The effect of MgO nanoparticle on PVA/PEG-based membranes for potential application in wound healing.

The interest in wound dressings increased ten years ago. Wound care practitioners can now use interactive/bioactive dressings and tissue-engineered skin substitutes. Several bandages can heal burns, but none can treat all chronic wounds. This study formulates a composite material from 70% polyvinyl alcohol (PVA) and 30% polyethylene glycol (PEG) with 0.2, 0.4, and 0.6 wt% magnesium oxide nanoparticles. This study aims to create a biodegradable wound dressing. A Fourier Transform Infrared (FTIR) study shows that PVA, PEG, and MgO create hydrogen bonding interactions. Hydrophilic characteristics are shown by the polymeric blend's 56.289° contact angle. MgO also lowers the contact angle, making the film more hydrophilic. Hydrophilicity improves film biocompatibility, live cell adhesion, wound healing, and wound dressing degradability. Differential Scanning Calorimeter (DSC) findings suggest the PVA/PEG combination melted at 53.16 °C. However, adding different weight fractions of MgO nanoparticles increased the nanocomposite's melting temperature (Tm). These nanoparticles improve the film's thermal stability, increasing Tm. In addition, MgO nanoparticles in the polymer blend increased tensile strength and elastic modulus. This is due to the blend's strong adherence to the reinforcing phase and MgO nanoparticles' ceramic material which has a great mechanical strength. The combination of 70% PVA + 30% PEG exhibited good antibacterial spatially at 0.2% MgO, according to antibacterial test results.

Pyrogallic acid-compatibilized polylactic acid/thermoplastic starch blend produced via one-step twin-screw extrusion.

In this study, a one-step extrusion method is proposed to prepare blended polylactic acid (PLA)/thermoplastic starch (TPS) using a novel plant-derived compatibilizer, pyrogallic acid (PGA), to enhance the PLA/TPS compatibility. The effects of PGA on the mechanical behavior, fractured cross-section morphology, thermal and dynamic mechanical performance, and water resistance of PLA/TPS blends were systematically studied. Results demonstrate that the addition of PGA effectively improves the compatibility between TPS and PLA, resulting in enhanced tensile strength, crystallinity, elongation at break, thermal stability, and hydrophobicity of the blends. Specifically, incorporating 1.5 phr of PGA into the blend system yields the highest values for tensile strength (23.38 MPa) and elongation at break (16.96 %), which are 24.7 % and 233.2 %, respectively, higher than those observed for pure PLA/TPS blends. Furthermore, other properties exhibit obvious improvements upon incorporation of PGA into the blends. This approach provides a promising strategy for enhancing the performance of PLA/TPS blends and expanding their applications in food packaging, agricultural film, etc.

Electrospun Silicon Dioxide/poly(vinylidene fluoride) Nanofibrous Membrane Comprising a Skin Multicore-Shell Nanostructure as a New High-Heat-Resistant Separator for Lithium-Ion Polymer Batteries.

Porous silicon dioxide (SiO2)/poly(vinylidene fluoride) (PVdF), SiO2/PVdF, and fibrous composite membranes were prepared by electrospinning a blend solution of a SiO2 sol-gel/PVdF. The nanofibers of the SiO2/PVdF (3/7 wt. ratio) blend comprised skin and nanofibrillar structures which were obtained from the SiO2 component. The thickness of the SiO2 skin layer comprising a thin skin layer could be readily tuned depending on the weight proportions of SiO2 and PVdF. The composite membrane exhibited a low thermal shrinkage of ~3% for 2 h at 200 °C. In the prototype cell comprising the composite membrane, the alternating current impedance increased rapidly at ~225 °C, and the open-circuit voltage steeply decreased at ~170 °C, almost becoming 0 V at ~180 °C. After being exposed at temperatures of >270 °C, its three-dimensional network structure was maintained without the closure of the pore structure by a melt-down of the membrane.

Improving Miscibility of Polymer Donor and Polymer Acceptor by Reducing Chain Entanglement for Realizing 18.64% Efficiency All Polymer Solar Cells.

