Dynamic Shear Rheology Research Articles

From Block to Shred: Understanding the Factors Influencing Shreddability of Mozzarella Cheese

Mozzarella cheese (MC) is widely used for pizza applications, and it is generally shredded either in conversion plants or in pizzerias. The shreddability of MC is influenced by a variety of factors and it is critical to understand how different Mozzarella cheese types and storage conditions (temperature and age) affect this property. Three batches each of 3 types of MC (low-moisture Mozzarella (LMM), low-moisture part-skim Mozzarella (LMPS), and reduced fat Mozzarella (RFM)) representing 3 different fat levels were procured directly from a commercial manufacturer and stored at 2 different temperatures (1.67 and 4.44°C) and evaluated for shreddability at 2- and 3-weeks storage. Shreddability parameters such as stiction (peak force) and work of grating were significantly affected (P <0.05) by fat content and storage time, while the weight of the shred obtained after each cycle was significantly affected (P <0.05) by fat content and storage temperature. Along with shreddability, other tests such as texture profile analysis (TPA), wire cutting, stretchability, and dynamic shear rheology (DSR) were performed to understand their relationship with shreddability. Textural parameters were significantly affected (P <0.05) by fat content and storage time while wire-cutting parameters were significantly affected by fat content, storage time, and temperature. Stretchability and dynamic shear rheology parameters were significantly affected by fat content followed by storage time and temperature. Further shreddability parameters such as stiction and work of shear had a positive significant correlation while the weight of shreds had a negative significant correlation with unmelt (TPA) and melt parameters (stretchability and DSR). Overall, fat content had the greatest effect on shreddability followed by storage time and temperature. Considering the high correlation of shreddability with other textural parameters, textural parameters can be used to predict shreddability of MC.

Effects of bonding enhancers on shear stress and bonding strength of modified asphalt binders under different aging and moisture conditions

Insufficient bonding within pavement material causes widespread propagation of traffic-induced stresses, leading to accelerated damage accumulation and significant reduction in the service life of flexible pavements. This research aimed to examine the effects of using bonding enhancers, specifically Polyalkylene Glycol-based (PLG) and Alkylamines-based (ALM), on modified asphalt binders to improve the bonding characteristics. These additives were utilized at different concentration levels, i.e., 0.5 % and 1.0 %, based on the mass of asphalt binders, with the aim of enhancing the bonding performance between the materials within the asphalt mixture composite. The effectiveness of the modified asphalt binders was compared to the conventional ones through laboratory tests, which included shear-compression and pullout tests. These tests were conducted to assess the bonding performance of the modified asphalt binders by preparing different sets of sandwich samples using concrete cube substrates. A sodium carbonate solution was used as a medium to accelerate the effect of moisture damage on samples during the conditioning process. Additionally, the bonding performance of the asphalt binders was evaluated through a series of pullout and shear-compression tests under designated moisture and aging conditions. The dynamic shear rheological (DSR) test results of Rolling Thin Film Oven (RTFO) and Pressure Aging Vessel (PAV)-aged binders incorporating bonding enhancers showed superior resistance to rutting and fatigue failure. Significant improvements in stress and shear strength were observed under moisture and aging conditions, highlighting improvements in the bonding performance of the modified asphalt binders. The incorporation of additives has positively contributed to the pavement performance, despite only a modest increase in bonding performance, tensile strength, and shear stress resistance.

Towards the high RAP dosage obtained by refined processing influence on comprehensive performance of recycled asphalt mixture

