Increase In Solid Content Research Articles

Use of a biocompatible polymer to enhance tailings transportation and reduce water consumption at a coper-cobalt-zinc plant

Excess water can lead to instability and even failure in tailings storage facilities (TSFs). Simply reducing the amount of water in TSFs could be the best way to ensure the safety of nearby communities. In this case study we investigated the effects of reducing the water content in tailings slurry at a copper-cobalt-zinc mine in Mexico. An environmentally friendly polymer was used as a drag reduction agent (DRA) to offset the increase in solids percentage. The potential effects of the increased solids concentration on the tailings transportation system were also assessed. A series of 'what if' studies was conducted to assess whether adding the polymer would allow the solids concentration to be increased without changing the pressure loss in the tailings pipeline. The studies entailed conducting pipe loop tests to investigate these changes under various solids/ polymer concentrations and then constructing a computational fluid dynamics (CFD) simulation model using the test results. The validated model was used to determine the optimal polymer percentages needed to maintain the same pressure loss under baseline (30% solids) conditions, and to assess the potential risks (clogging, increased erosion rates) to the pipelines. The potential water savings were found to be significant, varying from about 1.852 Mm3/a at 35% solids to 3.915 Mm3/a at 45% solids.

Potensi Produksi Biohidrogen dari Limbah Buah Naga (hylocereus polyhizus) dengan Proses Pencernaan Anaerobik

This research aims to explore the potential of dragon fruit waste as a source of biohydrogen through anaerobic fermentation. The research background highlights the urgency of renewable energy and identifies the potential for dragon fruit waste. Using experimental methods and involving dragon fruit waste and cow dung, this research includes evaluation of waste characteristics, inoculum pre-treatment, medium preparation, biohydrogen production, and analysis of results. The research results show that Total Solids (TS) has increased every day, indicating that there is still high decomposition of organic material which affects biohydrogen production. The test results showed that the TS percentage experienced a significant increase in solids content reaching 96% on the seventh day, while the VS percentage increased from 19% on the first day to 80% on the seventh day. The increase in Volatile Fatty Acid (VFA) concentration and hydrogen production on the sixth day illustrates the potential of waste as a renewable energy source. The conclusion of this research states that dragon fruit waste has the potential for biohydrogen production of 4 mL from a substrate volume of 500 mL or around 0.8%.

Characterization of novel lamellar porous Ti3SiC2 as shape-stabilized high-temperature phase change materials composites for durable enhancement thermal storage properties

In pursuit of leveraging porous media for high-temperature phase change materials (PCMs) to enhance the overall thermal conductivity and encapsulation performance of PCMs, this study delves into the corrosion behavior of Ti3SiC2 with a lamellar porous structure in different corrosive environments at both high and low temperatures. By manipulating the solid content to modify the porous structure, the investigation probes the corrosion phenomena and anti-corrosion mechanisms across various porous configurations. The results reveal that F ions exert the most extensive structural degradation on Ti3SiC2. Based on these insights, a successful fabrication of a molten salt phase change composite material, Ti3SiC2/KCl-NaCl, boasting a lamellar structure was achieved. With an increase in solid content, the thermal conductivity escalates from 6.13 to 9.27 W/(m∙K), tripling the heat conductivity of pure KCl-NaCl. However, this also leads to a reduction in latent heat from 126.7 J/g to 46.2 J/g. Consequently, the phase change energy storage performance of PCM prepared by sample 2 emerges as exceptionally commendable. Following 200 thermal cycles on the composite PCM, no discernible structural damage was observed, albeit a slight performance decline. Hence, the lamellar Ti3SiC2/KCl-NaCl structure not only boasts favorable phase change energy storage capabilities but also demonstrates an extended service life.

Differences in primary metabolism related to quality of raspberry (Rubus idaeus L.) fruit under open field and protected soilless culture growing conditions.

