Network Microstructure Research Articles

Controlling of microstructures and mechanical properties based on the non-equilibrium microstructures of a nickel-based superalloy fabricated by laser powder bed fusion

In this paper, we propose a novel idea of controlling microstructure and mechanical properties based on the non-equilibrium microstructure of nickel-based superalloy fabricated by laser powder bed fusion (LPBF). The network microstructures were firstly built in LPBF nickel-based superalloys by direct aging (DA) heat treatment. Thermodynamic calculations were conducted to design the DA and homogenizing + DA (HDA) heat treatments for elucidating the control mechanism. The results showed that the non-equilibrium microstructures in as-built nickel-based superalloy contributed to the network microstructure formation and recrystallization during DA heat treatment. The grains were refined and the <001> texture was eliminated after DA heat treatment. The non-equilibrium microstructures were removed and the recrystallized grains tended to coarsen after HDA heat treatment due to high temperature homogenizing treatment. The in-situ nano γ′ phase uniformly distributed in the grains of HAD-treated microstructures, which was also found inside network microstructures of DA-treated microstructures. Due to the additional strengthening effect of refined grains and network microstructures, the strength of DA-treated sample was higher than those of as-built and HAD-treated samples, while the ductility was lower than that of as-built sample, and but was close to that of HAD-treated sample. This study will provide guidance for developing a suitable heat treatment process of LPBF nickel-based superalloys.

A WOA-BP neural network microstructure evolution prediction model of TC11 titanium alloy and application in hollow shaft during cross wedge rolling with mandrel

A WOA-BP neural network microstructure evolution prediction model of TC11 titanium alloy and application in hollow shaft during cross wedge rolling with mandrel

Experimental study on EDM of network microstructure titanium matrix composites

ABSTRACT The network microstructure titanium matrix composites (NMTMCs) exhibit excellent properties but research on its machining remains limited. In this paper, single and continuous pulse electrical discharge machining (EDM) experiments were conducted on the NMTMCs composed of Ti6Al4V matrix combined with 5% vol. network distributed TiB whisker (TiBw). The impact of TiBw on EDM was analyzed in comparison to the machining results of pure Ti6Al4V. The results indicate that the TiBw reinforcements absorbs pulse energy during the machining process, resulting in smaller areas and more complex morphologies for the EDM craters. Based on this, a linear absorption model for pulse energy by reinforcement strips is proposed. Furthermore, in continuous pulse EDM with low capacitance settings, the presence of TiBw tends to generate micro pores on the surface and reduce material removal rate (MRR). However, when using higher capacitance settings, MRR for NMTMCs can surpass that achieved for pure Ti6Al4V.

Structural, physicochemical, prebiotic properties of guava pulp insoluble dietary fiber and its quality enhancement ability on cow/goat yogurt: Impacts of ultrasound-assisted enzyme treatment

This study explores the effect of ultrasound-assisted cellulase (UE) processing on the structure, functional performance, and prebiotic properties of guava insoluble dietary fiber (RIDF). As the ultrasound exposure time increased (0–40 min), the particle size (from 126.3 μm to 38.7 μm) and crystallinity (from 30.72% to 14.42%) of RIDF significantly decreased, while its soluble carbohydrate content (from 1.40% to 6.17%) and water solubility (from 8.6% to 16.4%) notably increased. These crucial changes suggested the degradation and disorganization of RIDF. Meanwhile, UE-RIDF (modified RIDF) demonstrated a honeycomb network microstructure with a larger surface area, indicating distinct structural and morphological properties compared to RIDF. Consequently, UE-RIDF showed stronger retention/adsorption capacity and improved in vitro prebiotic activity. Interestingly, UE treatment increased RIDF fermentability, leading to additional shifts in its modulation of human fecal microbiota, including a higher abundance of Proteobacteria and Phascolarctobacterium. Furthermore, compared to pure cow/goat yogurt, yogurt fermented with UE-RIDF displayed a lower pH, better stability, and improved texture and rheological properties during a 21-day refrigeration period. These findings highlight the potential application of RIDF as a novel prebiotic active ingredient in fermented foods for the first time, underscoring the critical role of UE treatment in enhancing its performance.