The severe agglomeration of Reclaimed Asphalt Pavement (RAP) particles not only leads to high gradation variability during recycling, but also impedes the miscibility between new-old binders. This phenomenon imposes significant limitations on maximizing the utilization of RAP with high content and value. This paper first realized the effective separation of asphalt milling material by the self-developed RAP refined processing equipment to obtain coarse RAP with low binder content and fine RAP with high binder content. The fine RAP with high binder content underwent a deep rejuvenation process, and the recovery efficiency of the asphalt mortar was evaluated by CT scanning test, microscope observation test, and dynamic shear rheology test. Moreover, to investigate the strength formation characteristics of recycled asphalt mixtures with high RAP content, specific tests including wheel tracking test, three-point bending test, Hamburg Wheel Tracking test, dynamic modulus test, and two-point bending fatigue test, were conducted. By using the refined processing equipment, the asphalt film on the RAP can be precisely removed, thereby addressing the issue of aged binder agglomeration. In the coarse RAP with low binder content, the binder content was reduced to 1.48 %, allowing it to be used as a direct substitute for new aggregate, whereas the binder content of fine RAP exceeded 10 %. It was found that the direct incorporation of unrefined RAP enhanced the high-temperature stability and dynamic modulus of recycled asphalt mixture, but impacted their low-temperature cracking resistance, moisture stability, and fatigue performance. After refined processing and differentiated recycling design, the agglomeration of aged binder was reduced and the miscibility of new-old binders was improved, effectively enhancing the comprehensive performance of the recycled asphalt mixture. It should be noted that the mixing homogeneity and miscibility decrease as the RAP content exceeds 75 %, resulting in the reduction of moisture stability, cracking resistance, and fatigue performance of recycled asphalt mixture.

Self-Healable Hydrogels from Vegetable Oil: Preparation, Mechanism, and Applications.

Hydrogels are indispensable for a variety of applications. Conventional biomaterial-based hydrogels, typically made from proteins or polysaccharides, often suffer from high costs, poor mechanical properties, and limited chemical functionality for modification. In this work, we present a novel hydrogel developed from modified castor oil, which is a renewable and cost-effective resource. Castor oil-based oligomer (CG) was synthesized using glycidyl methacrylate and triethylamine via ring-opening polymerization. The oligomer formed a gel only with Cu2+ ions among the various systematically studied metal ions. Comprehensive density functional theory calculations, atoms in molecules analysis, and steady and dynamic shear rheology were conducted to investigate the metal-binding sites and metal-oligomer interactions as well as the self-healing and viscoelastic properties of the oil-based hydrogels. The hydrogel exhibited 94% self-healing efficiency and performed as a recyclable rhodamine B dye adsorbent (73-90%). This innovative approach offers a novel, cost-effective, and sustainable alternative to traditional hydrogels, paving the way for advanced applications.

Electrochemical Exfoliation of Graphene and Formation of its Copolyamide 6/66 Nanocomposites by Wet Phase Inversion and Injection Molding

AbstractElectrochemically exfoliated graphene (EEG) is compounded with copolyamide 6/66 (PA6/66) to investigate the influence of the carbonaceous filler material on the thermal, rheological, and mechanical properties of the composite. Toward that end, the environmentally friendly electrochemical exfoliation in aqueous solution is further developed to furnish graphene in large quantities. Separating the exfoliation process from the incorporation into the polymer matrix by wet phase inversion (WPI) allowed in‐depth characterization of the EEG by scanning electron microscopy (SEM), atomic force microscopy (AFM), and Raman spectroscopy. The crystallinity of copolyamide 6/66‐EEG is significantly changed, as revealed by differential scanning calorimetry (DSC). Likewise, the new composite materials exhibit different flow properties, as well as increased mechanical reinforcement with additive concentration. This is proven by dynamic shear rheology and three‐point stress tests compared to the neat polymer.

Mechanistic Study on the Optimization of Asphalt-Based Material Properties by Physicochemical Interaction and Synergistic Modification of Molecular Structure

In order to investigate the relationship between the molecular structure of fibers and the differences in physicochemical interactions between fibers and asphalt on the performance of fiber-modified asphalt, this paper chose two types of fibers with different chemical structures: straw fiber and polyester fiber. First, the differences in molecular interactions between the two fibers and asphalt were explored using molecular dynamics, then the differences in the adsorption capacity of the two fibers on asphalt components were tested by attenuated total reflection infrared spectroscopy experiments, and finally, the differences in the rheological properties of the two fiber-modified asphalts were tested by dynamic shear rheology and low-temperature creep experiments. The molecular dynamics simulation findings reveal that polyester fibers may intersperse into asphalt molecules and interact with them via structures such as aromatic rings, whereas straw fibers are merely adsorbed on the asphalt’s surface. Straw fibers and asphalt exhibit hydrogen bonding, whereas polyester fibers and asphalt display van der Waals interactions. The results of attenuated total reflectance infrared spectroscopy indicated that polyester fiber absorbed asphalt components better than straw fiber. The rheological tests revealed that the polyester fiber had the highest complex shear modulus in the temperature range of 46–82 °C, and at 64 °C, the phase angle was 4.289° lower than that of the straw fiber-treated bitumen. Polyester fiber-modified asphalt had a 32.48%, 15.72%, and 6.09% lower creep modulus than straw fiber-modified asphalt at three low-temperature conditions: −6 °C, −12 °C, and −18 °C. It is clear that fibers with aromatic rings as a chemical structure outperform lignin-based fibers in terms of improving asphalt characteristics. The research findings can serve as a theoretical foundation for the selection of fibers to produce fiber-modified asphalt.

