Blend Composition Research Articles

Effects of extrusion on nutritional and non-nutritional properties in the production of multigrain ready to eat snacks incorporated with NUA45 beans

Background: Extrusion technology, used in producing a variety of food products, including ready-to-eat snacks, has become a popular and reputable industrial method. Snacks have been occupying an important part of the diet for the world's population. However, the effects of extrusion on nutritional and non-nutritional properties in the production of snacks using traditional grains incorporated with legumes are not fully understood. Objective: To determine the effects of extrusion on nutritional and non-nutritional qualities of multigrain puffs from white sorghum, pearl millet and NUA45 beans. Methods: White sorghum, pearl millet and NUA45 beans were blended in the ratios 50:30:20, 50:20:30 and 50:10:40% to select the best composite for snack production. Selected nutritional and non-nutritional quality parameters were compared before and after extrusion. Results: The extrusion process caused a significant increase (p < 0.05) in the content of fat (2.22 to 2.61%, 1.73 to 2.40 and 2.75 to 3.29% for the blends 1, 2 and 3 (50:30:20, 50:20:30 and 50:10:40% respectively), while causing a decrease in protein content, 14.44 to 13.34%, 16.63 to 13.34% and 20.56 to 16.41% in the multigrain puffs. Extrusion also increased iron, zinc and sodium content significantly (p < 0.05) while decreasing calcium. Magnesium and phosphorus had no change. Furthermore, extrusion improved the multigrain puffs' nutritional value and antioxidant activity. The extrusion process caused a significant decrease in tannins (6.82 to 6.01%, 7.82 to 2.17% and 5.74 to1.17%) and phytates contents (2.82 to 2.43%, 3.01 to 1.55% and from 2.92 to 0.37%) of the resultant multigrain puffs from blends 1,2 and 3 respectively. Total phenolic content increased (18.56 to 172.22, 24.38 to 144.61, and 65.87 to 180.44 mg GAE/100g). Conclusion: Extrusion enhances selected nutrients while decreasing anti-nutrients. Based on the composite feeds of white sorghum, pearl millet and NUA45 beans analyzed, the composite blend in the ratio 50:10:40% can be used to develop an acceptable novel healthy extruded traditional grain-based snack. Keywords: Extrusion, ready-to- eat snacks, multigrain puffs, nutrients, anti-nutrients, white sorghum, pearl millet, NUA45 beans.

Functional composites by programming entropy-driven nanosheet growth.

Nanomaterials must be systematically designed to be technologically viable1-5. Driven by optimizing intermolecular interactions, current designs are too rigid to plug in new chemical functionalities and cannot mitigate condition differences during integration6,7. Despite extensive optimization of building blocks and treatments, accessing nanostructures with the required feature sizes and chemistries is difficult. Programming their growth across the nano-to-macro hierarchy also remains challenging, if not impossible8-13. To address these limitations, we should shift to entropy-driven assemblies to gain design flexibility, as seen in high-entropy alloys, and program nanomaterial growth to kinetically match target feature sizes to the mobility of the system during processing14-17. Here, following a micro-then-nano growth sequence in ternary composite blends composed of block-copolymer-based supramolecules, small molecules and nanoparticles, we successfully fabricate high-performance barrier materials composed of more than 200 stacked nanosheets (125 nm sheet thickness) with a defect density less than 0.056 µm-2 and about 98% efficiency in controlling the defect type. Contrary to common perception, polymer-chain entanglements are advantageous to realize long-range order, accelerate the fabrication process (<30 min) and satisfy specific requirements to advance multilayered film technology3,4,18. This study showcases the feasibility, necessity and unlimited opportunities to transform laboratory nanoscience into nanotechnology through systems engineering of self-assembly.

Composition of bacterial blends for fermentation-induced pea protein emulsion gels using multi-property screening of lactic acid bacteria

In this study, a comprehensive screening and identification process to pinpoint lactic acid bacteria (LAB) strains capable of enhancing gel firmness and elevating the flavor profile in pea protein-based protein gels was conducted, aiming to demonstrate how tailored starter cultures for specific applications can provide high-quality sensory attributes in fermented plant-based cheese. Thirteen single strains were selected from a poll of 90 different LAB based on their acidification performance, contribution to gel firmness, removal of off-flavors and production of dairy-associated volatile organic compounds. They were combined in 64 different blends of five strains each and screened again for the same parameters. Fast acidifying strains were prioritized for food preservation reasons to inhibit undesirable spoilage. Fermentation of pea protein emulsions with Streptococcus thermophilus, Lactobacillus, and Lactococcus blends resulted in a significant reduction in volatile organic compounds associated with beany and green off-flavor, a production of dairy-associated compounds, and satisfactorily contributed to gel firmness.

