The improvement of different hydrocolloids (hydroxypropylmethyl cellulose (HPMC), carboxymethylcellulose (CMC), xanthan gum (XG) and apple pectin (AP)) and proteins (egg white protein (EWP), soy ...protein isolate (SPI), total egg protein (TEP) and whey protein concentrate (WPC)) on the quality of sweet potato-wheat bread (SPWB) from 50% sweet potato flour (SPF) and 50% wheat flour (WF) were investigated. The changes of thermomechanical behaviour, rheological properties, water mobility of dough and in vitro starch digestibility of SPWB were evaluated. XG incorporation significantly increased the peak viscosity (from 259.50 to 1300.67 RVU) and water absorption (from 56.89% to 63.45%) of sweet potato-wheat flour. Dough incorporated with XG showed a homogeneous network structure with immense protein cross-linkages. SPWB with XG exhibited higher specific volume (2.09 ml/g), lower hardness (27.95 N), and expected glycemic index (35.87) as compared to other formulas. XG supplementation could be applied to produce novel SPWB with high quality.
•Hydrocolloids and proteins were used for sweet potato-wheat bread (SPWB) making.•Xanthan gum (XG) increased water absorption capacity of flour, followed by HPMC.•Dough incorporated with XG showed a homogeneous network structure.•SPWB with XG showed lower expected glycemic index, followed by SPI, AP, WP and TEP.•XG supplementation could produce novel SPWB with high quality.
In this study, the effects of Mesona chinensis polysaccharide (MCP) on the pasting, thermal, rheological, and textural properties of wheat starch were investigated. Rapid viscosity analysis results ...showed that MCP protects the integrity of starch granules at low concentration in the early stage of pasting. The gelatinization temperature of wheat starch–MCP gels was markedly increased with the increase in polysaccharide concentration, whereas gelatinization enthalpy (ΔHgel) decreased. Rheological analysis showed that the starch:MCP = 8.5:1.5 system exhibited a strong thixotropic property and the highest G′ and G″ among the other systems. The same results were observed in the textural experiment, indicating the existence of strong intermolecular interactions between starch granules and MCP. These results indicated that MCP can improve the thermal stability in the early stage of pasting and enhance the rheological properties of wheat starch.
•MCP promoted the thermal property of wheat starch at the early stage of pasting.•The roles of MCP were different on apparent characters depend on the starch concentration.•Thixotropy property of wheat starch-MCP with different ratios followed in this order: 8.5:1.5 > 10.0:0 > 8.0:2.0.
Microstructural changes in ceria-based suspensions at different pH values and corresponding rheological and drying properties were correlated. Ceria-based suspensions were classified into four zones ...based on their pH values. Well-dispersed or aggregated states of ceria particles in suspensions were mainly discerned by the magnitude of zeta-potential with pH variations and additional condensation reaction at relatively high pH. Suspensions with well-dispersed particles in a particular pH range exhibited transition between shear-thinning and Newtonian behavior along the shear rate and weak thixotropic features, whereas suspensions with agglomerated particles in different pH ranges showed significant shear-thinning and thixotropic behaviors with shear rate. The motion of particles within suspension droplets in each zone was quantified in terms of autocorrelation functions during drying using multi-speckle diffusing wave spectroscopy. Suspension droplets with well-dispersed particles showed conspicuous coffee-ring patterns compared to those with aggregated particles, owing to the rapid Brownian motion of well-dispersed particles.
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•The dispersion state of ceria particles depends on the pH condition.•A densely packed structure at high pH originates from the condensation reaction•Rheological properties and drying characteristics are correlated with the microstructures.
High-volume fly ash (FA) cement presented a slow setting and lower early compressive strength, restricting the utilization in cemented paste backfill (CPB). The present work investigated the ...feasibility of using metakaolin with various particle sizes and content to modify the properties of FA cement. Reaction kinetics, rheological properties, setting time, compressive strength, hydration products, and the CPB samples' microstructure were thoroughly studied. The results showed that 5 wt% of super-fine metakaolin (SMK) could strongly promote the binder hydration, leading to the formation of a more compact matrix with higher early compressive strength. The 3 d-compressive strength of the CPB samples was increased by around 216% after replaced by 5 wt% of SMK. Besides, the binder doped with 5 wt% SMK showed better environmental and cost performance.
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•Adding 5 wt% of SMK increased the 3 d- strength of the CPB samples by 216%.•SMK promoted the hydration and refined the pore structure of CPB.•The addition of MK decreased the flowability of the fresh CPB.•The presence of MK favored the formation of more AFm phases.
Effects of agar on the rheological property and heat stability of casein micelle gels induced by rennet were investigated. The interactions between casein micelle and agar were investigated. ...Electrostatic interactions between casein micelle and agar were not observed. The movement of agar characteristic bonds indicated the hydrogen bond interaction existed in the casein micelle/agar mixture. The addition of agar promoted the casein micelles aggregation and decreased the rennet coagulation time (RCT) and the storage modulus (G'). The strip-like network microstructure changed into a sheet-like network after the addition of agar. The composite gels were present as a bicontinuous phase structure. The agar and protein were both present as continuous phases. The addition of 0.5% agar increased the water holding capacity (WHC) from 63.30% to 92.44% and decreased the gel hardness from 73.41 g to 60.57 g. The protein digestion rate of gels increased after agar addition during gastric digestion. The WHC increased from 35.20% to 83.56% and the microstructure of gels improved by the addition of 0.5% agar after heating at 80 °C for 30 min. In conclusion, the WHC and thermal stability of the gels improved after the addition of agar.
