Hydrolytic Behavior Research Articles

Computational Explorations of Th4+ First Hydrolysis Reaction Constants: Insights from Ab Initio Molecular Dynamics and Density Functional Theory Calculations.

The fundamental hydrolysis behavior of tetravalent actinide cations (An4+) with a high charge is crucial for understanding their solution chemistry, particularly in nuclear fuel reprocessing and environmental behavior. Using Th4+ as a reference of the An4+ series, this work employed both the periodic model and the cluster model to calculate the first hydrolysis reaction constant (pKa1) of the Th4+ aqua ion and conducted a detailed evaluation of these approaches. In the periodic model, ab initio molecular dynamics (AIMD) simulations of Th4+ in the explicit solvation environment are conducted, using metadynamics and constrained molecular dynamics to calculate pKa1 values. Metadynamics simulations with sufficient sampling yielded a value of 5.02, aligning with the experimental values (4.12-4.97). Moreover, AIMD results reveal further Grotthuss-type proton transfers and changes in the solvent structures, which are important for accurately modeling the hydrolysis process. In the cluster model, density functional theory calculations are performed on isolated hydrate clusters to obtain pKa1 values, describing solvation effects through the cluster-continuum model. Based on insights from the periodic models, particularly regarding further proton transfer, the cluster model was modified and tested using different functionals and similar cations (La3+and Ac3+). The pKa1 values obtained in the cluster model also show good agreement with the experimental values. The current computational approaches provide a comprehensive understanding of Th4+ hydrolysis and a reference framework for studying the hydrolysis of other lanthanide and actinide ions.

Selective colorimetric detection of carbosulfan based on its hydrolysis behavior and Ti3C2/AuPt nanozyme

BackgroundCarbosulfan (CBS) is a widely used carbamate pesticide in agricultural production, its easy decomposition into hypertoxic carbofuran poses serious threats to human health and food safety. Therefore, sensitive and accurate detection of CBS is of significant importance. Conventional chromatography-based techniques require expensive instruments and complicated sample pretreatment, limiting their application for fast detection. Current electrochemical and colorimetric methods for detection of pesticides based on the cascade catalytic reactions between acetylcholinesterase (AChE) and nanozymes, which exhibit inferior selectivity. Hence, selective, sensitive and fast detection of CBS is still challenging. ResultsIn this work, an AChE-free colorimetric method was proposed for selective detection of CBS based on its unique hydrolysis behavior and nanozyme. Ti3C2 nanosheets/AuPt nanoparticles (Ti3C2/AuPt NPs) with enhanced peroxidase-like activity were prepared via one-step self-reduction reaction. CBS can be hydrolyzed under acidic condition and produce -SH moieties, which could bond to Pt atoms of Ti3C2/AuPt NPs and shield the active sites of nanozyme, resulting in decreased catalytic activity. Based on the inhibitory effect on the peroxidase-like activity of Ti3C2/AuPt NPs, a colorimetric method was proposed for direct detection of CBS. Under optimal conditions, the method showed wide linear range (0.5 ng mL−1-5 μg mL−1), low limit of detection (0.342 nM), good selectivity and anti-interference ability. The feasibility of this method for practical use was confirmed by analysis of CBS in real lake water samples. SignificanceThis work proposed a simple colorimetric method for selective and fast detection of CBS, which avoided employing AChE and cascade catalytic reactions, significantly lowering the detection cost and improving detection efficiency. The method showed great potential for accurate detection of CBS in actual samples, and provided a new avenue for developing nanozyme-based colorimetric method for detection of other pesticide residues.

Hydrolysis behavior evaluation of sports protein supplements with different composition and dosage forms: In vitro dynamic gastric digestion

Hydrolysis behavior evaluation of sports protein supplements with different composition and dosage forms: In vitro dynamic gastric digestion

Elucidating trends in synthesis and structural periodicity in a series of tetravalent actinide–oxo hexamers

Differences in synthetic conditions and structural systematics in a series of actinide–oxo clusters reflect trends in the hydrolysis behavior of the tetravalent metal ions, Th–Pu.