Effect of soluble dietary fiber on soy protein isolate emulsion gel properties, stability and delivery of vitamin D3

Emulsion gels with denser network microstructure and stronger mechanical properties have attracted increasing attentions for delivering lipophilic compounds. In this study, the effect of three distinct soluble dietary fiber (inulin (IN), resistant dextrin (RD) and stachyose (ST)) on the rheological, mechanical and microstructural properties of soy protein isolate (SPI) emulsion gel were firstly investigated. Compared with RD and IN, ST significantly accelerated water holding capacity and thermal stability, which exhibited more compact microstructure and more uniform emulsified oil droplets. Subsequently, the stability and bioavailability of vitamin D3 (VD3) in different delivery systems (medium chain triglycerides (MCT) embedding, SPI-ST emulsion embedding, SPI emulsion gel embedding and SPI-ST emulsion gel embedding) were continue evaluated. In vitro simulated digestion experiment demonstrated that the bioaccessibility of encapsulated VD3 in SPI-ST emulsion gel (69.95 %) was much higher than that of free embedding (48.99 %). In vivo pharmacokinetic experiment revealed that the bioavailability of VD3 was significantly enhanced in SPI-ST gel (p < 0.05), with the AUC0-24h value of 25-OH VD3 (the main circulating form of VD3) were 1.34-fold, 1.23-fold higher than that of free embedding, MCT embedding, respectively. These findings provide a possible approach for the development of high protein/fiber functional foods containing enhanced hydrophobic bioactives.

Fermentation Characteristics, Antinutritional Factor Level and Flavor Compounds of Soybean Whey Yogurt.

Soybean whey contains high levels of off-flavors and anti-nutritional factors and is generally considered unsuitable for direct application in the food industry. In this work, to reduce beany off-flavors and anti-nutritional factors, and to improve its fermentation characteristics, soybean whey was treated with electrodialysis desalination, vacuum concentration and lactic acid bacteria (LAB) fermentation. The results showed that electrodialysis desalination increased the fermentation rate and the number of viable lactic acid bacteria of soybean whey yogurt. More than 90% of the antinutritional factor level (urease and trypsin inhibitory activity) was removed due to high-temperature denaturation inactivation and LAB degradation. Concentrated desalted soybean whey yogurt (CDSWY) possessed larger values for firmness and consistency, and a denser network microstructure compared with undesalted yogurt. Over 90% of off-flavors including hexanal, 1-octen-3-ol and 1-octen-3-one were removed after electrodialysis desalination and concentration treatment. Meanwhile, the newly generated β-damascenone through carotenoid degradation and 2,3-butanedione improved the pleasant flavor and sensory quality of CDSWY, while the salty taste of CSWY lowered its sensory quality. This study provided a theoretical basis for better utilization of soybean whey to develop a plant-based yogurt like dairy yogurt.

The effect of agar on rheological properties and thermal stability of rennet-induced casein micelle gel

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.

The effects of B4C network microstructure on the thermoelectrical properties of spark plasma sintered SiC

The effects of B4C network microstructure on the thermoelectrical properties of spark plasma sintered SiC

The effects of TiC network microstructure on the mechanical properties of spark plasma sintered Al2O3

The effects of TiC network microstructure on the mechanical properties of spark plasma sintered Al2O3

Development of Hydrophilic Oxide/Polymer Composite Membranes for Polymer Electrolyte Fuel Cells Operating at Wide Temperature Range