Nutritional quality and physicochemical properties of biscuit from composite flour of wheat, African yam bean and tigernut

This study investigated the effect of the supplementation of wheat flour with flour blends of African yam bean (AYB) and tigernut for the production of biscuits and evaluated the sensory characteristics. The composite flours were of ratio 70:25:5 (TWB), 70:20:10 (ATW), 70:15:15 (BTT) for wheat: AYB: tigernut, respectively, while 100 % wheat flour served as control (WTY). The composite flour samples were analyzed for proximate, functional and pasting properties. The physical and chemical properties and sensory attributes of the developed biscuits were carried out. The moisture, protein, fat, ash, crude fiber, carbohydrate, and energy contents of the composite flour ranged from 6.63 to 8.13 %, 11.22–18.36 %, 13.27–19.15 %, 0.98–0.99 %, 3.96–7.43 %, 59.97–62.55 % and 400.89 to 410.40 Kcal/100g, respectively. The results showed that protein fat, ash and crude fiber of the biscuit were improved. The water and oil absorption capacity of composite flour was low while the pasting properties of the composite flour blends reduced as the AYB flour increased. All the composite flour blend biscuit samples possessed high essential nutrients and antioxidant potential. All the biscuits samples were accepted by the panelists, however, sample BTT (70 % wheat flour+15 % AYB flour+ 15 % tigernut flour) was most accepted in appearance, aroma, taste, crispness and overall acceptability. Therefore, biscuits from the flour blends of wheat, AYB and tigernut could be nutritionally beneficial and good for adults.

Thermoplastic extrusion technology as a tool for adding value to brewer's by-products

Brewer's by-products show high nutritious potential to be reintegrated into the food chain. Nevertheless, their high moisture, microbiological instability, and heterogeneity pose enormous challenges. This study investigated thermoplastic extrusion to repurpose large amounts of the two main brewery by-products: brewer's spent grains (BSG) and brewer's spent yeast (BSY). A mixture design was used to compose ten blends with different proportions of dried-BSG, BSY, and corn grits, maximizing the use of BSG up to 70 g/100 g. Extruder parameters were fixed. PLS regression was applied to evaluate the effects of blend composition on the characteristics of the extruded products. Thermoplastic extrusion shows feasibility in transforming large volumes of by-products into value-added products. Blends with high insoluble fiber, protein, and moisture contents resulted in extrudates with high protein concentration, low expansion, and high density. The results of this exploratory work can be used for product optimization by choosing nutritional, technological, and commercial targets to create innovative, healthy, and sustainable food products that meet consumer demands.

Density, Viscosity, and Distillation Temperatures of Binary Blends of Diesel Fuel Mixed with Oxygenated Components at Different Temperatures

This paper reports density, kinematic viscosity, and distillation curves for blends of diesel fuel with n-butanol, diesel fuel with n-pentanol, and diesel fuel with diethylene glycol dimethyl ether. It is known that these properties affect not only fuel transportation and distribution processes but also the phenomena that occur in an internal combustion engine; therefore, these aspects are intriguing to study. Oxygenated compounds such as n-butanol, n-pentanol, and diethylene glycol dimethyl ether can be used as additives for diesel fuel. Their use can contribute to a significant improvement in the fuel’s ignitability due to their high oxygen contents. Measurements of the experimental properties of various blend compositions were carried out at temperatures ranging between 288.15 K and 323.15 K. Based on density and viscosity data, different mathematical models were verified for the purpose of establishing better quality standards for the production of fuel. Good accuracies were obtained in the cases of density, viscosity, and interaction parameters, with the largest average absolute deviation (AAD%) being 0.4351. Moreover, as the determination of density is uncomplicated, rapid, and requires small sample volumes, correlations with the distillation temperatures used for the fuel blends were investigated to estimate the samples’ cetane indices. These determinations will be useful in the automobile industry when designing transport equipment or pipelines in situations when oxygenated compounds may constitute a fuel component in diesel blends.