Effect of Food-Simulating Liquids on Hydrolytic Behavior of Resin Matrix Ceramics.

This study aimed to evaluate the hydrolytic behavior of different computer-aided design/computer-aided manufacturing (CAD/CAM) resin matrix ceramics (RMCs) in different food-simulating liquids (FSLs). Five different CAD/CAM blocks, one from polymer-infiltrated ceramic networks (PICNs; Vita Enamic (EN)) and four from resin-based composites (RBCs; Lava Ultimate (UL), Cerasmart (CER), Brilliant Crios (BR), and Block HC (HC)) were selected. Forty specimens were prepared for each material, and they randomly distributed to each FSLs. The specimens were kept in a desiccator initially, then placed in 5 ml of liquid at 37±1°C for 30 days and weighed at various time intervals. Percentage mass change (Mg%), sorption (SP), percentage of liquid absorbed (SP%), solubility (SL), percentage solubility (SL%), and percentage of liquid absorbed by the polymer matrix (SPpm) water absorption of the specimens were evaluated. Significance was evaluated at p<0.05 levels. Hydrolytic behavior of the materials showed statistical differences in terms of SP, SL, SP%, and SL% values depending on the liquid environment (p=0.001). The highest SP values were obtained from the HC material in saliva, and the lowest values were obtained from the BR in ethanol. The highest SL values were obtained from the CER and EN in heptane, and the lowest values were obtained from the HC in ethanol. However, all results detected in the study remained below the ISO threshold values. All materials tested exhibited clinically acceptable hydrolytic behavior over the time tested. Not only the material content but also many factors can affect the hydrolytic behavior.

Two mixed-valent cerium oxo clusters: synthesis, structure, and self-assembly.

Studies on cerium oxo clusters (CeOCs) are not only significant for understanding the redox and hydrolysis behaviors of Ce(III/IV) ions but also crucial for the rational synthesis of novel clusters and nanoceria with specific Ce(III)/Ce(IV) ratios. Here, two sets of reactions were conducted using cerium nitrate and H2O2-oxidized cerium nitrate, resulting in the formation of two distinct mixed-valent CeOCs [CeIII 4CeIV 10O14(OH)2(PhCO2)22(DMF)6] (Ce14) and [CeIII 2CeIV 22O28(OH)8(PhCO2)30(DMF)4] (Ce24C). These two clusters exhibit different structures and Ce(III)/Ce(IV) ratios, demonstrating the critical role of cerium oxidation states and the occurrence of redox reactions in cluster formation. Ce14 is the first tetradecanuclear CeOC with a novel structure, whereas Ce24C differed in its Ce(III)/Ce(IV) ratio, protonation levels of O atoms, and ligands from previously reported 24-nuclear CeOCs. Furthermore, various techniques were employed to investigate the formation process of these two clusters. X-ray photoelectron spectra (XPS) revealed that the white precipitates formed during the preparation of Ce14 contain Ce(III) ions, while the reddish-brown precipitates formed during the preparation of Ce24C contain a mixture of Ce(III) and Ce(IV) ions. These two precipitations were individually dissolved in N,N-Dimethylformamide (DMF). The evolution of solution color and ultraviolet-visible (UV-Vis) spectra over time revealed the gradual oxidation of partial Ce(III) ions by oxygen in the solution of the white precipitation. As Ce(IV) ions increased in this solution, time-resolved small angle X-ray scattering (SAXS) data demonstrated the self-assembly of the Ce14 clusters after 4days. In contrast, SAXS data and UV-Vis spectra revealed the rapid assembly of Ce24C clusters within 2h due to the initial coexistence of Ce(IV) and Ce(III) ions in the DMF solution of the reddish-brown precipitation. The continued reduction of partial Ce(IV) ions in this solution does not affect Ce24C clusters' formation and stability. Our studies expand the family of CeOCs and enhance our understanding of the effects of cerium's oxidation states on cluster formation.