Toward the wide-spread use of heavy-duty vehicles (HDVs) operated by polymer electrolyte fuel cells (PEFCs) should approach the higher temperature around 120oC besides normal temperature (60-80oC). Commercial perfluorosulfonic acid-based electrolyte (PFSA, e.g. NafionⓇ) shows better proton conductivity with chemical stability in wide temperatures range, though decreases under low back pressure at 100~120 oC. In order to improve the proton conductivity at the higher temperature range, composite membrane of NafionⓇ with a hydrophilic filler of Ta doped TiO2 (Ta-TiO2) was synthesized. The Ta-TiO2 nanoparticles fillers with fused-aggregate network microstructure were synthesized by the flame method, and were crushed by wet mill(Star Burst, :Sugino Machine Limited CO.). The fillers were mixed with NafionⓇsolution (20 wt.%：D2020 Chemours Co.) by use of a rotary ultrasonic dispersing processor (500 rpm, 60 min. PR-1 :Thnky Co.), a planetary ball mill (500 rpm、30 min.：PULVERISETTE 6：FRITSCH Co.), and a defoaming processor (500 rpm、5 min.：HM-400W: Kyouritu Seiki). The dispersion solution was coated in hot air by use of a die coating system (die coater: Taku-Dai Mini-50: Daimon Co., Ltd.), and were hot-pressed (140 ℃ 3 min. TCMD-2.5:TOHO KOGYO co.) to form composite membranes (9 cm×9 cm ×25 µmt).The cross-sectional backscattered electron image BSE) of the composite membrane observed by scanning electron microscope (SEM, acceleration voltage 2 kV, SU9000: Hitachi High-Tech Co.) and transmission electron microscope (TEM, H-9500: Hitachi High-Tech Co.). The proton conductivity of the composite membrane was measured by the AC four-probe method. The current-voltage (IV) polarization curves of Single cells using the prepared composite membrane (membrane thickness: 25 µm) were measured at 80 ℃ 100% RH and 120 ℃ 20% RH, back pressure 50 kPaG.The obtained composite membranes were well flexibility with softness. The BSE images indicated that the high contrast images of Ta-TiO2 parties were uniformly dispersed in composite membrane. The higher magnified of the cross-sectional TEM images also showed that the hydrophilic surface of Ta-TiO2 adhered to the Nafion® without any air pores. The proton conductivity of the composite membrane at 80% RH increased with increasing Ta-TiO2 content and showed maximum value of 0.13 S cm-1at 3 wt%, and then decreased. The maximum proton conductivity was 1.3 times higher than that of Nafion®. The IV performance of the single cell using composite membrane kept same performance to that using Nafion® membrane at 80 oC 100% RH, and then improved at 120 oC 20% RH. The water content at 120 oC 20% RH kept higher value by the effect of hydrophilicity of the Ta-TiO2, which would be one of the reasons to enhance the cell performance at 120 oC 20% RH. Figure 1

Set yoghurt processing with eggs as milk replacements, and improvement of texture, rheology, and microstructure by formulation design and optimisation

Eggs are suitable for the processing of set yoghurt as milk replacements, but there is no yoghurt mainly made from eggs. In the present work, production formula was designed and optimised for high-quality egg-based yoghurt processing by improving water holding capacity, aroma, texture, and taste using single factor experiment and D-optimal mixture design. Results showed that with optimised formula (whole liquid egg, 100 g; water, 180 g; sucrose, 30.89 g; diacetyl tartaric acid ester of mono(di)glycerides, 0.28 g; gelatine, 0.112 g; gellan gum, 0.14 g; and β-cyclodextrin, 0.56 g), the product showed high sensory evaluation score, fine viscosity, as well as preferable hardness and suitable fracturability. SDS-PAGE electrophoretogram indicated that the proteins in egg-based yoghurt was degraded during fermentation, which might have contributed to the improvement of gel structure and taste. Based on the SEM images, the prepared egg-based yoghurt had smoother, stronger, and more compact gel network microstructure when compared with milk-based yoghurt.

Interrelation between ink viscoelasticity and crack structure of fuel cell microporous layers

Cracks in the microporous layers of fuel cells greatly affect their performance. It is essential to understand the viscoelasticity of ink, the key precursor during MPL fabrication, to gain insights into crack formation and control. This work has comprehensively investigated ink rheology with different solid content and the resulting MPL crack structure from a theoretical and practical level. The network microstructure strength of the ink is evaluated by rheological measurements, and the interrelation between ink viscoelasticity and two distinct crack configurations is established. The detailed SEM characterization shows that an appropriate ink cohesive energy produces more intersected cracks within the MPL, while lower or higher cohesive energy is prone to unpenetrated and interlayer cracks. The range of CE in this study is 0.03–100 J/m3, the CE of ink is more likely to produce intersected cracks at about 10 J/m3. Moreover, the CE variation affects the PTFE distribution. A lower CE variation from 1 to 500 s−1 which is associated with the coating process promotes a homogeneous PTFE distribution.