Synergistic effects of buton rock asphalt and BBOEA on the enhanced temperature resistance and flexibility of asphalt

To improve the toughness of transportation infrastructure and develop asphalt composite materials with both elasticity and toughness, this paper prepared Buton rock asphalt (BRA)/Bis[2-(2-butoxyethoxy)ethyl] adipate BBOEA composite modified asphalt. The evolution of high and low-temperature performance of the composite modified asphalt was explored through key asphalt indicators, dynamic shear rheology, and bending beam rheometer (BBR) tests. The performance improvement mechanism of the asphalt was investigated using Fourier transform infrared spectroscopy (FTIR). The addition of Buton rock asphalt effectively improved the high-temperature performance of the asphalt, raising the high-temperature PG grade from 64 to 70 and enhancing resistance to permanent deformation. The inclusion of 1.5 % BBOEA further enhanced low-temperature performance, reducing the stiffness modulus of BRA modified asphalt from 365 MPa to 260 MPa, a decrease of 26.9 %. This improvement is attributed to the polar adipate functional groups in BBOEA, which promote hydrogen bonding and dipole–dipole interactions with polar groups in the resins, reducing micelle size and asphalt rigidity. With the high-temperature performance remaining robust and low-temperature flexibility and strain relaxation greatly improved, the optimal BBOEA content is recommended at 1.5 % of the asphalt mass.

Synthesis of a novel bio-based curing agent and the curing behavior of the corresponding epoxy asphalt system

Traditional epoxy asphalt is made from petroleum resources. However, petroleum-based materials may cause environmental pollution and are not renewable. In this study, a bio-based curing agent MYM was synthesized from Maleic anhydride and Myrcene. The cured epoxy EP/MYM with the weight ratio of 1:1 were prepared. When preparing the modified asphalt, carboxyl-terminated liquid nitrile butadiene rubber (CTBN) was incorporated into the EP/MYM system to obtain the EP/MYM/CTBN modified asphalt system (referred to EMC epoxy asphalt). Firstly, the chemical structure of MYM was characterized using Fourier transform infrared spectroscopy (FTIR). Secondly, the mechanical properties and thermal stability of the cured EP/MYM were investigated by tensile test and thermogravimetric analysis (TG). Thirdly, the novel EMC epoxy asphalt was prepared and its composition was optimized. The curing behavior of the EMC epoxy asphalt was investigated by differential scanning calorimetry (DSC). And the time-temperature-transition diagrams (TTT diagrams) were plotted to determine the optimal curing process. Then the surface micro-morphology of EMC epoxy asphalt was investigated by atomic force microscopy (AFM). Finally, the high-temperature viscoelastic properties of EMC epoxy asphalt were investigated using dynamic shear rheology (DSR) tests. The results showed that EP/MYM has better mechanical strength and more excellent flexibility than those of EP/MTHPA and EP/MHHPA. The weight ratio of EP:MYM:CTBN was 10:8:1.5, and the optimal amount of diluent was 8 % of the total weight of the modifier. The semi-empirical kinetic modes of curing reaction were used to plot the TTT diagram of EMC epoxy asphalt, thus determining its curing technique as 120℃/2 h+160℃/3 h. The cured EMC epoxy asphalt showed uniform alternation of light and dark areas in the AFM images, indicating good compatibility and stability. The high-temperature deformation resistance of EMC epoxy asphalt was significantly improved compared to the base asphalt. The novel epoxy asphalt system prepared in this research provides a new route for the development of echo-friendly epoxy asphalt.