Real-time tracking of the adsorption and degradation behavior of bovine serum albumin, casein, and fibrinogen on the lipid layer by optical interferometry.

Different kinds of proteins interact with the digestible lipids in various ways, affecting the adsorption behavior of proteins and digestion. The ordered porous layer interferometry (OPLI) system was constructed by the silica colloidal crystal (SCC) films used to monitor the real-time binding assessment between bovine serum albumin (BSA), casein, fibrinogen, and triolein. The OPLI system reflected the changes in protein mass on the SCC films in real time through the migration of the interference spectrum of the SCC films, which was converted into the changes in optical thickness (ΔOT) that can be monitored. OPLI systematically studied the degradation of proteins by trypsin and found that the lipid layer enhanced the hydrolysis of trypsin to BSA and fibrinogen but weakened the degradation of trypsin to casein. The high OT of the lipid layer (10.45 nm) indicated that trypsin was more likely to adhere to the casein surface on the lipid layer than to hydrolyze casein. In contrast, the reduced OT (-6.40 nm) on the SCC films indicated that trypsin was more inclined to hydrolyze casein than to attach to casein. The OPLI system provided the technical basis for real-time tracking of protein hydrolysis behavior in complex food systems.

The role of extraction method to collagen substrates in enzymolysis of type I collagenase

Collagens are ubiquitous biomaterials in animal tissues whose characteristic triple-helical structure can only be hydrolyzed under physiological conditions by a few specific proteases. At present, information on the differences of collagenase hydrolysis behavior to collagen substrate caused by extraction methods is still lacking. Acid-relaxed extracted collagen (ARC) and acetic acid-pepsin extracted collagen (APC) were obtained from bovine hide by acetic acid and acetic acid-pepsin extraction method, respectively. The enzymolysis behavior of type I collagenase on ARC and APC were investigated by means of fluorescence spectra, UV spectra, and determination the release of hydrolysates into the supernatant. The results revealed that APC showed a lower molecular weight, a higher pI (5.59) and denaturation temperature (Td = 66.9 °C) than that of ARC (pI = 4.67, Td = 57.8 °C). Moreover, APC demonstrated greater resistance to type I collagenase than ARC. The cleavage on the non-helical terminal domains by pepsin might play the role in the better thermal stability, the higher pI, and the more collagenase resistance of APC than ARC. The findings of this work should provide new insights into collagenase hydrolysis behavior and facilitate targeted utilization of collagen extracted by various method.

Surface modified cellulose nanospheres with simultaneous nucleation and degradation-accelerating effects on poly(lactic acid)

As a novel type of nanocellulose material, cellulose nanospheres (CNSs) have gained significant attention and rapid development in recent years. In this work, the surface hydrophobic modification of CNSs was achieved by employing maleic anhydride as an esterifying agent. The effects of modified cellulose nanospheres (CNS-MA) on the crystallization and hydrolysis behaviors of polylactic acid (PLA)-based composites were systematically investigated. The results demonstrate that surface modification improves the dispersion of CNSs in the PLA matrix. Well-dispersed particles act as nucleation sites, which increases the crystallization rate and crystallinity of PLA and endows the composites with remarkable heat distortion resistance. The storage modulus of the PLA/CNS-MA composites exceeds 300 MPa, even at an elevated temperature of 90 °C. Furthermore, the hydrolytic degradation of PLA is dramatically accelerated with the addition of CNS-MA. Combining the morphology observations and theoretical calculations, it is speculated that the fast hydrolytic degradation is related to a transition in the main hydrolytic degradation mechanism from surface erosion to bulk erosion, because the presence of CNS-MA provides particular pathways for water molecules to diffuse into the interior of the composites. This research highlights the potential of CNSs as a multifunctional filler with both reinforcing and degradation-promoting effects, offering valuable insights for the study of other biomass nanomaterials.