Mechanical properties and micro-mechanism of improved shield tunnel muck with phosphogypsum and lime

Massive shield tunnel muck is being landfilled without effective use due to high moisture contents and poor engineering properties, which not only leads to soil resources waste, but also occupies a large amounts of land sources. In this study, industrial waste phosphogypsum (PG) was recycled to improve the tunnel muck with lime, and the improved muck is aiming to be used in subgrade filling. A series of laboratory tests, including compaction tests, unconfined compressive strength (UCS) tests, california bearing ratio (CBR) tests, resilient modulus tests and microscopic tests were carried out. The effects of PG, lime, carboxymethyl cellulose (CMC) and moisture contents on physical, mechanical and microscopic properties of improved muck were examined, respectively. Results indicate that the incorporation of lime and PG significantly improves the mechanical properties and water stability of shield tunnel muck generated in silt stratum. The performance of improved tunnel muck meets the requirement for subgrade filling. Notably, for a fixed total contents of lime and PG, the proportion of 3:1 lime/PG results in the best mechanical properties and water stability. The tunnel muck generated in silt stratum mainly consists of lamellar and layered structures, which contributes to stronger cohesion among soil particles and the hydration products. The CMC has the ability to create cementation bonds among soil particles and the hydration products of lime and PG, resulting in a denser gel network microstructure.

Liquid Crystalline Network Microstructures for Stimuli Responsive Labels with Multi-Level Encryption.

Two-photon direct laser writing enables the fabrication of shape-changing microstructures that can be exploited in stimuli responsive micro-robotics and photonics. The use of Liquid Crystalline Networks (LCN) allows to realize 3D micrometric objects that can contract along a specific direction in response to stimuli, such as temperature or light. In this paper, the fabrication of free-standing LCN microstructures is demonstrated as graphical units of a smart tag for simple physical and optical encryption. Using an array of identical pixels, information can be hidden to the observer and revealed only upon application of a specific stimulus. The reading mechanism is based on the shape-change of each pixel under stimuli and their color that combinetogether in a two-level encryption label. Once the stimulus is removed, the pixels recover their original shape and the message remains completely hidden. Therefore, an opto-mechanical equivalent of an "invisible ink" is realized. This new concept paves the way for introducing enhanced functionalities in smart micro-systems within a single lithography step, spanning from storage devices with physical encryption to complex motion actuators.

Ultrasound‐assisted chlorogenic acid‐grafted chitosan soaking of sea bass (Lateolabrax japonicus) fillets to reduce protein oxidation and maintain gel properties

AbstractThe perishability of aquatic products is a challenge for the processing of aquatic products, so it is better to choose suitable preservatives to prevent the degradation of proteins and the fission of their gel properties. Thus, this study investigated the effects of ultrasound‐assisted chlorogenic acid grafted chitosan (GUA) soaking of sea bass (Lateolabrax japonicus) fillets on protein oxidation and gelation properties. The results showed that GUA could reduce the formation of protein carbonyls and maintain Ca2+‐ATPase activity. Intrinsic fluorescence intensity (IFI) and SDS‐PAGE results demonstrated that GUA stabilized the tertiary structure of protein and inhibited protein degradation. Interestingly, ultrasound attenuated the protein aggregation induced by the use of chitosan‐grafted‐chlorogenic acid (CS‐g‐CA), which has good particle size during storage. Meanwhile, GUA treatment endowed the gel with a dense network microstructure, increased water holding capacity (WHC), reduced water mobility, and improved MP gel color as well as textural properties.

Use of basic amino acids to improve gel properties of PSE-like chicken meat proteins isolated via ultrasound-assisted alkaline extraction.