The raspberry (Rubus idaeus) fruit is characterized by good taste and high acceptability by consumers. Thus, the impact on the quality attributes and metabolites related to raspberry taste should be evaluated in crop alternatives such as the protected soilless culture. This study aimed to evaluate the metabolic changes during fruit development and postharvest of raspberry grown in open field and protected soilless culture and their relationship with quality parameters and sensory perception. In this study, the quality parameters and polar metabolites -sugar and amino acids- content were evaluated during raspberry ripening. In addition, ripe fruit was stored at 1 °C for five days, followed by one day of shelf life at 20 °C. The physiological and quality parameters showed typical changes during ripening in both growing conditions: a constant production of CO2, a drastic loss of firmness, an increase in weight and soluble solids content, loss of acidity, and a turning to red color from the green to fully ripe fruit stages in both growing conditions. Fruit from the protected soilless culture had significantly higher weight but a lower soluble solids content. The metabolic analysis showed differences in primary metabolites content during ripening and storage at 1 °C between both growing conditions. The raspberries grown in the open field showed higher contents of sugars such as D-glucose and D-fructose. On the contrary, the fruit from the protected soilless culture showed higher contents of some amino acids such as L-alanine, L-serine and L-valine, among others. The sensorial panel showed significant differences in the perception of the sweetness, acidity, color and firmness of ripe fruit from both growing conditions. The present study provides interesting and useful results with direct commercial application for this alternative growing system, mainly in areas where soil and water scarcity are a reality.

Bio-based nanomaterial suspensions as sprayable coatings for maintaining blueberry postharvest quality

The growing concerns about postharvest fruit spoilage demand sustainable active coating materials with high performance. In this work, bioactive spray coating suspensions were developed for the postharvest preservation of blueberries using chitosan, cellulose, and lignocellulose nanofibers (ChNFs, CNFs, and LCNFs), sodium alginate (SA), and tea tree essential oil (TTO). Characteristics, including the rheological properties of coatings and the effect on physicochemical postharvest quality parameters of blueberry fruit were investigated. The nanomaterials and SA were shown to make stable and sprayable coating suspensions with high surface charge (zeta potential value of −61.3 mV), shear thinning behavior, steady viscosity, and outstanding viscoelastic behavior from their ability to restore fibrous network structure and ion strength of SA to inhibit nanofibers aggregation. The coatings with LCNFs and SA were more effective in retarding moisture loss of postharvest blueberries during storage compared with coatings without LCNFs and SA. Blueberries coated with ChNF/LCNF/SA/TTO had a soluble solids content (SSC) increase of 16.2% after 15 storage days, while uncoated and other coated blueberries had more than a 21.7% SSC increase. In addition, the ChNF/LCNF/SA/TTO coating had an entangled matrix structure and enhanced hydrophobicity, improving gas barrier performance on the blueberry surface. As a result, the coating was able to preserve the moisture, stiffness, firmness, and individual sugar contents of blueberries during storage. Utilizing nanomaterials and other natural polysaccharides in coatings can offer an economically feasible and sustainable approach for functionalizing biomass materials to preserve fruits.

Plant biostimulants as natural alternatives to synthetic auxins in strawberry production: physiological and metabolic insights.

The demand for high-quality strawberries continues to grow, emphasizing the need for innovative agricultural practices to enhance both yield and fruit quality. In this context, the utilization of natural products, such as biostimulants, has emerged as a promising avenue for improving strawberry production while aligning with sustainable and eco-friendly agricultural approaches. This study explores the influence of a bacterial filtrate (BF), a vegetal-derived protein hydrolysate (PH), and a standard synthetic auxin (SA) on strawberry, investigating their effects on yield, fruit quality, mineral composition and metabolomics of leaves and fruits. Agronomic trial revealed that SA and BF significantly enhanced early fruit yield due to their positive influence on flowering and fruit set, while PH treatment favored a gradual and prolonged fruit set, associated with an increased shoot biomass and sustained production. Fruit quality analysis showed that PH-treated fruits exhibited an increase of firmness and soluble solids content, whereas SA-treated fruits displayed lower firmness and soluble solids content. The ionomic analysis of leaves and fruits indicated that all treatments provided sufficient nutrients, with heavy metals within regulatory limits. Metabolomics indicated that PH stimulated primary metabolites, while SA and BF directly affected flavonoid and anthocyanin biosynthesis, and PH increased fruit quality through enhanced production of beneficial metabolites. This research offers valuable insights for optimizing strawberry production and fruit quality by harnessing the potential of natural biostimulants as viable alternative to synthetic compounds.

Preparation of ZrP2O7-CePO4 composite porous ceramics and their excellent thermal insulation and wave-transmission performance for supersonic aircraft

In this study, a two-step method combining the direct foaming process with the control of solid content and heat treatment temperature was employed to prepare ZrP2O7-CePO4 composite porous materials with varying porosities. The results indicate that an increase in solid content and heat treatment temperature leads to a reduction in porosity and average pore size while simultaneously improving the mechanical properties. The porosities, compressive strengths, thermal conductivities, ε and Tanδ ranged from 63.2 to 85.3 vol%, 19.43 to 0.99 MPa, 0.089 to 0.088 W/(m·K), 1.64 to 2.72, and 0.88 × 10−3 to 1.99 × 10−3, respectively. Electromagnetic simulations have validated that ZrP2O7-CePO4 composite porous ceramics, when used as the core layer material for A-sandwich antenna radomes, exhibit excellent transmittance properties. This suggests the potential application of these materials for supersonic aircraft antenna radomes.