All-polymer solar cells have experienced rapid development in recent years by the emergence of polymerized small molecular acceptors (PSMAs). However, the strong chain entanglements of polymer donors (PDs) and polymer acceptors (PAs) decrease the miscibility of the resulting polymer mixtures, making it challenging to optimize the blend morphology. Herein, we designed three PAs, namely PBTPICm-BDD, PBTPICγ-BDD and PBTPICF-BDD, by smartly using a BDD unit as the polymerized unit to copolymerize with different Y-typed non-fullerene small molecular acceptors (NF-SMAs), thus achieving a certain degree of distortion and giving the polymer system enough internal space to reduce the entanglements of the polymer chains. Such effects increase the chances of the PD being interspersed into the acceptor material, which improve the solubility between the PD and PA. The PBTPICγ-BDD and PBTPICF-BDD displayed better miscibility with PBQx-TCl, leading to a well optimized morphology. As a result, high power conversion efficiencies (PCEs) of 17.50% and 17.17% were achieved for PBQx-TCl:PBTPICγ-BDD and PBQx-TCl:PBTPICF-BDD devices, respectively. With the addition of PYF-T-o as the third component into PBQx-TCl:PBTPICγ-BDD blend to further extend the absorption spectral coverage and finely tune microstructures of the blend morphology, a remarkable PCE of 18.64% was realized finally.

Dielectric Properties of PEEK/PEI Blends as Substrate Material in High-Frequency Circuit Board Applications.

Substrate materials for printed circuit boards must meet ever-increasing requirements to keep up with electronics technology development. Especially in the field of high-frequency applications such as radar and cellular broadcasting, low permittivity and the dielectric loss factor are key material parameters. In this work, the dielectric properties of a high-temperature, thermoplastic PEEK/PEI blend system are investigated at frequencies of 5 and 10 GHz under dried and ambient conditions. This material blend, modified with a suitable filler system, is capable of being used in the laser direct structuring (LDS) process. It is revealed that the degree of crystallinity of neat PEEK has a notable influence on the dielectric properties, as well as the PEEK phase structure in the blend system developed through annealing. This phenomenon can in turn be exploited to minimize permittivity values at 30 to 40 wt.-% PEI in the blend, even taking into account the water uptake present in thermoplastics. The dielectric loss follows a linear mixing rule over the blend range, which proved to be true also for PEEK/PEI LDS compounds.

Specific cultivation-independent enumeration of viable cells in probiotic products using a combination of fluorescence in situ hybridization and flow cytometry.

This study introduces an optimized integration of flow cytometry and fluorescence in situ hybridization (Flow-FISH) as an approach for the specific enumeration of gram-positive bacteria in probiotic products, overcoming the limitations of conventional methods. The enhanced Flow-FISH technique synergizes the rapid and automated capabilities of flow cytometry with the high specificity of FISH, facilitating the differentiation of viable cells at the species level within probiotic blends. By analyzing lyophilized samples of Lacticaseibacillus rhamnosus, Lactiplantibacillus plantarum, and Bifidobacterium animalis subsp. lactis, and a commercial product, the study highlights the optimized Flow-FISH protocol's advantages, including reduced hybridization times to 1.5 h and elimination of centrifugation steps. Comparative evaluations with the widely accepted enumeration methods plate count and Live/Dead (L/D) staining were conducted. The study revealed that Flow-FISH produces higher viable cell counts than plate count, thereby challenging the traditional "gold standard" by highlighting its predisposition to underestimate actual viable cell numbers. Against L/D staining, Flow-FISH achieved comparable results, which, despite the different foundational premises of each technique, confirms the accuracy and reliability of our method. In conclusion, the optimized Flow-FISH protocol represents a significant leap forward in probiotic research and quality control. This method provides a rapid, robust, and highly specific alternative for the enumeration of probiotic bacteria, surpassing traditional methodologies. Its ability to enable a more detailed and reliable analysis of probiotic products paves the way for precise quality control and research insights, underscoring its potential to improve the field significantly.