To improve the gel quality of pale, soft, and exudative (PSE)-like chicken protein isolate (PPI) obtained via ultrasound-assisted alkaline extraction (UAE), l-lysine (l-Lys), l-arginine (l-Arg), or l-histidine (l-His) were used and the effects on the thermal gelling characteristics of PPI were studied. Compared with the nonbasic amino acid addition group, the addition of l-His/l-Arg/l-Lys significantly increased the solubility and absolute zeta potential of PPI, whereas reduced the particle size and turbidity (p<0.05). They enhanced the gel strength and textural properties of PPI (p<0.05) and reduced the cooking loss of PPI in the following order: l-Lys>l-Arg>l-His. The solubility, gel strength, and hardness of PPI with l-Lys were increased by 18.6%, 44.6%, and 57.6%, respectively, and cooking loss was decreased by 18.1%. Low-field nuclear magnetic resonance and magnetic resonance imaging revealed that basic amino acids addition decreased the water mobility in PPI gels with increasing immobile water content. Scanning electron microscopy revealed that the addition of basic amino acids promoted the formation of a more uniform and tight network microstructure in PPI gels. The α-helix content was decreased, whereas the β-sheet content was increased in PPI gels after basic amino acid addition. Therefore, addition of basic amino acids, especially l-Lys, enhances the gel properties of PPI. PRACTICAL APPLICATION: This study revealed that adding basic amino acids effectively improved the gel properties of PPI obtained via UAE method, with l-Lys exerting the best improvement effect. Our findings highlight the application value of PSE-like meat by the improvement of gel characteristics of PPI, providing a theoretical reference for the processing and utilization of PPI.

Quantitative image analysis of influence of polysaccharides on protein network formation in GDL-acidified milk gels

Exopolysaccharides (EPS) are commonly used to improve the texture of yogurt. These polysaccharides interact with casein micelles, the major protein in milk, via electrostatic and depletion mechanisms during fermentation by lactic acid bacteria (LAB). However, the relationship between the physicochemical properties and monosaccharide composition of EPS and their impact on yogurt texture is not yet fully understood. To address this knowledge gap, we studied the effects of polysaccharides commonly used as food additives on acid-induced milk protein networks. Confocal laser scanning microscopy (CLSM) was used to image the network microstructures. Image analysis, including Fourier transform, autocorrelation, and binarization-based techniques, was applied to quantify key structural features of the mixed milk protein/polysaccharide gels. These parameters were then related to the macroscopic properties of the model food matrices, such as elastic and viscous moduli and yield point. We found that the addition of neutral polysaccharides resulted in a concentration-dependent increase in structure factor, protein domain size, and pore fraction. In contrast, the presence of charged polysaccharides led to an increase in protein domain size, a decrease in pore fraction, and a decrease in elastic and viscous moduli. These results demonstrate the use of a quantitative image analysis method for selecting LAB with favorable EPS properties to improve yogurt texture.

Versatile fiber-reinforced hydrogels to mimic the microstructure and mechanics of human vocal-fold upper layers

Human vocal folds are remarkable soft laryngeal structures that enable phonation due to their unique vibro-mechanical performances. These properties are tied to their specific fibrous architecture, especially in the upper layers, which comprise a gel-like composite called lamina propria. The lamina propria can withstand large and reversible deformations under various multiaxial loadings. Despite their importance, the relationships between the microstructure of vocal folds and their resulting macroscopic properties remain poorly understood. There is a need for versatile models that encompass their structural complexity while mimicking their mechanical features. In this study, we present a candidate model inspired by histological measurements of the upper layers of human vocal folds. Bi-photonic observations were used to quantify the distribution, orientation, width, and volume fraction of collagen and elastin fibers between histological layers. Using established biomaterials, polymer fiber-reinforced hydrogels were developed to replicate the fibrillar network and ground substance of native vocal fold tissue. To achieve this, jet-sprayed poly(ε-caprolactone) fibrillar mats were successfully impregnated with poly(L-lysine) dendrimers/polyethylene glycol hydrogels. The resulting composites exhibited versatile structural, physical and mechanical properties that could be customized through variations in the chemical formulation of their hydrogel matrix, the microstructural architecture of their fibrous networks (i.e., fiber diameter, orientation and volume fraction) and their assembly process. By mimicking the collagen network of the lamina propria with polymer fibers and the elastin/ground substance with the hydrogel composition, we successfully replicated the non-linear, anisotropic, and viscoelastic mechanical behavior of the vocal-fold upper layers, accounting for inter/intra-individual variations. The development of this mimetic model offers promising avenues for a better understanding of the complex mechanisms involved in voice production. Statement of significanceHuman vocal folds are outstanding vibrating soft living tissues allowing phonation. Simple physical models that take into account the histological structure of the vocal fold and recapitulate its mechanical features are scarce. As a result, the relations between tissue components, organisation and vibro-mechanical performances still remain an open question. We describe here the development and the characterization of fiber-reinforced hydrogels inspired from the vocal-fold microstructure. These systems are able to reproduce the mechanics of vocal-fold tissues upon realistic cyclic and large strains under various multi-axial loadings, thus providing a mimetic model to further understand the impact of the fibrous network microstructure in phonation.