Developing zirconium xerogel coagulants for deep removal of phosphorous

Deep removal of phosphorous (P) from water is a necessary measure to solve the eutrophication problem. Coagulation is both a basic treatment method for P removal and an important pretreatment process for membrane filtration. However, few coagulants can meet the both requirements. Based on the analysis on the hydrolysis behaviors of some earth-abundant metals and the solubility products of their phosphates, a series of zirconium xerogel coagulants (ZXC) was fabricated with a novel approach (the sol-gel method) and was evaluated for the removal of both organic and inorganic P in coagulation and coagulation-ultrafiltration. In terms of P removal and anti-fouling of membrane, the resultant ZXC outperformed polyzirconium chloride (PZC), polyaluminum chloride (PAC), polyferric sulfate (PFS), as well as titanium xerogel coagulant (TXC) in a wide range of pH and dose. The rapid hydrolysis of Zr4+ and the formation of Zr3(PO4)4 with a rather low solubility product are attributable to the great performance of ZXC in coagulation. This study highlights the potential of ZXC as an effective solution for enhancing the treatment of water and wastewater, particularly in achieving deep P removal and improving membrane fouling resistance, thereby contributing to more sustainable and efficient strategies for addressing eutrophication and pollutant removal.

Effect of carbodiimides on the compatibility and hydrolytic behavior of PLA/PBAT blends

Blends of polylactic acid (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) have great potential to replace conventional polyolefin and polyester materials. However, poor compatibility and fast degradation rate limit its development. In this paper, the effects of two monomer-type carbodiimides and one polymerized carbodiimide on the crystalline, thermal stability, hydrolysis properties, and mechanical properties of PLA/PBAT blends are investigated by Fourier transform infrared spectroscopy, scanning electron microscope, differential scanning calorimetry, thermogravimetric analysis, gel permeation chromatography, melt mass-flow rate, terminal carboxyl content, tensile properties, and rotational torque. It is found that all the three carbodiimide additives can improve the compatibility and enhance the mechanical, processing, and thermal stability properties of PLA/PBAT blends except for their reduced crystallization performance. Moreover, regarding the hydrolysis properties, the two monomeric carbodiimides exhibit little effect on the hydrolysis of PLA/PBAT blends, even accelerating the degradation rate under alkaline conditions. However, the antihydrolysis effect of polycarbodiimide is remarkable, which effectively improves the compatibility and antihydrolysis properties of PLA/PBAT blends.

Arc-shaped air layer bioinspired by ginkgo nut to resist high humidity environment for PET fabrics

Developing simple processes and significant effect modification method for polyester (PET) fabrics to resist hygrothermal aging is a formidable challenge. In this study, inspired by the silver mirror phenomenon of natural ginkgo nut, we utilized the pea pod-shaped nanoparticles that zinc oxide (ZnO) was encapsulated in polyhedral oligomeric silsesquioxane (ZnO@POSS), and polydimethylsiloxane (PDMS) to construct stabilized arc-shaped air layer on the PET fabric surface to resist high humidity environment. The round belly structures of pea pod-shaped ZnO@POSS and interlaced physical networks assisted by PDMS on the PET fabrics surface served as the crucial roles to capture and retain air, resulting in the capacity of the arc-shaped air layer was significantly larger than other microstructures underwater. The water vapor was prevented from entering the fabric interstices that the self-catalytic hydrolysis behavior of PET macromolecular chains was efficiently restrained, and the strength retention of PET fabric was significantly improved from 45 % to 89 % after accelerated hygrothermal aging test (60 °C, 80 % RH, 600 h). This work represents a simple and effective approach to improve the durability for PET fabrics in high humidity environments.