Development of novel protein-rich foods: Studies of composite hydrogels formed from potato proteins and gellan gums with different degrees of acylation

The textural attributes of mixed hydrogels formed from potato protein (PP) and gellan gum (GG) were examined for their potential application as novel protein-rich foods (NPFs). Initially, the properties of gels formed by the individual biopolymers were characterized using dynamic shear rheology, compression testing, and confocal fluorescence microscopy. Rheological analysis revealed that PP dispersions formed irreversible heat-set gels, whereas GG formed reversible cold-set gels at lower temperatures. The effects of adding PP to high acyl gellan gum (HA-GG) or low acyl gellan gum (LA-GG) solutions on the microstructure and rheology of the mixed gels formed were then examined. The PP/LA-GG composite gels had a highly heterogeneous microstructure consisting of protein-rich and polysaccharide-rich regions. In contrast, the PP/HA-GG composite gels had a more uniform microstructure. Interestingly, the incorporation of the PP weakened the PP/LA-GG composite gels (antagonism) but strengthened the PP/HA-GG composite gels (synergism), which was mainly attributed to their different impacts on gel microstructure. This study shows that semi-solid plant protein-dietary fiber composites can be formed with a variety of textural attributes by altering the nature and concentration of biopolymers used to formulate them. These mixed gels may be useful for the creation of NPFs. This study also highlights the complexity of the interactions between different food biopolymers and their impacts on food properties, highlighting the need for further research on understanding structure-function relationships in multicomponent biopolymer materials.

Development and Characterization of Hybrid Meat Analogs from Whey Protein-Mushroom Composite Hydrogels.

There is a need to reduce the proportion of animal-derived food products in the human diet for sustainability and environmental reasons. However, it is also important that a transition away from animal-derived foods does not lead to any adverse nutritional effects. In this study, the potential of blending whey protein isolate (WPI) with either shiitake mushroom (SM) or oyster mushroom (OM) to create hybrid foods with enhanced nutritional and physicochemical properties was investigated. The impact of OM or SM addition on the formation, microstructure, and physicochemical attributes of heat-set whey protein gels was therefore examined. The mushroom powders were used because they have relatively high levels of vitamins, minerals, phytochemicals, and dietary fibers, which may provide nutritional benefits, whereas the WPI was used to provide protein and good thermal gelation properties. A variety of analytical methods were used to characterize the structural and physicochemical properties of the WPI-mushroom hybrids, including confocal microscopy, particle electrophoresis, light scattering, proximate analysis, differential scanning calorimetry, thermogravimetric analysis, dynamic shear rheology, textural profile analysis, and colorimetry. The charge on whey proteins and mushroom particles went from positive to negative when the pH was raised from 3 to 9, but whey protein had a higher isoelectric point and charge magnitude. OM slightly increased the thermal stability of WPI, but SM had little effect. Both mushroom types decreased the lightness and increased the brownness of the whey protein gels. The addition of the mushroom powders also decreased the hardness and Young's modulus of the whey protein gels, which may be because the mushroom particles acted as soft fillers. This study provides valuable insights into the formation of hybrid whey protein-mushroom products that have desirable physiochemical and nutritional attributes.

The Rejuvenation Effect of Bio-Oils on Long-Term Aged Asphalt.

Generally, rejuvenators are used to supply missing components of aged asphalt, reverse the aging process, and are widely used in asphalt maintenance and recycling. However, compared with traditional rejuvenators, bio-oil rejuvenators are environmentally friendly, economical and efficient. This study looks into the effect of the three different bio-oils, namely sunflower oil, soybean oil, and palm oil, on the physical properties, rheological properties and chemical components of aged asphalt at different dosages. The asphalt physical properties and Dynamic Shear Rheological (DSR) test results show that with the increase in bio-oil, the physical properties and rheological properties of rejuvenated asphalt are close to those of virgin asphalt, but the high-temperature rutting resistance needs to be further improved. The results of Fourier Transform Infrared Spectroscopy (FTIR) show that the carbonyl and sulfoxide indices of rejuvenated asphalt are much lower than those of aged asphalt. Moreover, the rejuvenation efficiency of aged asphalt mixed with sunflower oil is better than that with soybean oil and palm oil at the same dosage.