Solution-processed poly(vinylidene difluoride)/cellulose acetate/Li1+xAlxTi2-x(PO4)3 composite solid electrolyte for improving electrochemical performance of solid-state lithium-ion batteries at room temperature.

To enhance energy density and secure the safety of lithium-ion batteries, developing solid-state electrolytes is a promising strategy. In this study, a composite solid-state electrolyte (CSE) composed of poly(vinylidene difluoride) (PVDF)/cellulose acetate (CA) matrix, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt, and Li1.3Al0.3Ti1.7(PO4)3 (LATP) fillers is developed via a facile solution-casting method. The PVDF/CA ratio, LiTFSI, and LATP fractions affect the crystallinity, structural porosity, and thermal and electrochemical stability of the PVDF/CA/LATP CSE. The optimized CSE (4P1C-40LT/20F) presents a high ionic conductivity of 4.9 × 10-4 S cm-1 and a wide electrochemical window up to 5.0 V vs. Li/Li+. A lithium iron phosphate-based cell containing the CSE delivers a high discharge capacity of over 160 mAh g-1 at 25 °C, outperforming its counterpart containing PVDF/CA polymer electrolyte. It also exhibits satisfactory cycling stability at 1C with approximately 90 % capacity retention at the 200th cycle. Additionally, its rate performance is promising, demonstrating a capacity retention of approximately 80 % under varied rates (2C/0.1C). The increased amorphous region, Li+ transportation pathways, and Li+ concentration of the 4P1C-40LT/20F CSE membrane facilitate Li+ migration within the CSE, thus improving the battery performance.

Peptide direct growth on poly(acrylic acid)/poly(vinyl alcohol) electrospun fibers coated with branched poly(ethylenimine): A solid-phase approach for scaffolds biofunctionalization.

Due to their resemblance to the fibrillar structure of the extracellular matrix, electrospun nanofibrous meshes are currently used as porous and mechanically stable scaffolds for cell culture. In this study, we propose an innovative methodology for growing peptide sequences directly onto the surface of electrospun nanofibers. To achieve this, electrospun fibers were produced from a poly(acrylic acid)/poly(vinyl alcohol) blend that was thermally crosslinked and subjected to a covalent coating of branched poly(ethylenimine). The exposed amino functionalities on the fiber surface were then used for the direct solid-phase synthesis of the RGD peptide sequence. In contrast to established strategies, mainly involving the grafting of pre-synthesized peptides onto the polymer chains before electrospinning or onto the nanofibers surface, this method allows for the concurrent synthesis and anchoring of peptides to the substrate, with potential applications in combinatorial chemistry. The incorporation of this integrin-binding motive significantly enhanced the nanofibers' ability to capture human cervical carcinoma (HeLa) cells, selected as a proof of concept to assess the functionalities of the developed material.

Enhanced production of yellow fever virus through tailored culture media optimization.

In the present study, an initial screening was conducted using 12 types of cell culture media, and four media with the best performance were selected for further study. The optimization of four media blend for YFV production was evaluated using an Augmented simplex centroid mixture design. Among all the different models that were investigated, the quadratic model was found to be the most appropriate model for exploring mixture design. It was found that M10 exhibited the greatest impact on YFV production, followed by M9, M4, and M1. The utilization of M1 and M4 media individually yielded higher compared to their blends with other media. The YFV titers were reduced when M1 media was combined with other media. The utilization of M9 and M10 media in combination resulted a higher viral yield compared to their respective concentrations. The optimal ratio for achieving a higher titer of YFV from primary CEFs was found to be approximately 38:62, with M9 and M10 being the most favorable media blend. The use of a media mixture led to a significant increase of virus titer up to 2.6 × 108 PFU/ml or 2 log titer yield, which is equivalent to 1.92 × 105 doses, without any changes to growth conditions or other process factors. This study concluded that the utilization of a mixture design could be efficiently employed to choose the optimal combination of media blends for enhanced viral production from cell culture.

Nanostructured Molecular Packing of Polymer Films Formed on Water Surfaces.