Pilot scale application of a rotating hollow fibre membrane for direct membrane filtration of domestic wastewater

This study investigates the direct ultrafiltration process of municipal wastewater (MWW) at pilot scale. Short-term trials were conducted with two membrane modules to assess the fouling mechanisms using different physical cleaning methods: gas sparging (hydraulic cleaning) and rotation (mechanical cleaning). This work demonstrates that membrane rotation effectively erodes and re-disperses external fouling during the backwashing stages. Consequently, shear stress generated by the rotational movement enables the operation with permeate fluxes ranging between 24 and 30 L/hm2, above the threshold flux value (22–24 L/hm2), while maintaining fouling rates (rf) below 10 Pa/s. In contrast, rf values increases up to 12.4–17.8 Pa/s when gas sparging is employed. Furthermore, the feasibility of up-concentrating municipal wastewater up to 12 times while operating with a net permeate flux of 20 L/hm2 is demonstrated through a long-term trial. The increase in suspended solids concentration (TSS = 5750 mg/L and VSS = 4750 mg/L) favours the rapid formation of a reversible cake on the membrane surface during filtration, at moderate transmembrane pressures (26 cmHg). These operating conditions avoid cake layer compression and protect the inner surface of the membrane module from severe internal residual fouling with an energy consumption of 0.027 kWh/m3.

Application of Coatings in Preservation of Fresh Salak Bali (Salacca zalacca) with Different Emulsions of Fatty Acids

This study aims to determine the effect of emulsion coating of different fatty acids on the characteristics of Salak Bali fruit and to determine the right emulsion formulation. The experimental design used in this study was a simple randomized complete block design (CRD). The treatments were A0: Salak untreated (control). A1: Salak treated with oleic acid, A2: Salak treated with stearic acid, A3: Salak treated with palmitic acid, and A4: Salak treated with a mixture of oleic acid, stearic acid, and palmitic acid. The experiment was repeated three (3) times and observations were made every 3 days until day 15, including: weight loss, total soluble solids, pH, color and organoleptic tests. The results showed that emulsion coating with oleic acid, stearic acid and palmitic acid had a significant effect on the shelf life of Salak Bali fruit. Stearic acid emulsion (1%) is the best emulsion in fruit coating that produces the best fruit characteristics in terms of durability, color, weight loss, pH, suppressing the increase in soluble solids content and is the emulsion that gets the best choice from the calculation of the average number of panelists on organoleptic texture, color and overall acceptability of salak fruit.

Optimization of Isocyanate Content in PF/pMDI Adhesive for the Production of High-Performing Particleboards.

Due to the fact that impregnation with fire retardant usually reduces the strength of the produced particleboards, this research was carried out to investigate whether it is possible to use phenol-formaldehyde (PF) resin modified using various amounts (0%, 5%, 10%, 15%, and 20%) of polymeric 4,4'-methylene diphenyl diisocyanate (pMDI) for this purpose. The need to optimize the addition of pMDI is particularly important due to health and environmental aspects and high price. Furthermore, the curing process of hybrid resins is still not fully explained, especially in the case of small loadings. Manufactured particleboards differed in the share of impregnated particles (50% and 100%). The mixture of potassium carbonate and urea was used as the impregnating solution. Based on the outcomes of hybrid resins properties, it was found that the addition of pMDI leads to the increase in solid content, pH, and viscosity of the mixtures, to the improvement in resin reactivity determined using differential scanning calorimetry and to the decrease in thermal stability in the cured state evaluated using thermogravimetric analysis. Moreover, particleboard property results have shown that using impregnated particles (both 50% and 100%) decreased the strength of manufactured boards bonded using neat PF resin. However, the introduction of pMDI allowed us to compensate for the negative impact of fire-retardant-treated wood and it was found that the optimal loading of pMDI for the board containing 50% of impregnated particles is 5% and for board made entirely of treated wood it is 10%.

Effect of Dipping in Hot Water and Chitosan and Vacuum Packaging on Storability of Two Persimmon cvs.