Biochar from Digestate Pyrolysis as a Filler for Biopolymer Blends: Effect of Blend Composition

Abstract This study investigates the effect of biochar (BC) as a filler for biopolymer blends, with a focus on the effect of the biopolymer weight ratio on the final BC-added blends. The blends studied in this work were obtained by varying the weight ratio of poly-butylene adipate-co-terephthalate (PBAT) and polylactic acid (PLA) due to their great importance in packaging and agricultural fields. BC has been produced in our laboratories by the slow pyrolysis of the digestate obtained from the anaerobic digestion of the organic fraction of municipal solid waste (OFMSW). After pyrolysis, digestate-derived biochar has been milled and sieved to produce a powdery form with diameter of less than 45 μm. In order to better investigate the filler/polymer interactions, biochar particles were dimensionally, morphologically and chemically characterised. The inhomogeneity of the feedstock is responsible for content and high diversity of inorganics in biochar surface. The effect of BC on PBAT and PLA biopolymer matrices is different, and for the blend compositions the relative weight ratio between PBAT and PLA plays an important role. Furthermore, the biocomposite blend has been fully characterised: rheological, morphological, mechanical and dynamic-mechanical characterisations have been carried out, highlighting how the properties results strongly influenced by the presence of BC in the blend. In addition, a study of the viscous molar mass of the two polymer matrices when processed in the presence or absence of BC particless highlighting that a strong chemical interaction occurs between PLA and BC particles, unlike PBAT and BC. Graphical Abstract

Two‐dimensional Ti3C2Tx (MXene)‐multiwalled carbon nanotubes reinforced ethyl methyl acrylate/ethylene octene copolymer binary blend hybrid nanocomposites with enhanced thermal and dielectric properties

AbstractPolymer composites with high dielectric constant and minimal dielectric losses have wide ranging prospects for advanced applications in the flexible electronics and electrical industry. In this study, we used the advantages of carbonaceous hybrid nanofillers to develop a flexible dielectric material. Herein, a set of hybrid nanocomposites were successfully fabricated by incorporating the Ti3C2Tx (MXene) and MWCNTs (multi‐walled carbon nanotubes) hybrid mixture as the conductive moiety into the poly(ethylene‐co‐methyl acrylate) (EMA)/ethylene‐octene co‐polymer (EOC) binary blend as the matrices using solution mixing technique followed by compression molding. As prepared, EMA/EOC/Ti3C2Tx/MWCNTs hybrid composites have been characterized by FTIR (Fourier transform infrared) spectroscopy, XRD (X‐ray diffraction), TGA (thermogravimetric analysis), FESEM (field emission scanning electron microscopy), and DSC (differential scanning calorimetry). We studied the effects of Ti3C2Tx and MWCNTs contents in the hybrid composites on the thermal, dielectric, and electrical properties. Among all the 15 wt% hybrid mixture containing 2 wt% MWCNTs loaded composite has the highest dielectric constant (ℇr = 122.21) and the lowest dissipation loss (tan δ = 0.030) at 100 Hz. The present studies recommend the EMA/EOC/Ti3C2Tx/MWCNTs hybrid composites can be used in smart and flexible electronic storage material.Highlights EMA‐EOC blend composites with hybrid Ti3C2Tx/MWCNTs were processed. 2.5 wt% MWCNTs loaded hybrid composite shows excellent thermal stability. Composite with 2 wt% MWCNTs has ℇ' = 122.21 and tanδ = 0.03 at 100 Hz. 2.5 wt% MWCNTs composite has electrical conductivity of 3.26 × 10−8 Ω−1 m−1. This composite can be used in smart and flexible electronic storage material.