In this study, we examined the nanostructured molecular packing and orientations of poly[[N,N'-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5'-(2,2'-bithiophene)] (P(NDI2OD-T2)) films formed on water for the application of nanotechnology-based organic electronic devices. First, the nanoscale molecule-substrate interaction between the polymer and water was modulated by controlling the alkyl side chain length in NDI-based copolymers. Increasing alkyl side chain lengths induced a nanomorphological transition from face-on to edge-on orientation, confirmed by molecular dynamics simulations revealing nanostructural behavior. Second, the nanoscale intermolecular interactions of P(NDI2OD-T2) were controlled by varying the volume ratio of the high-boiling-point additive solvent in the binary solvent blends. As the additive solvent ratio increased, the nanostructured molecular orientation of the P(NDI2OD-T2) films on water changed remarkably from edge-on to bimodal with more face-on crystallites, thereby affecting charge transport. Our finding provides essential insights for precise nanoscale morphological control on water substrates, enabling the formation of high-performance polymer films for organic electronic devices.

In-situ self-reinforcement of amorphous polylactide (PLA) through induced crystallites network and its highly ductile and toughened PLA/poly(butylene adipate-co-terephthalate) (PBAT) blends.

Crystallites of a semicrystalline polylactide (cPLA) were induced in an amorphous PLA (aPLA) and its blends with poly(butylene adipate-co-terephthalate) (PBAT) to achieve in-situ self-reinforced PLA based structures. The approach involved the melt blending of cPLA as a minor phase with aPLA and its blends with PBAT at processing temperatures below the crystal melting peak of cPLA. An injection molding (IM) process was first adopted to obtain self-reinforced PLA (SR-PLA) structures at aPLA/cPLA weight ratios of 100/0, 95/5, 90/10, 85/15, and 80/20. IM barrel and mold temperatures revealed crucial impacts on preserving the cPLA crystallites and thereby enhancing the final mechanical performance of SR-PLA (i.e., aPLA/cPLA) samples. SR-PLA samples at various aPLA/cPLA weight ratios of 100/0, 90/10, 80/20, and 70/30 were then melt blended with PBAT to produce SR-PLA/PBAT at a given ratio of 85/15. These blends were first prepared in an internal melt mixer (MM) to evaluate the rheological properties. The rheological analysis confirmed the significance of cPLA reinforcing efficiency within SR-PLA and its corresponding blends with PBAT. Similar SR-PLA/PBAT blends were also prepared using the IM process to explore their thermal and mechanical characteristics. The effect of cPLA concentrations in blends was distinctive, leading to significant enhancements in stain at break and toughness values. This was due to the increased crystallite network within the matrix, further refining PBAT droplets. Morphological analysis of the melt-processed blends through MM and IM also revealed that the PBAT droplets were further refined when the IM process was applied. The induced shear during the molding could have further elongated the cPLA crystallites towards a fiberlike structure, which could additionally cause the matrix viscosity to increase and refine the PBAT droplets.

Effect of mPEG-PLGA on Drug Crystallinity and Release of Long-Acting Injection Microspheres: In Vitro and In Vivo Perspectives.

PURPOSE: Traditional progesterone (PRG) injections require long-term administration, leading to poor patient compliance. The emergence of long-acting injectable microspheres extends the release period to several days or even months. However, these microspheres often face challenges such as burst release and incomplete drug release. This study aims to regulate drug release by altering the crystallinity of the drug during the release process from the microspheres. METHODS: This research incorporates methoxy poly(ethylene glycol)-b-poly(lactide-co-glycolide) (mPEG-PLGA) into poly(lactide-co-glycolide) (PLGA) microspheres to enhance their hydrophilicity, thus regulating the release rate and drug morphology during release. This modification aims to address the issues of burst and incomplete release in traditional PLGA microspheres. PRG was used as the model drug. PRG/mPEG-PLGA/PLGA microspheres (PmPPMs) were prepared via an emulsification-solvent evaporation method. Scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), and differential scanning calorimetry (DSC) were employed to investigate the presence of PRG in PmPPMs and its physical state changes during release. RESULTS: The addition of mPEG-PLGA altered the crystallinity of the drug within the microspheres at different release stages. The crystallinity correlated positively with the amount of mPEG-PLGA incorporated; the greater the amount, the faster the drug release from the formulation. The bioavailability and muscular irritation of the long-acting injectable were assessed through pharmacokinetic and muscle irritation studies in Sprague-Dawley (SD) rats. The results indicated that PmPPMs containing mPEG-PLGA achieved low burst release and sustained release over 7 days, with minimal irritation and self-healing within this period. PmPPMs with 5% mPEG-PLGA showed a relative bioavailability (Frel) of 146.88%. IN CONCLUSION: In summary, adding an appropriate amount of mPEG to PLGA microspheres can alter the drug release process and enhance bioavailability.