Study on the effect of multi-factor compound action on long-term tensile performance of GFRP composite pipe and life prediction analysis

In this work, the glass fiber reinforced plastic (GFRP) composite pipes used as sewerage pipes in oil and gas field environments were studied. The accelerated aging experiments were carried out under the simulated environments of three typical oil field media which including circulating air, simulated produced water and standard simulated oil. Scanning electron microscopy (SEM) was adopted to observe the microscopic morphology of the aged GFRP tubes under the three conditions. The microstructural characteristics of the aged tubes and the evolution process of internal defects were also analyzed and evaluated in combination with micro-CT technology. The attenuation pattern of the hoop tensile strength of the aged pipes was measured via the separation disk method, and the service life prediction was carried out based on the Arrhenius theory with the hoop strength as the life index. The results show that the accumulation of aging time and continuous heat input will aggravate the expansion of internal pores and cause the aggregation of small-volume defects into large-volume defects. Especially in the simulated oil environment, which has the highest sensitivity to defects. The maximum porosity reaching 1.5 % and the maximum volume of individual defects exceeding 106 μm3 after aging for 4000 h at 95 °C. The thermal aging process under the three environmental conditions had similar aging characteristics, and interfacial damage of the glass fibers was observed in all of them. The variability of hydrothermal aging is related to the hydrolytic behavior of the glass fibers, which is associated with the progressive dissolution damage of the SiO2 network in the glass fibers, as well as the breaking of silane bonds. Thus, the hydrothermal environment had the most significant effect on the hoop tensile strength decay. Ultimately, 75 % strength retention was taken as the end-of-life indicator. The predicted service life based on the Arrhenius model for the three environments of thermo-oxygen, hydrothermal and simulated oil were 23.5, 23.1 and 28.5 years at 20 °C, and 12.2, 4.9 and 10.3 years at 40 °C, respectively.

An improved coking model for simulating reactive transport phenomena and coking behavior in sucrose hydrolysis

Levulinic acid (LA) holds great significance as a biomass platform chemical in the production of bio-aviation fuel and the utilization of bioenergy. Heterogeneous acid-catalyzed polysaccharide hydrolysis has emerged as a promising method for LA production. Understanding the coupling mechanisms of the physicochemical processes are fundamentally important to optimize the reaction system. In this work, a pore-scale multicomponent reactive transport model based on lattice Boltzmann method was developed to simulate the hydrolysis of sucrose. Considering the significant effect of active sites distribution density on coking formation, an improved coking model was proposed. Systematic investigations of reactive transport and coking behavior were conducted. Simulation results demonstrated that, initial sucrose concentration had a substantial impact on the coking rate of catalyst, when sucrose concentration exceeded 250 mmol/L, the catalyst became fully deactivated before complete hydrolysis of reactant occurred. Furthermore, a marginal benefit was found for the synergistic effect of protons in solution and solid catalysts on sucrose hydrolysis, when proton concentration reached the marginal value of 0.12 mol/L, further increases in proton concentration resulted in only marginal improvements in reaction efficiency. This work underscores the importance of the catalyst morphological character engineering and processes controlled for enhancing overall performance in LA production.

Improved recyclability of the superbase ionic liquid [MTBNH][AcO] used in the lyocell fiber spinning process

In the research of new solvents for cellulose dissolution for textile fiber production, some ionic liquids offer high dissolving capacities making them attractive solvents for lyocell processes. One especially interesting group is superbase carboxylates. However, despite their excellent pulp dissolving abilities and good spinnability properties in a lyocell process, they have been lacking hydrolytic stability, which hinders their recyclability. In this article, a new type of superbase-based ionic liquid, [MTBNH][AcO], is aimed to provide higher hydrolytic stability than its structural relative predecessors. For evaluation of the hydrolysis behavior of [MTBNH][AcO], we have tested the ionic liquid in two sets of recycling experiments. The “blank-experiments” were applied to investigate hydrolytic behavior without the presence of pulp. These values were compared with the results from spinning trials with pulp. It was found that this new ionic liquid is not only more stable than its predecessor [MTBDH][AcO] in terms of hydrolysis but can also dissolve and spin cellulose at lower temperatures. The spun fibers were tested for their textile-physical properties and their performance was comparable to other lyocell fibers.