Occurrence of mycotoxins, phytoestrogens and other fungal metabolites in Ready-to-Use Therapeutic Foods for severely and acutely malnourished children

Ready-to-Use Therapeutic Foods (RUTFs) are mainly legumes- or nut-based low moisture, high energy and nutrient dense ready-to-eat foods strictly designed to treat severe acute malnutrition (SAM) in children. Despite the critical application of this food in a highly vulnerable population, there is no information on the spectrum of mycotoxins in RUTFs globally. This study therefore assessed 41 RUTF samples available in northern Nigeria for multiple mycotoxins using LC-MS/MS. Sixteen mycotoxins and 31 other metabolites comprising phytoestrogenic phenols, plant toxins and metabolites from diverse fungi were detected in the RUTF samples. The mycotoxins include aflatoxin B1 (AFB1), citrinin (CIT), deoxynivalenol, enniatins, alternariol methyl ether, moniliformin, sterigmatocystin, zearalenone, and their derivatives. AFB1 was detected in 5% of the samples at concentrations below the Codex Alimentarius maximum limit of 5 μg/kg, but exceeded the stricter 0.1 μg/kg European Union limit for baby/infant foods by 4–19 times. The highest mean mycotoxin concentration (42 μg/kg) was recorded for CIT, whereas enniatin B was the most occurring (73%). For other metabolites, abscisic acid and cordycepin were the most frequently occurring (100%), while genistin, a phytoestrogenic isoflavone, had the highest mean of 15,751 μg/kg. RUTF from composite flour blends had more mycotoxins compared to those made from peanuts. This is the first study on mycotoxin occurrence in RUTFs. Further studies are needed to assess the presence of mycotoxins and other metabolites in RUTFs on a larger scale as well as the associated risks from their occurrence in view of the high vulnerability of SAM children who consume the foods.

Continuous Spectrum of Morphologies and Phase Behavior across the Contact Zone from Poly(l-lactide) to Poly(d-lactide): Stereocomplex, Homocrystal, and Between.

The enantiomeric ratio is a key factor affecting the crystallization behavior and morphology of poly-l-lactide/poly-d-lactide (PLLA/PDLA) blends. Despite a number of studies on crystallization of nonequimolar PLLA/PDLA blends, a full picture of the effect of the L/D ratio is still lacking. Here, we put the two enantiomers in contact and allow interdiffusion above the melting point of the stereocomplex crystal (SC) to prepare samples with a continuously changing L/D ratio from enantiopure PLLA (ratio 0/100) to enantiopure PDLA (100/0). Using polarized optical microscopy, atomic force microscopy, and microbeam X-ray diffraction, the continuous spectrum of morphologies and phase behaviors across the contact zone is investigated. The blend morphology shows clear evidence of "poisoning by purity" of SC crystallization at all blend compositions. The low birefringence of the 50/50 SC is found to be due to the meandering of broken edge-on lamellae. Its further decrease to near zero as L/D deviates further away from 50/50 is explained by transition from radial edge-on lamellae to fully random meandering lamellae, then to mixed flat-on lamellae, and finally to submicron-sized axialites. In comparison with the smooth and straight homocrystal (HC) lamellae of pure enantiomers, the lamellae in the blends often have serrated edges caused by pinning by rejected excess enantiomer acting as an impurity during lamellar growth. A feature of the binary phase diagram is pure enantiomers acting as an impurity to the SC and counter-enantiomer acting as an impurity to homocrystallization of the enantiomers. Crystallization was found to be most suppressed at 99% enantiomeric purity, where the amount of the counter-enantiomer is insufficient for creation of SC nuclei and HC growth is inhibited by the small amount of the enantio-impurity. These and other intriguing results are less likely to be noticed without the continuous composition gradient of the contact sample.

PRODUCTION AND QUALITY EVALUATION OF ENRICHED BREAD FROM FLOUR BLENDS OF WHOLE WHEAT, BAMBARA NUT, SOYBEANS AND CASHEW NUT SEED

Bread is a staple food prepared from dough of flour and water, usually by baking. Throughout recorded history, bread has been very popular around the world. It is one of humanity’s oldest foods, having been of great importance since the dawn of Agriculture. The major ingredient in bread production is wheat flour which is very expensive. The study was conducted to produce enriched bread from composite flour blend of whole wheat, soybeans, bambara nut and cashew nut seed. Four samples were produced of varying ratio mixes and then subjected to proximate, microbiological and sensory evaluation analysis. The result from the proximate analysis indicated that the nutritional value of the product increased significantly with the incorporation of flour composite. Sample A was rated highest for moisture (26%), sample B (16%) ash, sample C (18.5%) protein, (15.8%) fat respectively. Also sample C was the most accepted in terms of sensory qualities indicating improved bread quality. The result for micro biological qualities of the product indicated that the product is fit for human consumption. An enriched and nutritious adequate bread can be produced by substituting whole wheat flour with other flour composite. The study therefore based on its findings recommended that the product should be subjected for mineral and vitamin analysis to determine the micro nutrient content of the product and also its anti- nutritional composition.