A Novel Method to Characterize the Damping Capacity of EPDM/CIIR Blends Using Vibrating Rubber Balls.

An experimental device fixed with a laser displacement sensor was assembled to investigate the rebound behaviors and damping mechanism of rubber balls prepared with ethylene-propylene-diene monomer (EPDM)/chlorinated butyl rubber (CIIR) blends. The result showed that a prediction model was proposed to characterize the damping capacity by using the rebound height of the rubber balls. The lower rebound height corresponded to better damping capacity. A modified equation relating to the rebound height has been obtained from the theoretical derivation on the basis of the dynamic mechanical analysis, showing that the rebound height was affected by the deformation frequency, the external excitation, and the nature of rubber blends. Furthermore, the energy dissipation rate (EDR), defined by the ratio of the height loss to the rebound time, was proposed to further characterize the damping capacity. The EDR value was shown to be highest for the pure CIIR and lowest for the pure EPDM, exhibiting a decreasing trend with the increase in EPDM content in the rubber blends. It can be expected that the damping capacity of the EPDM/CIIR blends decreases with the decrease in external excitation, the conclusion of which plays a key role in the formulation design of viscoelastic damping rubber materials.

Polylactic Acid/Saqqez Gum Blends for Chewing Gum Applications: Impact of Plasticizers on Thermo-Mechanical and Morphological Properties.

This study investigated a blend of poly (lactic acid) (PLA) and Saqqez gum, with a weight ratio of 70:30, respectively, along with two plasticizers, acetyl tributyl citrate (ATBC) and polyethylene glycol (PEG), at three different concentrations (14%, 16% and 18% by weight of the PLA). The blend was analyzed using differential scanning calorimetry (DSC), scanning electron microscopy (SEM), tensile tests, water-absorption behavior (coefficients of water absorption, sorption, diffusion and permeability of the samples during 240 h) and chemical resistance (exposure to 1 mol/L HCl and 1 mol/L NaOH for 240 h). The desired elastomer blend was then used to prepare natural chewing gum, which was subsequently subjected to texture profile analyzer (TPA) tests and sensory evaluation. The results showed that the addition of both plasticizers increased the tensile properties of the blend. Compared to neat PLA, all the blends exhibited an increase in elongation at break and a decrease in yield strength, with the maximum elongation at break (130.6%) and the minimum yield strength (12.2 MPa) observed in the blend containing 16% ATBC. Additionally, all the thermal attributes studied, including Tg, Tc and Tm, were lower than those of neat PLA, and the Tg values deviated from the values predicted via Fox's equation. SEM images of the blends confirmed that plasticization improved the homogeneity and distribution of the components in the blend structure. PEG 18% and ATBC 16% exhibit the highest and lowest water-absorption behavior, respectively. Regarding chemical resistance, all blends showed weight gain when exposed to HCl, while no weight loss was observed for resistance to NaOH. The chewing gum sample obtained similar values for the mentioned tests compared to the commercial control sample. Overall, the results indicate that plasticization enhances the structure and performance of the PLA/Saqqez gum blend and further investigation is warranted.

Exploring effect of uniform dry ball-milling duration on pasting and rheological properties of pink potato and maize starch mixtures.