The purpose of this study was to examine the impact of different treatments on two cultivars of persimmon fruit, Diospyros kaki L. cvs. Fuyu and Hachiya. Specifically, the study aimed to investigate the effects of dipping the fruits in hot water at various temperatures (20°C as control, 40°C, and 50°C) for a duration of 5 minutes, as well as dipping them in chitosan solution at concentrations of 1% and 2% for 5 minutes. Additionally, the study explored the influence of two packaging methods, namely vacuum polyethylene packaging and non-vacuum polyethylene packaging. The impact of storing two cultivars of persimmon fruit in a cold room at a temperature of 1°C and relative humidity (RH) ranging from 80% to 90% for a duration of four months on their storage behavior was examined. Following the storage time, it was observed that Fuyu persimmon cultivar exhibited a notable reduction in fruit weight, whereas Hachiya persimmon fruits displayed significantly greater levels of total soluble solids and ascorbic acid content. The application of dipping treatments was found to effectively mitigate fruit weight loss. Notably, immersing persimmon fruit in hot water at a temperature of 40°C yielded a significant increase in the overall concentration of soluble solids. The implementation of vacuum packaging resulted in a decrease in fruit weight loss, while concurrently leading to an increase in the levels of carotene and ascorbic acid. The quality of persimmon fruit was maintained through the interaction of CVS, dipping treatments, and vacuum packaging.

Effects of Different Storage Temperatures and Methyl Jasmonate on Grape Quality and Antioxidant Activity

The aim of this study was to find out how different postharvest temperatures and MeJA treatments affected the quality of table grapes, their antioxidant properties, and the amount of hydrogen peroxide and malondialdehyde they contained. For the investigation, postharvest Shine Muscat table grapes were treated with low and high temperatures and MeJA at concentrations of 10 and 100 μmol/L. The results indicated that treating grape berries with MeJA at concentrations of 10 and 100 μmol/L effectively reduced weight loss and mitigated the increase in soluble solid content while also mitigating the decrease in berry firmness and titratable acidity. Consequently, this treatment preserved the sensory and nutritional qualities of the berries and extended their shelf life. Meanwhile, the application of MeJA at a concentration of 10 μmol/L demonstrated superior effectiveness compared to the 100 μmol/L concentration and resulted in a significant enhancement of antioxidant activities by increasing levels of superoxide dismutase, catalase, ascorbate peroxidase, and polyphenol oxidase. Furthermore, the levels of hydrogen peroxide and malondialdehyde in the samples increased for all treatments throughout the storage period. Nevertheless, the levels of hydrogen peroxide and malondialdehyde generation following MeJA treatment remained much lower compared to samples treated at room temperature and low temperature. Therefore, the postharvest application of MeJA at a concentration of 10 μmol/L could play a critical role as a stimulator of fruit quality as well as enhance physicochemical parameters and antioxidant activities for extending the shelf life of grapes during storage.

Fabrication and characterization of ZrO2(3Y)/Al2O3 micro-ceramic gears with high performance by vat photopolymerization 3D printing

To date, overcoming the trade-off between high solid loading and print accuracy and strength, achieving high-performance and fine ZrO2 micro-ceramic components through vat photopolymerization 3D printing remains challenging. In this study, the effects of dispersant, particle size and solid content on the dispersion, rheological behavior and stability of ZrO2 ceramic slurry were systematically studied, and complex, fine and high-performance ZrO2 micro-ceramic gears were successfully prepared. Then, the microstructure, mechanical properties, tribological properties and surface quality were evaluated. The results show that the rheological behavior of the slurry is the best when the optimal dispersant content is 3.5 wt%. With the increase of solid content, the sintering shrinkage of ZrO2(3Y)/Al2O3 ceramics decreased, while the relative density, compressive strength, flexural strength, fracture toughness and hardness increased. The prepared micro-ceramic gears not only have fine structure, but also have dense microstructure and good mechanical properties. The relative density, compressive strength, flexural strength, fracture toughness and hardness strength of ZrO2(3Y)/Al2O3 ceramics can reach 98.53 %, 1900 MPa, 648 MPa, 6.4 MPa × m1/2 and 13.40 GPa, respectively. In particular, this study couples the printing accuracy and strength with the solid load. By adjusting the relationship between the fixed load and the shrinkage rate, the printing of samples with different sizes is realized, which breaks through the accuracy limit of the printing equipment and provides a new idea for the preparation of micro-ceramic gears.