Cytotoxic-Ag-Modified Eggshell Membrane Nanocomposites as Bactericides in Concrete Mortar.

Against the backdrop of escalating infrastructure budgets worldwide, a notable portion-up to 45%-is allocated to maintenance endeavors rather than innovative infrastructure development. A substantial fraction of this maintenance commitment involves combatting concrete degradation due to microbial attacks. In response, this study endeavors to propose a remedial strategy employing nano metals and repurposed materials within cement mortar. The methodology entails the adsorption onto eggshell membranes (ESM) of silver nitrate (ESM/AgNO3) or silver nanoparticles (ESM/AgNPs) yielding silver-eggshell membrane composites. Subsequently, the resulting silver-eggshell membrane composites were introduced in different proportions to replace cement, resulting in the formulation of ten distinct mortar compositions. A thorough analysis encompassing a range of techniques, such as spectrophotometry, scanning electron microscopy, thermogravimetric analysis, X-ray fluorescence analysis, X-ray diffraction (XRD), and MTT assay, was performed on these composite blends. Additionally, evaluations of both compressive and tensile strengths were carried out. The mortar blends 3, 5, and 6, characterized by 2% ESM/AgNO3, 1% ESM/AgNPs, and 2% ESM/AgNPs cement replacement, respectively, exhibited remarkable antimicrobial efficacy, manifesting in substantial reduction in microbial cell viability (up to 50%) of typical waste activated sludge. Concurrently, a marginal reduction of approximately 10% in compressive strength was noted, juxtaposed with an insignificant change in tensile strength. This investigation sheds light on a promising avenue for addressing concrete deterioration while navigating the balance between material performance and structural integrity.

The implication of PMMA molecular weight on compatibility of SAN/PMMA blends containing GO-g-PMMA hybrid compatibilizers

The molecular weight of a polymer is one of the most important factors defining material properties and performance. Within the current study, poly(styrene-co-acrylonitrile)/poly(methyl methacrylate) (SAN/PMMA) blends containing hybrid particles of graphene oxide-g-poly(methyl methacrylate) (GO-g-PMMA) were designed so that the molecular weight of the PMMA chains tethered on the GO particles was correlated with the molecular weight of the PMMA matrix. Hybrid particles were prepared using surface-initiated atom transfer radical polymerization (ATRP). The number average molecular weight of the matrix PMMA was Mn = 20,100 or 130,900 g/mol, while in the case of hybrids it was Mn = 5600, 27,300 or 191,600 g/mol. Two blend compositions were investigated: SAN/PMMA= 70/30 and 90/10 wt/wt, and the content of GO-g-PMMA was 1 wt%. Based on rheological studies it was demonstrated that higher molecular weights of the matrix PMMA promoted the compatibility of SAN/PMMA due to the similar viscosity of both blend components. Furthermore, the length of the PMMA chains grafted to the GO influenced the viscoelastic response of the material, resulting in different relaxation behavior as confirmed by mean relaxation times calculated from Cole-Cole plots. In addition, the effect of neat GO and GO-g-PMMA particles on the blend morphology and size distribution of PMMA droplets was discussed based on rheology and TEM analyses.

Compatibility–structural color property relationship of binary blends of acetylated hydroxypropyl celluloses with different degrees of acetylation

AbstractPolymer blends containing liquid crystalline cellulose derivatives potentially enable the fabrication of optical functional materials because of their unique optical properties, that is, structural color and circular dichroism. However, studies on the effect of the compatibility of the components on the optical properties of such blends are scarce, even though component compatibility is a crucial factor for the physical properties of the polymer blends. In this study, we investigated the effect of the component compatibility on the structural color property of binary blends of acetylated hydroxypropyl celluloses (AHPCs) with different degrees of acetylation (DSAc). The spectroscopic analyses of the AHPC blends revealed that the structural color of blends with a small DSAc gap between AHPC components systematically changed with the blend composition, whereas the color of blends with a large DSAc gap was independent of the composition. Compatibility tests via spin–lattice relaxation time measurements using solid‐state nuclear magnetic resonance indicated that the different composition dependence of the color was attributed to the compatibility of the components, which varied according to the DSAc gap.

