during storage, followed by antioxidant activity (FRAP and ABTS trial). The microbial profile of dried apricot slices showed that a safe product was obtained throughout the storage. Considering the results, the functionality of new material for packing dry apricots under a modified atmosphere was proven. Full article

The influence of the addition of ground buckwheat hulls on the properties of biocomposite on the basis of 3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV) is presented here. The changes in the material after repeated reprocessing—up to five recycling cycles—are written in the paper. Analysis of the shrinkage, water adsorption, selected mechanical properties, tensile impact strength, hardness and the microstructure of the surface layer was performed. The results show that the application of the buckwheat hulls into the biopolymer decreases the material shrinkage. It improves the material dimensional stability, as well as increases the water adsorption in the wake of the hydrophobic properties of the filler. The addition of the natural filler also leads to an increase in composite stiffness. The decrease in the tensile impact strength and the elongation at break is also noted. The reprocessing of the biocomposite initially led to a decrease in its mechanical properties, but the results stabilized after further processing cycles. This indicates the improvement of the microstructure homogeneity. The microscopic analysis shows that buckwheat hull particles were better embedded in the matrix after recycling. The increase in hardness was also noted. The PHBV–ground buckwheat hull biocomposite is characterized by stable mechanical properties and by recycling resistance, which makes it a promising material in terms of the sustainable development. Full article

Wastewater treatment plants (WWTPs) offer the possibility of recovering valuable substances produced by microorganisms, such as extracellular polymeric substances (EPSs). This study aimed to investigate the generation and properties of biopolymers and microbial communities of activated sludge from a large, full-scale WWTP. EPS composition in the activated sludge changed mostly during the transition period from winter to spring. Higher temperatures favored higher protein (PN) concentrations and a higher PN/PSs (polysaccharides) ratio in tightly-bound EPS, stimulating bacterial aggregation. In the sludge, filamentous Microthrix sp. were abundant (~6%) but the settling properties of the sludge improved with increasing PN content in the bound EPS fraction. The content of alginate (ALE)-like polymers averaged 55–60 mg/g Mixed Liquor Suspended Solids, and ALE content in sludge and characteristics were stable during the year. The abundance of Nitrospira sp. and the marine group NS9 in activated sludge correlated with the ALE content in the biomass, pointing to the importance of biopolymer production for nitrogen-transforming microorganisms. The most common EPS-producer was, Candidatus Competibacter (3–4%). The abundance of the Roseiflexaceae family significantly increased in summer, as did the abundance of Trichoccus sp. and Flavobacterium sp. in winter. The study shows that seasonal temperature fluctuations do not significantly affect the production of polymers, especially alginate, which favors commercial ALE recovery. The non-uniform composition of ALE-like polymers shows the possibility of their use in areas that do not require a specific polymer composition, e.g., as environmentally friendly coating materials or sorbents. The study contributes to biopolymer recovery and valorization of activated sludge. Full article

Natural and synthetic biopolymers are gaining popularity in the development of inhaled drug formulations. Their highly tunable properties and ability to sustain drug release allow for the incorporation of attributes not achieved in dry powder inhaler formulations composed only of micronized drugs, standard excipients, and/or carriers. There are multiple physiological barriers to the penetration of inhaled drugs to the epithelial surface, such as the periciliary layer mucus mesh, pulmonary macrophages, and inflammation and mucus compositional changes resulting from respiratory diseases. Biopolymers may facilitate transport to the epithelial surface despite such barriers. A variety of categories of biopolymers have been assessed for their potential in inhaled drug formulations throughout the research literature, ranging from natural biopolymers (e.g., chitosan, alginate, hyaluronic acid) to those synthesized in a laboratory setting (e.g., polycaprolactone, poly(lactic-co-glycolic acid)) with varying structures and compositions. To date, no biopolymers have been approved as a commercial dry powder inhaler product. However, advances may be possible in the treatment of respiratory diseases and infections upon further investigation and evaluation. Herein, this review will provide a thorough foundation of reported research utilizing biopolymers in dry powder inhaler formulations. Furthermore, insight and considerations for the future development of dry powder formulations will be proposed. Full article