Anodic/Cathodic Properties of Ni Based Catalysts for Anion Electrolyte Membrane Water Electrolysis

Anion electrolyte membrane water electrolysis (AEM WE) using non-precious metal catalyst is one of the most prospective systems for pure hydrogen generation. The Ni based oxide shows relatively lower overpotential of oxygen evolution reaction (OER) by adding the transition metals of Co, Fe and Mn, and approaches that of precious metal of Ir based oxide. Our previous study reported that the Ni-Co based catalyst was highest OER activity at operating temperature. The crystallized Ni-Co metal-based core particles with amorphous Ni oxyhydrates of top surface (shell) was confirmed to be preferable to obtain the higher OER activity by rotating disk electrode method, transmission electron microscopy and DFT calculation. Moreover, the fused aggregated network microstructure of Ni-Co based catalyst assisted to show a metallically electronic conductivity. In this study, we evaluated both OER and hydrogen evolution reaction (HER) activity of Ni based catalysts to confirm the prospective non-precious metal catalysts for AEM WE.Each Ni based catalysts with additive of transition metals were synthesized by the flame oxide-synthesis method.1 The OER and HER activities of these catalysts were evaluated in 1 M KOH at 20 to 80 oC by use of the RDE. The Ni-Co based catalyst was highest OER activity in these Ni based catalysts obtained above. The amorphous top surface layer was correlated with a negative shift in the oxyhydroxide formation peak potential from the results of DFT calculations. 2 The HER activity of the Ni-Fe based catalyst also showed the higher OER activity. Especially, the Ni-Fe based catalyst had highest HER activity in these Ni cased catalysts above. The HER activity enhanced by the construction of well crystallized top surface in comparison with its amorphous or poorly crystalline ones. DFT calculation indicated that the defective or disordered surface was not as active for the HER. These results will provide a strategy of Ni based catalysts optimization for AEM. Acknowledgement This work was partially supported by funds for the JSPS KAKENHI (20H02839), and the project from the New Energy and Industrial Technology Development Organization (NEDO) of Japan. References Kakinuma, M. Uchida, T. Kamino, H. Uchida, and M. Watanabe, Electrochim. Acta, 56, 2881 (2011).Shi, T. Tano, D. A. Tryk, A. Iiyama, M. Uchida, and K. Kakinuma, ACS Catal., 11, 5222 (2021). Figure 1

Effect of arabinoxylan amount and molecular structure on the microstructure, physicochemical and delivery properties of casein/arabinoxylan composite hydrogels

In this study, arabinoxylans (AXs) with different molecular structures were first extracted from corn brans using different concentrations of NaOH (0.25, 0.5, 0.75 and 1 M). AX extracted with 0.25 M NaOH (AX-0.25 M) had the highest ferulic acid content of 5.11 mg/g and AX extracted with 1 M NaOH (AX-1 M) had the lowest arabinose to xylose ratio of 0.47. Meanwhile, the molecular structure of AX and its addition amount both had an influence on the microstructure and physicochemical properties of dual-induced casein/arabinoxylan composite hydrogels (CAS/AX hydrogels) by laccase and glucono-δ-lactone. With CAS/AX mass ratio of 16:1, CAS/AX-0.25 M and CAS/AX-1 M hydrogels exhibited stronger gel strength, better water holding capacity, higher hardness, gumminess and epigallocatechin gallate (EGCG) loading capacity, which was possibly due to their stronger covalent and non-covalent interactions, and denser network microstructures. Besides, the EGCG-loaded CAS/AX-0.25 M hydrogel with CAS/AX mass ratio of 16:1 showed the lowest EGCG cumulative release percentage in 2 h of simulated gastric fluid (31.56%) and 4 h of simulated intestinal fluid (52.94%), while almost all the remaining EGCG (46.57%) was fast released in simulated colonic fluid, showing the most optimum colon-targeted release behavior and protection of EGCG at low pH and protease degradation conditions.