Rice husk fibers and their extracted silica as promising bio-based fillers for EPDM/NBR rubber blend vulcanizates

Bio-based natural wastes could be considered eco-friendly alternatives to conventional fillers for enhancing the properties and reducing the cost of final rubber products. Thus, in the present research, EPDM/NBR rubber blend composites filled with kaolin and mixed with rice husk fibers (RHFs) were prepared. Homogeneity of the EPDM/NBR blends was improved by the incorporation of maleic anhydride (MAH) as a compatibilizing agent (1 phr), as evidenced by scanning electron microscopy (SEM). Of all EPDM/NBR blend ratios investigated, the 25/75 blend revealed good mechanical properties, thermal stability, and the least weight swell at equilibrium (Q%) in motor oil and brake fluid. EPDM/NBR/kaolin (25/75/30) blend vulcanizates containing RHFs at various loadings demonstrated a significant improvement in swelling resistance, primarily in motor oil and brake fluid, accompanied by a slight reduction in the mechanical properties at high RHFs content. That was complemented by the enhancement of thermal stability of the rubber blends, as demonstrated by TGA analysis. Among the filler types investigated (RHFs, silica ash (SA), rice husk silica (RHS), and kaolin), RHFs exhibited the best swelling resistance of the composite vulcanizates in motor oil and brake fluid. In addition, RHS could be used successfully as a supporting filler for carbon black-reinforced EPDM/NBR composite vulcanizates because it enhanced their thermal stability and swelling resistance in the motor oil.Graphical

Morphology and Mechanical Properties of Poly(vinyl alcohol)/Poly(lactic acid) Blend Films Prepared from Aqueous Dispersions

AbstractIn this study, the preparation of poly(vinyl alcohol) (PVA)/poly(lactic acid) (PLA) blends of different compositions, 100/0, 75/25, 50/50, 25/75, and 0/100, by mixing water solutions of the former and water dispersions of the latter polymer, is reported. Two distinct dispersions of PLA are prepared using a commercial‐grade polyester and two different surfactants, an anionic one and a neutral one. Films of PLA and of the corresponding blends are obtained by simply drying at 60 °C the water dispersions without or with the PVA. The films are characterized by infrared spectroscopy, differential scanning calorimetry (DSC), and scanning electron microscope (SEM) analysis. This evidences an island‐like morphology, with the continuous phase consisting of a PVA rich phase at all compositions except 25/75, for which an inverted phase composition, with a continuous phase made mostly of PLA, is instead found. Voids caused by air bubbles trapped in the initial mixture are observed in particular in the formulations with the anionic surfactant. The trapped bubbles result in premature thermal degradation by thermogravimetric analysis (TGA) and mechanical failure during clamping. Films with the neutral stabilizer are tougher than the bare commercial PLA, with Young modulus and elongation at break depending on the combination of the composition and arrangement of blend phases.

Synthesis and characterization of electrospun composite nanofibers from Moringa oleifera biomass and metal oxide nanoparticles as potential adsorbents for the removal of lead ions

AbstractElectrospun multicomposite nanofibers synthesized from extracts of Moringa oleifera (M. oleifera) seed biomass blended with metal oxide nanoparticles (MONPs) and polyacrylonitrile (PAN) were investigated as potential adsorbents. The materials were characterized using SEM, XRD, FTIR, BET and TGA. The specific surface area of MONPs ranged between 29.75 and 60.92 m2/g and their incorporation in the PAN/M. oleifera composite blend resulted in increased surface coarseness and larger nanofiber diameters (268 ± 21–317 ± 27 nm). The application of PAN/M. oleifera/MONPs for Pb(II) removal from aqueous solution via batch adsorption experiments was investigated based on the parameters: solution pH, contact time and initial Pb(II) ion concentration. Experimental results better fitted the Langmuir isotherm model and pseudo-second-order kinetics. Adsorption capacities ranged between 172.4 and 227.3 mg/g. These results demonstrate that low-cost indigenous materials have significance and applicability in water remediation applications.