Collapsible loess is characterized by its unique soil-forming environment, mineral composition, and microstructure, resulting in poor engineering properties such as high water sensitivity, high collapsibility, high compressibility, and low strength. To improve the poor engineering properties of collapsible loess, we selected a suitable eco-friendly material—guar gum (GG)—for its improvement and reinforcement, and investigated the improvement effect of different GG dosages (0.5~1.5%) and curing ages (0~28 days) on collapsible loess. The mechanical properties of soil samples were determined by direct shear tests, unconfined compressive strength tests, and splitting tests. The water stability of soil samples was evaluated by both cube and sphere crumb tests. SEM and EDS analyses were also conducted to determine the microstructural and mineral changes in soil. The results indicate that the incorporation of GG is beneficial to inhibit the collapsibility of the soil and improves the water stability and strength of the soil. The collapsibility coefficient of loess is reduced to below 0.015 when 0.75% and above of GG is admixed, which is considered a complete loss of its collapsibility. When the GG dosage increases from 0% to 1.25%, the compressive strength and tensile strength of the soil samples increase by 43.5% and 34.9%, respectively. However, by further increasing the GG dosage to 1.5%, the compressive strength and tensile strength decrease by 3.8% and 6% compared to those with 1.25% GG. This indicates that the strength of the specimens shows an increasing trend and then a decreasing trend with the increase in GG dosage, and 1.25% GG was found to be the best modified dosage. Microstructural and mineral analyses indicate that the addition of GG does not change the mineral composition of loess, but, rather, it significantly promotes the agglomeration and bonding of soil particles through cross-linking with Ca²⁺ ions in the soil to form a biopolymer network, thus achieving a reliable reinforcement effect. Compared with the existing traditional stabilizers, GG is a sustainable and eco-friendly modified material with a higher low-carbon value. Therefore, it is very necessary to mix GG into collapsible loess to eliminate some of the poor engineering properties of loess to meet engineering needs. This study can provide test support for the application and promotion of GG-modified loess in water agriculture and road engineering. Full article

Biopolymer blends of polylactic acid (PLA) and polybutylene adipate-co-terephthalate (PBAT) are extruded into flexible monolayer films. These blends are excellent candidates for the realization of environmentally friendly packaging applications. A necessary pre-requisite for that are appropriate tribological properties under mechanical contact. Reasonable wear resistance allows good protection of packed goods, and low friction forces reduce difficulties in stacking. In this research, mechanical embossment under high loads at room temperature was used for the modification of polymer surfaces to exhibit a significant friction reduction under dry conditions. The results particularly show a systematic decrease in the coefficient of friction for biopolymer blends containing 30 wt% and 40 wt% PBAT. FTIR was used to analyze the change in surface composition after mechanical embossing. A sophisticated FTIR calibration method revealed that the blend with 30 wt% PBAT shows a modified distribution of PBAT and PLA at the surface due to mechanical embossment. This leads to a controlled and long-lasting modification of the surface properties without a substantial change in the chemical composition of the polymer in bulk. Without the use of additional coatings, biodegradable packaging foils with improved characteristics are accessible. Full article

The application of biopolymers for sand stabilization has recently gained attention due to their natural composition, which makes them both environmentally friendly and of reasonable cost. Measuring the soil–water retention curve (SWRC) of biopolymers-treated sand is essential for the design, modeling, and interpretation of the unsaturated behavior of these materials. Unsaturated shear strength, unsaturated flow, and associated retention capacity are well addressed and evaluated using SWRC. Therefore, this study examined the possible effects of biopolymers—sodium alginate (SA), guar gum (GG), and pectin (P) on the SWRC and retention capacity for stabilized sand. Apart from natural sand, three different concentrations were investigated for each biopolymer. The SWRCs were measured over the entire practical range of suction using a combination of three techniques: hanging column for low suction measurement, axis translation techniques for moderate suction measurement, and vapor equilibrium technique for high suction measurement. The results indicate significant changes in SWRC, and a new series of micropores was developed, this, in turn, extends the desaturation zone of treated sand from a low suction range (i.e., 30 kPa) to moderate to high suction levels (i.e., 10,000 kPa). The saturated water content (w_s) was slightly reduced, air entry values (AEVs), and residual suction (s_r) significantly increased and multiplied up to 200 and 75 times respectively. The retention capacity increased, exhibiting a dependency between the biopolymer type and suction range. The results are of great significance for both practitioner engineers and researchers in predicting the unsaturated soil functions of treated sand. Full article