Potensi Biogas Dengan Pretreatment Substrat Kulit Kopi Menggunakan Campuran Rumen Sapi

Biogas is an alternative energy source to reduce the use of fossil fuels. This research aims to explore the potential production of biogas using pretreatment of coffee husk substrate, both biologically with civet dung and chemically with NaOH solution, and compare it with the process without pretreatment. The fermentation process is carried out by adding rumen microorganisms to each digester with variations in substrate composition and fermentation time for 35 days, with sampling times at 7, 14, 21, 28, and 35 days. Biogas testing is performed by measuring the methane (CH4) content and total solids (TS) in the substrate. The results of the research show that pretreatment of coffee husk substrate has a significant impact on biogas (CH4) production. Biological pretreatment with civet dung produced the highest methane gas, reaching 42.3724% on the 28th day of fermentation with a mixture of 50% coffee husk + 25% rumen + 25% water, while the process without pretreatment produced the lowest methane gas, at 6.38433% on the 7th day of fermentation. The total solids results indicate an increase and decrease in total solids content in the reactor with various treatments. The highest total solids result was obtained with biological pretreatment at 40.15%. This research indicates that biological pretreatment of coffee husk substrate with civet dung can increase biogas production efficiency, which can be a potential solution to reduce dependence on fossil energy sources and sustainably manage coffee husk waste.Keywords: Biogas, Pretreatment, Coffee Peel, Civet Dung, Rumen Microorganisms, Production Efficiency, NaOH Solution.

Design of novel Al-Mg-(Zn-Sc) alloys with enhanced mechanical properties and corrosion resistance

The novel Al-Mg-(Zn-Sc) alloys were fabricated using vacuum induction melting and argon-protected casting method. The effects of Zn and Sc on the microstructure evolution, mechanical properties and corrosion properties of the as-cast Al-Mg-(Zn-Sc) alloys were comparatively studied. The results show that the addition of 1.5 wt% Zn facilitates the evolution of coarsen β-Al3Mg2 phases into fine T-Mg32(Al, Zn)49 phases, enhancing the resistance to intergranular corrosion (IGC) of Al-5.5Mg-1.5Zn-0.4Sc (alloy 4) with a maximum corrosion depth of 133.4 µm. The addition of Zn also promotes Mg solid solution, resulting in a 13.7 % increase in Mg solid solution concentration in Al-5.5Mg-1.5Zn (alloy 3) compared to Al-5.5Mg (alloy 2). The addition of 0.4 wt% Sc leads to the formation of smaller (∼2 µm) Al3Sc particles with a larger volume fraction of 0.96 %, providing grain refinement and improved strength in the Al-Mg alloy. Furthermore, the joint addition of Zn and Sc elements reduces the grain size by 64.0 % compared to Al-5.0Mg (alloy 1) and increases the tensile strength by 33.5 %. Alloy 4 exhibits the greatest measured tensile strength of 343 MPa. The solid solution strengthening, grain boundary strengthening and precipitation strengthening contributions to alloy 4 are calculated at 76.8 MPa, 27.9 MPa and 66.6 MPa, respectively.

Effect of solid content on the piezoelectric properties of porous (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 ceramics

The influence of the solid content of porous (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 (BCZT) ceramics on the pore morphology and mechanical and piezoelectric properties was systematically investigated. The results show that with an increase in solid content, porosity and pore size decreased, and ceramic connectivity increased, leading to an increase in compressive strength. The best ferroelectric performance was achieved with an Ec of 2.40 kV/cm2 and a Pr of 2.01 μC/cm2 at a solid content of 30 vol%. When the solid content increased, the relative dielectric constant and the piezoelectric constant increased, which affected the piezoelectric energy harvesting performance. At a solid content of 20 vol%, g33 and FOM33 reached maxima of 43 × 10−3 Vm/N and 6.7 p.m.2/N, which were 2.40 times and 1.8 times those of the other solid contents, respectively. This work provides new ideas for the design of porous piezoelectric ceramics and the improvement of their piezoelectric properties for future piezoelectric energy harvesting applications.

The synthesis of high-strength monolithic Al2O3-SiO2 aerogels through increased solid content and high-temperature calcination

High-strength Al2O3-SiO2 aerogels were synthesized by simultaneously increasing the solid content and high-temperature calcination. The effects of solid content and high-temperature calcination on mechanical properties, thermal conductivity, and microstructure of Al2O3-SiO2 aerogels were studied. The increase in solid content can improve the mechanical properties of aerogels. High-temperature calcination can further improve mechanical properties and reduce thermal conductivity. Finally, we fabricated a high-strength monolithic Al2O3-SiO2 aerogel with a high Young’s modulus of 127.45 MPa, room temperature thermal conductivity of 29.15 mW·m−1·K−1, and density of 252 mg·cm−3. This work is significant to the adhibition of Al2O3-SiO2 aerogels as high-strength thermal insulation materials.