Lost circulation material design for near-wellbore transverse fractures

The use of particulate lost circulation material (LCM) in drilling fluid is a common method for mitigating lost circulation from near-wellbore fractures that develop during subterranean drilling. Fracture width estimation is the center piece of designing the particle size distribution (PSD) of LCM blends. Width estimation of near-wellbore fractures has predominantly been based on assuming axial fracture development from wellbores. However, this assumption is not valid for all wellbore orientations. Shallow vertical and highly inclined or horizontal well sections in a normal subsurface faulting regime may give rise to configurations where drill-induced fractures develop transverse to the wellbore axis. A transverse fracture yields a substantially different width compared to an axial fracture. This study aims to demonstrate the width contrast between the two fracture geometries and the impact that such contrast would have on the LCM blend design. For this purpose, the width of near-wellbore transverse fractures is estimated using a linear elastic fracture mechanics solution to an axisymmetric model of the same. Contrary to the case of hydraulic fractures, the solution must consider the effect of wellbore cavity boundary conditions on the fracture width profile. Two case studies involving horizontal and vertical boreholes are examined. Results indicate that the assumption of axial fracture geometry could lead to substantial underestimation or overestimation of the fracture width depending on the wellbore inclination and magnitudes of the in-situ stress components. Application of the solution in selecting the compositions of blends made from three LCMs is demonstrated. The discrepancy between the LCM blends PSDs obtained based on the axial and transverse models of the wellbore fracture are discussed.

Facile synthesis of PVA-formamide based solid state electrolyte membrane: A combined experimental and computational studies

For ever-growing energy demand, it is the imperative of time to develop advanced electrolyte materials which are compatible with Li + ion mobility in Lithium based batteries. In this study, polyvinyl alcohol (PVA)-LiNO3-Formamide (PLF) membrane complex has been developed for cost effective and mass fabrication of Li ion based energy storage devices. Improved Li + ion conducting PVA based polymer electrolytes in seven different PVA and LiNO3 blend compositions were prepared and characterized. Incorporation of Formamide (0.5 g) as plasticizer in the PVA-LiNO3 polymer matrix leads to a remarkable improvement in ionic conductivity (4.18 × 10−4 Scm−1) for a 0.27 g of LiNO3 concentration at ambient temperature. Improvement in Li conductivity is due to change in crystalline nature as a consequence of PVA O-H---O intra/inter molecular H-bonding destabilization. Investigation on the trend of activation energy as a function of dopant concentration indicates that the activation energy decreases up to 0.27 g of LiNO3. Lowest activation energy 0.21 eV is observed for this concentration. More interestingly, improved Lithium Transference Number (LITN) of 0.437 is obtained through Bruce-Vincent approach for the plasticized optimum conducting membrane (PLF4–0.27 g LiNO3 concentration) which is better than that of the commercially available Li batteries. Underlying molecular level interactions in the models of PVA and its complexes were explored using M05-2×/6–31 + G (d,f) levels of theory and NCI analysis. From the least interaction energy of PVA-Formamide complex, it is inferred that metal-Oxygen coordination contributes much for the stabilization of PVA-LiNO3-Formamide, PVA-LiNO3, Formamide-LiNO3 complexes.

Roles of Blend Morphology and Energy Level Alignment in Determining Open‐Circuit Voltage and Fill Factor of Ternary All‐Polymer Solar Cells

AbstractTuning the open‐circuit voltage (VOC) and fill factor (FF) without sacrificing the short‐circuit current density is crucial for achieving performance advantages in ternary blend organic solar cells as an alternative to the binary ones. This study investigates ternary all‐polymer solar cells comprised of two polymer donors (D1 and D2) and one polymer acceptor (A), using two types of D2 polymers with different compatibilities with D1. As demonstrated by photoelectron yield spectroscopy, the ionization energy (IE) of the ternary blends continuously shifts between the IEs of D1:A and D2:A binary blends when D2 forms a single indistinguishable domain with D1. In contrast, the IE of the blends does not exhibit any noticeable change when D2 induces distinct phase separation with D1. Models describing the blend composition dependence of the VOC and FF are constructed by correlating the effects of the blend morphology and the shift in the energy level of the hole‐transporting state in the ternary blends. This study demonstrates that a pseudo‐binary blend morphology with a mixed D1 and D2 donor domain and an A acceptor domain is necessary to obtain a broad tunability of VOC and tolerance of FF to the blend composition in ternary all‐polymer solar cells.