This study examined the potential effect of ball milling on maize starch (MS), pink potato starch (PPS), and their blends in various ratios (90:10, 80:20, and 70:30) on the pasting and rheological properties. Ball-milling led to changes in the particle size, ranging from 652.9 to 6488 nm, and a decrease in relative crystallinity (RC), as confirmed by XRD. Ball-milling increased amylose concentration in blend with the ratio of 90:10 up to 32.53 %, indicating structural alterations and molecular interactions. FESEM analysis confirms significant changes in the surface and particle sizes and starch gels with honeycomb structures. FTIR and Raman spectroscopy revealed a decrease in the intensity of the 1044 cm-1 and 480 cm-1 bands, respectively, signifying structural changes. Pasting parameters like peak viscosity and gelatinization behavior varied with PPS incorporation. The 80:20 blend had the highest viscosity, demonstrating PPS's capacity for high-viscosity starch paste. Rheological measurements of starch blends exhibited shear-thinning behavior, whereas the viscoelastic properties of the blends are influenced by particle size and the ratio of pink potato starch. Ball-milling treatment affects the granules and causes molecular-level interactions between the particles. This results in unique rheological properties of the starch blends, making them suitable for various applications.

Development of active film based on collagen and hydroxypropyl methylcellulose incorporating apple polyphenol for food packaging.

Collagen (COL)-hydroxypropyl methylcellulose (HPMC) blended films with apple polyphenol (AP) as cross-linking agent and antioxidant compound were developed to produce biodegradable active packaging film. The effects of AP content on the rheological behavior of the blended solution, the structure, physicochemical and functional properties of the blended film were systematically investigated. The incorporation of AP increased the viscosity and reduced the fluidity of COL-HPMC solution. The results of rheological tests and FTIR analysis manifested the formation of hydrogen bonding interactions between collagen, HPMC and AP, which made the structures of COL-HP-AP films more compact. The mechanical strength, UV-blocking ability, water-resistance performance and thermostability were gradually enhanced as increasing AP content. DPPH free radical scavenging experiment showed that a small amount of AP could efficiently improve the antioxidant activity of COL-HP film, and with increasing AP content to 5 wt%, the scavenging rate was as high as 94.23 %. Active film containing 5 wt% AP showed obvious antibacterial effect on E. coli and S. aureus, and it could effectively prevent the oxidation of vitamin C and reduce the accumulation of MDA on green pepper during the storage. COL-HP-AP films have great potential in food packaging field for extending the shelf life of food.

The Response Surface Methodology for Assessment of HLB Values of Mixtures of Non-Ionic Surfactants Using Parameters from Their π-A Isotherms.

The aim of the work was to determine important parameters of the course of π-A isotherms, which can determine the HLB (hydrophilic-lipophilic balance) value of surfactant mixtures with selected structural features, such as a straight or branched hydrocarbon chain and a double bond, using RSM (response surface methodology) computational methods. Mixtures of surfactants derived from fatty acids and sorbitan with specific HLB values were evaluated by Langmuir trough. The resulting elasticity modules (ELM) and molecules surfaces (SAM) were evaluated via response surface methodology and respective equations were calculated. The π-A isotherm determined in a Langmuir trough and the ELM and SAM parameters determined on the basis of this isotherm may be useful for determining the HLB of a fixed surfactant mixture. The RSM method used, in which ELM and SAM were assumed as two independent variables, can be a useful technique for tracking the influence of individual molecular characteristics on the hydrophilic-lipophilic properties of mixtures of surfactant compounds. Changes in HLB as a dependent variable can be described as a function of ELM and SAM.

Small diameter vascular grafts: progress on electrospinning matrix/stem cell blending approach.

The exploration of the next-generation small diameter vascular grafts (SDVGs) will never stop until they possess high biocompatibility and patency comparable to autologous native blood vessels. Integrating biocompatible electrospinning (ES) matrices with highly bioactive stem cells (SCs) provides a rational and promising solution. ES is a simple, fast, flexible and universal technology to prepare extracellular matrix-like fibrous scaffolds in large scale, while SCs are valuable, multifunctional and favorable seed cells with special characteristics for the emerging field of cell therapy and regenerative medicine. Both ES matrices and SCs are advanced resources with medical application prospects, and the combination may share their advantages to drive the overcoming of the long-lasting hurdles in SDVG field. In this review, the advances on SDVGs based on ES matrices and SCs (including pluripotent SCs, multipotent SCs, and unipotent SCs) are sorted out, and current challenges and future prospects are discussed.