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●The hydrogen bond interaction existed in the casein micelle/agar mixture.●The addition of agar decreased the rennet coagulation time and the storage modulus.●The composite gels had a bicontinuous phase structure.●The addition of agar improved the thermal stability of the gels.
The identification of styrene‐butadiene‐styrene (SBS) content is crucial in engineering applications since the key to assessing the performance of aged‐modified asphalt is the SBS content. Six types ...of modified asphalts with various SBS contents were prepared, and physical, rheological, and Fourier‐transform infrared spectroscopy (FTIR) tests were conducted. The fitting relationship between aged‐modified asphalt indexes and SBS content was established, and the three methods' accuracy, simplicity, and efficiency were compared and analyzed. The results showed that the fitting relationship between SBS content and viscosity could exceed 0.83 after aging. However, the linear and quadratic fittings deviated from the measured values, and the softening point had no apparent law with the SBS content. The rheological index method significantly correlated with SBS content and is highly automated. However, FTIR was established based on the direct detection of SBS characteristic peaks compared with the physical and rheological indexes methods. It could directly reflect the SBS content and was not easily disturbed by SBS substitutes. In addition, after long‐term aging, the linear relationship between SBS characteristic peak index, A966/A811, and SBS content could exceed 0.97. The FTIR test exhibited high accuracy and fast detection speed and is the best detection method for SBS content.
Detection of polymer content in SBS modified asphalt after aging.
•Increased nitrogen level reduced amylose content but increased ash content.•All the common buckwheat starches showed typical A-type XRD pattern.•High relative crystallinity were observed under high ...nitrogen level.•Samples had higher gelatinization enthalpy with increasing nitrogen level.•Nitrogen fertilizer led to a decrease in the storage modulus and loss modulus.
Nitrogen is an essential element for the yield and quality of grain. In this study, the structural and physicochemical properties of two common buckwheat varieties under four nitrogen levels (0, 90, 180, 270 kg N ha−1) at one location in two years were investigated. With increasing nitrogen level, the contents of moisture and amylose decreased but the contents of ash and crude protein increased. Excessive nitrogen application significantly increased the granule size, but reduced the light transmittance, water solubility, swelling power, absorption of water and oil. All the samples showed a typical A – type pattern, while high relative crystallinity and low order degree were observed under high nitrogen level. The samples under high nitrogen level had lower textural properties, pasting properties and rheological properties but higher pasting temperature and gelatinization enthalpy. These results indicated that nitrogen fertilizer significantly affected the structural and physicochemical properties of common buckwheat starch.
Many emerging materials, such as ultrastable glasses
of interest for phone displays and OLED television screens, owe their properties to a gradient of enhanced mobility at the surface of ...glass-forming liquids. The discovery of this surface mobility enhancement
has reshaped our understanding of the behaviour of glass formers and of how to fashion them into improved materials. In polymeric glasses, these interfacial modifications are complicated by the existence of a second length scale-the size of the polymer chain-as well as the length scale of the interfacial mobility gradient
. Here we present simulations, theory and time-resolved surface nano-creep experiments to reveal that this two-scale nature of glassy polymer surfaces drives the emergence of a transient rubbery, entangled-like surface behaviour even in polymers comprised of short, subentangled chains. We find that this effect emerges from superposed gradients in segmental dynamics and chain conformational statistics. The lifetime of this rubbery behaviour, which will have broad implications in constraining surface relaxations central to applications including tribology, adhesion, and surface healing of polymeric glasses, extends as the material is cooled. The surface layers suffer a general breakdown in time-temperature superposition (TTS), a fundamental tenet of polymer physics and rheology. This finding may require a reevaluation of strategies for the prediction of long-time properties in polymeric glasses with high interfacial areas. We expect that this interfacial transient elastomer effect and TTS breakdown should normally occur in macromolecular systems ranging from nanocomposites to thin films, where interfaces dominate material properties
.
In this paper, it was found that with the addition of sodium dodecyl sulfate (SDS, a hydrophilic surfactant) and oleic acid (OA, a lipophilic surfactant) in a solvent with a proper composition ratio, ...a stable gel could be obtained via a simple ultrasonic treatment. The synergistic gelation of OA–SDS was verified in a series of solvents with different polarities, such as white oil (WO), LB-2000, n-hexane, polyalphaolefin (PAO10), and deionized water. The Fourier transform infrared (FTIR) analysis confirms that the gelation of OA–SDS is highly related to the ion exchange reaction between them. However, the xerogel of OA–SDS gelator in deionized water and WO (OSW) exhibited remarkably different morphologies, indicating that the gelation is based on different molecular assembly processes, which is governed by the orientation of the two surfactant molecules in liquid media. Further characterizations of OSW gel presented that the synergistic effect between OA and SDS not only existed in gelation, but also in enhancing the mechanical and thermal stability of WO, and endowing the OSW gel with reliable friction reduction and antiwear performances under variable working conditions. Subsequently, the lubrication mechanism was proposed based on rheological analysis and the morphological and compositional analysis of wear surfaces. This study provides a novel idea for the molecular design of lubricating gelators with wide adaptability to solvent polarity and working conditions.
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•The synergistic effect of OA and SDS on gelation and lubrication was presented.•The OA–SDS exhibits excellent gelling capacity in solvents of different polarities.•OA–SDS gelator in water and white oil have different gelling mechanisms.•OA–SDS gelator greatly improved the tribological properties of white oil.