Mechanochemical preparation and performance evaluations of bitumen-used waste polypropylene modifiers

The value-added recycling of waste polypropylene (PP) as asphalt modifiers has been a popular research topic in recent years, but high blending temperatures and asphalt smoke emissions are difficult issues that have not been solved. Therefore, this study innovatively used phthalic anhydride (PA) and catalysts (NHPI or BPO) to mechanochemically turn waste PP into different reaction products as bitumen-use PP modifiers (PPM(N) & PPM(B)). To well understand the physicochemical characteristics of PPMs, thermogravimetric analysis, torque rheology, and scanning electron microscopy were adopted and analyzed. Furthermore, the penetration, softening point, viscosity, storage stability, and dynamic shear rheology (DSR) tests were also carried out to study the performance differences of their PP modified asphalt (PPMA(N) & PPMA(B)). The main results showed that the PPM(N) continues being degraded with PA, but BPO-degraded PP conversely gets chemical connections with PA. With the effects of NHPI and BPO, all PPMs can improve the deformation resistance of virgin bitumen, even at higher temperatures, but as the PA content increases, this performance will gradually deteriorate for PPMA(N) and shows a slight improvement for PPMA(B). The appropriate use of PA can decrease the mixing temperature of PPM(N) with virgin bitumen and improve the storage stability of PPMA binders, and will not significantly sacrifice the resistances of its PPMA(N) to deformation, while with the addition of PA, the mixing temperatures of PPM(B) and virgin bitumen will not be decreased as expected and the resistances of PPMA(B) to deformation remain unchanged. Overall, the proposed mechanochemical method can work out to well address the high-quality recycling and reuse issue of waste PP for its large-scale application in asphalt pavement.

Steady and dynamic shear rheology of aqueous solutions of quince seed gum combinations with locust bean or xanthan gums

This study presents the rheological properties of quince seed gum (Q) solution in comparison with xanthan gum (X) and locust bean gums (L) and the polymeric interactions of different ratios of Q:X and Q:L blends (1:1, 1:3 and 3:1). Q exhibits greater and stronger elastic properties than X and L. The frequency and temperature stability of Q and X are both higher than that of L. The viscoelastic properties of Q:X and Q:L solutions were found to be higher than those of the individual solutions. The higher polymer entanglements observed in Q:L blends resulted in enhanced synergistic interactions and thixotropy compared to Q:X. 3QX exhibited an enhanced elastic structure, but the best synergism was observed for 3QL due to the establishment of a stronger intermolecular bond for gelling. The lower tan δ observed with increasing Q indicate a Q-induced synergistic interaction with L. At all temperatures, 3QL showed the highest thixotropy. The combination of Q and L resulted in the formation of a true gel, with the higher gel strength being observed for QL and 3QL. This study shows that Q:L and Q:X combinations can yield desired flow properties. In particular, L provides a firmer gel network with Q.

Synergy of devulcanized rubber and rock asphalt for asphalt modification

Rock asphalt (RA) has gradually been recognized as a green and efficient asphalt modifier. However, the weakness of low-temperature performance and fatigue resistance for RA modified asphalt limited its application and popularization in asphalt pavement. To overcome the above shortcomings, this study aimed to synergistically apply devulcanized rubber powder (DRP) with American rock asphalt (ARA) for asphalt modification. Multiple experiments such as dynamic shear rheology (DSR) and bending beam rheology (BBR) were conducted to evaluate the rheological properties and road performance of composite modified asphalt (CMA). Cigar tube test (CTT) was applied to assess storage stability of CMA. In addition, Fourier transform infrared spectrometer (FTIR) and microscopic test (MT) were used to investigate the modification mechanisms. The results showed that CMA modified by DRP and ARA exhibited comparable storage stability, low-temperature performance and rutting resistance as SBS modified asphalt. ARA tended to cause aging problems of asphalt, but the addition of DRP effectively improved the aging resistance performance of modified binder blends, especially long-term aging resistance. The mixing of DRP, ARA and base asphalt is a physical process without chemical reactions. Even though the ash in ARA slightly lowered its storage stability, it significantly improved dispersion and homogenous interface of DRP in asphalt.

Investigation of the Properties of High-Viscosity Modified Asphalt Binder under Hygrothermal Environments.