The development of biopolymer-based films represents a promising direction in the packaging industry that responds to stringent needs for sustainability, reducing the ecological impact. Traditional fossil-derived polymers present major concerns because of their long decomposition time and their significant contribution to the pollution of the environment. On the contrary, biopolymers such as chitosan, PVA, and PLA offer viable alternatives. This study aimed to obtain an innovative pH indicator for smart packaging using a synthetic non-toxic anthocyanin analogue dye incorporated in bio-based films to indicate meat freshness and quality. The pH-responsive color-changing properties of the dye make it suitable for developing intelligent films to monitor food freshness. The obtained polymeric films were characterized by FT-IR and UV–VIS spectroscopy, and their thermal properties were assessed using thermogravimetric methods. Moisture content, swelling capacity, and water solubility of the polymeric films were also evaluated. The sensitivity of the biopolymer–flavylium composite films to pH variations was studied in the pH range of 2 to 12 and noticeable color variations were observed, allowing the monitoring of the meat’s quality damage through pH changes. The pH-responsive films were applied directly on the surface or in the proximity of pork and chicken meat samples, to evaluate their colorimetric response to fresh and spoilt meat. This study can be the starting point for creating more durable packaging solutions leading to a circular economy. Full article

There is a significant trend towards the integration of natural substances with bio-polymers for fully bio-based functional composites. Polylactic acid is regarded as a promising biodegradable polymer for replacing synthetic polymers. Differing from the case of natural fiber, the incompatibility of polylactic acid with bio-based molecules prevents it from being used to fabricate high-quality sustainable composites. This work presents a simultaneous ultraviolet shielding and antibacterial finishing process of polylactic acid combined with bioactive baicalin and an eco-friendly ester, which is highlighted for (a) the lack of synthetic chemicals involved in such process, (b) adsorption enhancement achieved at a mild temperature, and (c) marginal color change on treated polylactic acid. A response surface methodology was adopted to analyze the impacts of various factors on the baicalin quantity in polylactic acid, and to optimize the treatment condition. The uptake ratio of baicalin in polylactic acid was drastically promoted from 8.5 mg/g to 21.1 mg/g using methyl cinnamate. The response surface methodology based on a central composite design experiment indicated that the usage of baicalin was the most significant factor followed by methyl cinnamate and temperature. After optimization, a very faint color depth of 1.2 was apparent, but UPF 50+ and 92% bacterial reduction could be achieved. In all, the success in strengthening of the functionalities of polylactic acid extends the applications of polylactic acid products. Full article

The investigation of novel, natural polymers has gained considerably more exposure for their desirable, often specific, functional properties. Multiple researchers have explored these biopolymers to determine their potential to address many food processing, packaging and environmental concerns. Mucilage from the cactus pear (Opuntia ficus-indica) is one such biopolymer that has been identified as possessing a functional potential that can be used in an attempt to enhance food properties and reduce the usage of non-biodegradable, petroleum-based packaging in the food industry. However, variations in the structural composition of mucilage and the different extraction methods that have been reported by researchers have considerably impacted mucilage’s functional potential. Although not comparable, these factors have been investigated, with a specific focus on mucilage applications. The natural ability of mucilage to bind water, alter the rheology of a food system and develop biofilms are considered the major applications of mucilage’s functional properties. Due to the variations that have been reported in mucilage’s chemical composition, specifically concerning the proportions of uronic acids, mucilage’s rheological and biofilm properties are influenced differently by changes in pH and a cross-linker. Exploring the factors influencing mucilage’s chemical composition, while co-currently discussing mucilage functional applications, will prove valuable when evaluating mucilage’s potential to be considered for future commercial applications. This review article, therefore, discusses and highlights the key factors responsible for mucilage’s specific functional potential, while exploring important potential food processing and packaging applications. Full article