Enhancing biomethanation performance through co-digestion of diverse organic wastes: a comprehensive study on substrate optimization, inoculum selection, and microbial community analysis.

A blend of organic municipal solid waste, slaughterhouse waste, fecal sludge, and landfill leachate was selected in different mixing ratios to formulate the best substrate mixture for biomethanation. Individual substrates were characterized, and the mixing ratio was optimized with the help of a response surface methodology tool to a value of 1:1:1:1 (with a C/N ratio of 28±0.769 and total volatile fatty acid (VFA) concentration of 2500±10.53 mg/L) to improve the overall biomethanation. The optimized blend (C/N ratio: 28.6, VFA: 2538 mg/L) was characterized for physicochemical, biological, and microbial properties and subjected to anaerobic digestion in lab-scale reactors of 1000 mL capacity with and without the addition of inoculum. The biogas yield of individual substrates and blends was ascertained separately. The observed cumulative biogas yield over 21 days from the non-inoculated substrates varied between 142±1.95 mL (24.6±0.3 ml/gVS) and 1974.5±21.72 mL (270.4±3.1 ml/gVS). In comparison, the addition of external inoculation at a 5% rate (w/w) of the substrate uplifted the minimum and maximum cumulative gas yield values to 203±9.9 mL (35.0±1.6 mL/gVS) and 3394±13.4 mL (315.3±1.2 mL/gVS), respectively. The inoculum procured from the Defence Research and Development Organisation (DRDO) was screened in advance, considering factors such as maximizing VFA production and consumption rate, biogas yield, and digestate quality. A similar outcome regarding biogas yield and digestate quality was observed for the equivalent blend. The cumulative gas yield increased from 2673±14.5 mL (373.7±2.2 mL/gVS) to 4284±111.02 mL (391.47±20.02 mL/gVS) over 21 days post-application of a similar dosage of DRDO inoculum. The 16S rRNA genomic analysis revealed that the predominant bacterial population belonged to the phylum Firmicutes, with the majority falling within the orders Clostridiales and Lactobacillales. Ultimately, the study advocates the potential of the blend mentioned above for biomethanation and concomitant enrichment of both biogas yield and digestate quality.

Chitosan-based electroconductive inks without chemical reaction for cost-effective and versatile 3D printing for electromagnetic interference (EMI) shielding and strain-sensing applications.

The burgeoning interest in biopolymer 3D printing arises from its capacity to meticulously engineer tailored, intricate structures, driven by the intrinsic benefits of biopolymers-renewability, chemical functionality, and biosafety. Nevertheless, the accessibility of economical and versatile 3D-printable biopolymer-based inks remains highly constrained. This study introduces an electroconductive ink for direct-ink-writing (DIW) 3D printing, distinguished by its straightforward preparation and commendable printability and material properties. The ink relies on chitosan as a binder, carbon fibers (CF) a low-cost electroactive filler, and silk fibroin (SF) a structural stabilizer. Freeform 3D printing manifests designated patterns of electroconductive strips embedded in an elastomer, actualizing effective strain sensors. The ink's high printability is demonstrated by printing complex geometries with porous, hollow, and overhanging structures without chemical or photoinitiated reactions or support baths. The composite is lightweight (density 0.29 ± 0.01 g/cm3), electroconductive (2.64 ± 0.06 S/cm), and inexpensive (20 USD/kg), with tensile strength of 20.77 ± 0.60 MPa and Young's modulus of 3.92 ± 0.06 GPa. 3D-printed structures exhibited outstanding electromagnetic interference (EMI) shielding effectiveness of 30-31 dB, with shielding of >99.9 % incident electromagnetic waves, showcasing significant electronic application potential. Thus, this study presents a novel, easily prepared, and highly effective biopolymer-based ink poised to advance the landscape of 3D printing technologies.