High-viscosity modified asphalt binder (HVMA) is used widely as a polymer-modified binder in porous asphalt pavement because it can improve the cohesiveness of the asphalt mixture. However, because of the high voidage in the mixture, HVMA is vulnerable to aging induced by temperature, oxygen, water, sunlight, and other climatic conditions, which degrades the performance of pavement. The properties of asphalt binder are affected adversely by the effects of hygrothermal environments in megathermal and rainy areas. Therefore, it is essential to study the aging characteristics of HVMA under the influence of hygrothermal environments to promote its application as a high-viscosity modifier. A hygrothermal cycle aging test (HCAT) was designed to simulate the aging of HVMA when rainwater was kept inside of the pavement after rainfall in megathermal areas. One kind of base bitumen and three kinds of HVMA (referred to as SBS, A, and B, respectively) were selected in this study. Short-term aging tests, hygrothermal cycling aging tests, and long-term aging tests were performed on the base bitumen and three kinds of modified asphalt binder. Fourier-transform infrared spectroscopy (FTIR), thermo-gravimetric analysis (TGA), and dynamic shear rheological (DSR) tests were used to evaluate the properties of the binders on the micro and macro scales. By comparing the index variations of the four binders before and after aging, the effects of the hygrothermal environment on the properties of HVMA were studied. It was found that the effects of the hygrothermal environment expedited the decomposition of the polymer and the formation of carbonyl groups compared with the TFOT and PAV test, which TGA confirmed further. Moreover, the thermal stability of the samples was improved after HCAT. In addition, the master curves of the complex modulus showed that hygrothermal cycles made the high-temperature rutting resistance of asphalt binder increase significantly. All of the results above verified that the effect of hygrothermal cycling could accelerate the aging of HVMA and shorten its service life.

High-Temperature Characteristics of Polyphosphoric Acid-Modified Asphalt and High-Temperature Performance Prediction Analysis of Its Mixtures

To promote the application of economical and sustainable polyphosphoric acid (PPA)-modified asphalt in road engineering, styrene-butadiene block copolymer (SBS), styrene-butadiene rubber (SBR), and PPA were used to prepare PPA/SBS and PPA/SBR composite-modified asphalts, which were tested and the data analyzed. Fourier transform infrared spectroscopy (FTIR) tests and thermogravimetric analysis (TG) tests were carried out to study the modification mechanisms of the composite-modified asphalts, and the high-temperature performance of the PPA-modified asphalt and asphalt mixtures was analyzed by dynamic shear rheology (DSR) tests and wheel tracking tests. A gray correlation analysis and a back-propagation (BP) neural network were utilized to construct a prediction model of the high-temperature performance of the asphalt and asphalt mixtures. The test results indicate that PPA chemically interacts with the base asphalt and physically integrates with SBS and SBR. The PPA-modified asphalt has a higher decomposition temperature than the base asphalt, indicating superior thermal stability. As the PPA dosage increases, the G*/sinδ value of the PPA-modified asphalt also increases. In particular, when 0.6% PPA is combined with 2% SBS/SBR, it surpasses the high-temperature performance achieved with 4% SBS/SBR, suggesting that PPA may be a good alternative for polymer modifiers. In addition, the creep recovery of PPA-modified asphalt is influenced by the stress level, and as the stress increases, the R-value decreases, resulting in reduced elastic deformation. Furthermore, the BP neural network model achieved a fit of 0.991 in predicting dynamic stability, with a mean percentage of relative error (MAPE) of 6.15% between measured and predicted values. This underscores the feasibility of using BP neural networks in predictive dynamic stability models.

Plant Waste-Based Bioadditive as an Antioxidant Agent and Rheological Modifier of Bitumen.

In recent times, circular economy initiatives in addition to the need for sustainable biomaterials have brought about several attempts at the eco-friendly, eco-sustainable and cost-effective production of asphalt pavements. It is an increasingly common practice in the asphalt industry to improve road pavement performance using additives to enhance the physico-chemical properties of bitumen, which performs the role of the binder in the asphalt mix. This paper evaluated the potential of a bio-based additive derived from olive leaf residue as a modifier and antioxidant agent for bitumen. Samples of neat, aged and doped aged bitumen were analyzed. In this study, the two bio-based additives were characterized in terms of phenol, chlorophyll, lignin and cellulose content, which was correlated with the mechanical properties of the tested samples. The mechanical properties of the neat, modified, aged and unaged samples were evaluated via Dynamic Shear Rheology. The bio-based additives proved to be promising and can improve the properties of bitumen binder and the performance of asphalt pavements in general.