CFD simulation of co-precipitation synthesizing nanofibrous γ-alumina precursor in serial membrane dispersion microreactors

Herein, a partitioned nucleation and growth model is constructed for the CFD-PBM coupled simulations of pseudo-boehmite (PB), that is, γ-alumina precursor co-precipitation synthesis in the equipment with two serial membrane dispersion microreactors and a circulating continuous phase. The flow condition inside the microreactor is analyzed, and the spiral flow is found to considerably improve the mixing efficiency. Simultaneously, as the phase ratio increases to 54, the average length-diameter ratio of PB nanofibers with an average diameter of 2.3 nm increases to 69, and growth is more dominant than the nucleation. Moreover, the increase of solid content in the continuous phase is dominated by nucleation for the first 10 min, followed by growth and augmentation in the number of nanofibers during 10–60 min, and an increase in the number of nanofibers beyond 60 min. Finally, the simulation results have minor errors by contrast with the experimental data from our previous work.

Hydrocarbon residue in a Danish chalk reservoir and its effects on CO2 injectivity

Depleted oil and gas chalk reservoirs in the Danish North Sea are considered for Carbon Capture and Storage (CCS) as part of Denmark's strategy to reduce CO2 emissions. While these reservoirs are well understood after decades of hydrocarbon production, the interaction between CO2 and hydrocarbon residues (HCRs) is less understood and pose a major challenge. This study investigates the effects of supercritical CO2 (sc-CO2) injection on HCRs in a core plug from the Upper Cretaceous chalk reservoir of the Halfdan Field, Danish North Sea, after sc-CO2 flooding for nine days in near reservoir conditions (85 °C and 27.6 MPa). The HCRs from before and after the sc-CO2 flooding were analyzed using Extended Slow Heating (ESH®) pyrolysis, Thermal Desorption Pyrolysis Gas Chromatography-Mass Spectrometry (TD-Py-GC/MS), and organic petrography methods. Results indicate that sc-CO2 can effectively mobilize and put into solution all lighter hydrocarbon fractions, leaving behind heavy immiscible asphaltene-rich hydrocarbons and solid bitumen. In the post-CO2 flooding sample, the asphaltene-rich, immobile oil and solid bitumen aggregates were physically trapped at various points, though primarily at the outlet section due to a sudden change in pressure. The results indicate pressure differences cause up to 10.5% of total rock volume precipitation of pure solid bitumen, which can significantly alter the ongoing flow of sc-CO2 in the reservoir. The HCRs also show an increasing proportion the heaviest, solid bitumen fraction from the inlet of sc-CO2 injection to the outlet of the plug. The increase in solid bitumen content away from the sc-CO2 inlet point is suggested to be caused by selective solubility together with imbibition of hydrocarbons within the flowing sc-CO2 phase, thereby changing the bulk polarity and hence the solubility - here referred to as the Avalanche Effect.

Rheology of Suspensions of Solid Particles in Liquids Thickened by Starch Nanoparticles

The rheology of suspensions of solid particles in aqueous matrix liquids thickened by starch nanoparticles (SNP) was investigated. The SNP concentration varied from 9.89 to 34.60 wt% based on the aqueous matrix phase. The solids concentration of suspensions varied from 0 to 47 wt% (0 to 56 vol%). The suspensions at any given SNP concentration were generally Newtonian at low solids concentrations. At high solids concentrations, the suspensions were non-Newtonian shear-thinning. With the increase in the SNP concentration, the suspensions become non-Newtonian at a lower solids concentration. The rheological behavior of non-Newtonian suspensions could be described adequately with a power-law model. The consistency index of the suspension increased with the increase in solids concentration of the suspension at any given SNP concentration. The flow behavior index of suspensions was well below unity at high solids concentrations, indicating non-Newtonian shear-thinning behavior. The value of the flow behavior index decreased with the increase in solids concentration indicating an enhancement of shear-thinning in suspensions. The experimental viscosity and consistency data for Newtonian and non-Newtonian suspensions showed good agreement with the predictions of the Pal viscosity model for suspensions.