Plant-based delivery systems for controlled release of hydrophilic and hydrophobic active ingredients: Pea protein-alginate bigel beads

Oral delivery systems for nutrients and nutraceuticals are required for personalized nutrition applications. In some applications, these delivery systems need to encapsulate both hydrophilic and hydrophobic bioactive agents. In this study, bigel beads (2 mm) were prepared using pea protein (PP) and sodium alginate (SA) to form the hydrogel phase, and glyceryl monostearate and soybean oil to form the oleogel phase. The hydrogel phase was crosslinked by using Ca2+ ions to form electrostatic bridges between the alginate molecules. The bigel beads had an oil-in-water type structure consisting of an oleogel dispersed phase within a hydrogel continuous phase. These beads were used to encapsulate and control the release of model hydrophobic (curcumin) and hydrophilic (epigallocatechin gallate) nutraceuticals. The textural and microstructural characteristics of the bigel beads were evaluated by dynamic shear rheology, textural profile analysis, cryo-electron microscopy, and fluorescence confocal microscopy. As the concentration of SA increasing from 0.2 to 1.0%, the hardness of bigel beads increased from 306.75 g to 792.40 g. In vitro digestion experiments showed that most of the nutraceuticals were released in the small intestine, rather than the stomach. Nutraceutical release could be controlled by manipulating bead composition, with the extent of nutraceutical release decreasing with increasing alginate concentration. The bigel beads developed in this study could be used as easy-to-swallow carriers for the controlled release of hydrophilic and hydrophobic bioactive ingredients. These kinds of products may be especially useful for people with dysphagia.

Waste cooking oil as a sustainable solution for UV-aged asphalt binder: Rheological, chemical and molecular structure

Recycling of UV-aged asphalt has been a hot research issue. In this paper, waste cooking oil, plasticizer, toughener, and petroleum resin were used as raw materials for asphalt rejuvenator. This paper explores the effect of regeneration conditions on the regeneration effect of UV-aged asphalt binders through high-temperature rheology and chemical compositions. The paper also attempts to reveal the regeneration mechanism of asphalt binder regeneration using waste cooking oil. Dynamic shear rheology (DSR) and fourier transform infrared (FTIR) spectroscopy assess high-temperature rheological properties and chemical compositions. The Pearson correlation coefficient relates the rheological parameters to the chemical microstructure. And the functional relationship between carbonyl-corrected peak area and aging factor Ai of recycled asphalt and high temperature rheological parameters were established. Molecular simulation investigates WCO-recycled asphalt binder micro-morphology and adsorption mechanisms. The results showed that significant changes in the carbonyl and sulfoxide peak areas affected the high-temperature rheological properties. Regeneration conditions significantly affect asphalt regeneration effectiveness. WCO reduces CO and SO groups, crucial in asphalt viscoelastic behavior. Molecular interaction analysis reveals WCO's regenerative mechanism. This work emphasizes integrating molecular structure, chemical composition, and macroscopic properties in asphalt binder research, providing insights for sustainable pavement practices.

Study on Viscoelastic Properties of Various Fiber-Reinforced Asphalt Binders.

This study analyzed the viscoelastic properties of asphalt binders reinforced with various fibers, such as modified asphalt binder, modified asphalt binder reinforced with lignin fibers (LFs), polyester fibers (PFs), and polypropylene fibers (PPFs), using dynamic shear rheological (DSR) testing. Then, the experiment generated data on the dynamic modulus and phase angle, which described the dynamic rheological characteristics at varying temperatures. The generalized Maxwell model was employed to select the appropriate element, and the test curve was fitted into a discrete time spectrum based on the time-temperature equivalence principle (TTSP). The master curves of the relaxation modulus and creep compliance were established to predict the relaxation and creep properties of various asphalt binders. The analysis indicated that fiber-reinforced binders offer superior resistance to high temperatures and long-term deformation, while being less sensitive to temperature and having a more significant elastic characterization. The binders reinforced with PPFs and LFs exhibited superior performance in high-temperature settings and long-term durability, respectively. On the other hand, the binder reinforced with PFs displayed exceptional high-temperature elastic properties. Additionally, based on the experimental data and corresponding discussion, it appears that the 13-element GM model is more appropriate for fitting the data.