The Hydrolysis Behavior of Antimony Trichloride and Phase Transformation Mechanism of Hydrolysates with the Effect of Arsenic

The Hydrolysis Behavior of Antimony Trichloride and Phase Transformation Mechanism of Hydrolysates with the Effect of Arsenic

New insights into the destabilization of fat globules in ultra-instantaneous UHT milk induced by added plasmin: Molecular mechanisms and the effect of membrane structure on plasmin action

Residual plasmin activity in whole ultra-instantaneous UHT (UI-UHT) milk causes rapid fat rise during storage, seriously affecting consumers' purchase intentions. In this work, the molecular mechanisms underlying fat destabilization in whole UI-UHT milk by added plasmin were investigated based on the hydrolysis behavior of interfacial proteins. By using SDS-PAGE and peptidomic analysis, we found that the hydrolysis of interfacial proteins by plasmin led to a decrease in the amount and coverage of interfacial proteins and an increase in zeta-potential value, causing the flocculation and coalescence of fat globules. Moreover, the hydrolysis pattern varied in different categories of interfacial proteins by plasmin. In total, 125 peptides in all samples were identified. Plasmin tended to hydrolyze most major milk fat globule membrane (MFGM) proteins into protein fragments (>10 kDa) rather than peptides (<10 kDa). In contrast, peptides derived from caseins were more preferentially identified within a relatively short incubation time. It was the co-hydrolysis of caseins and some major MFGM proteins as anchors that destroyed the stability of MFGM. Furthermore, studies on the effect of trilayer membrane structure remaining at the interface on the hydrolysis rate of major MFGM proteins by plasmin revealed that ADPH and BTN were very sensitive to plasmin action, while PAS 7 was very resistant to plasmin action. Overall, membrane structure reduced the susceptibility of some major MFGM proteins to plasmin and provided protective effects. Therefore, this study provided important insights into the hydrolysis behavior of interfacial proteins in whole UI-UHT milk induced by plasmin.

Hydrolytic degradation behaviors of polylactides/poly(propylene carbonate blends: Monolayers and bulk films

The study investigates the hydrolytic degradation behaviors of blends comprising polylactides (PLA) and poly(propylene carbonate) (PPC) in the form of monolayers and bulk films. PLA is a biodegradable polymer widely used in various applications, while PPC offers unique properties, making it a promising candidate for blend formulations. The research explores the degradation kinetics and mechanical properties under controlled hydrolysis conditions. The finding focuses on the compatibility of PLA and PPC, their degradation mechanisms, and the impact of blend composition on degradation rates. Understanding the hydrolytic behavior of these blends is crucial for designing eco-friendly materials with tailored degradation profiles for diverse applications.

Tuning multiple enzyme-like activities by metal doping for identification and quantitation of antioxidants in cosmetics

Inspired by the hydrolysis behaviors of skin cells, we exquisitely designed and synthesized a class of hydrolase mimics to develop an analytical method that can both identify and quantity antioxidant components in skin-whitening cosmetics, including ascorbic acid (AA) and its glycoside and phosphate derivatives. A series of ultra-thin Cu1-xMnxO2 or Fe1-yMnyO2 with rich acid-base pairs were prepared via chemical deposition and in-situ CuI/FeII self-assembly. H218O and D216O isotopic labeling studies and density function theory (DFT) calculations were adopted to analyze the cleaving sites of ascorbyl phosphate (AAL)/ascorbyl glucoside (AAP) and confirm that H2O was involved in the new bonds. In-situ DRIFT NH3-IR and −TPD further confirmed that the Fe- or Cu-substitution could increase the quantity and strength of Brønsted and Lewis acid sites. A cascade catalytic fluorescence sensor was designed for selective recognition or quantification of AA and its derivatives, which presents ultra-high-precision (≤2.5 %), stability, and selectivity in testing the target ingredients of five cosmetics from the market. Our nanozymes exhibit higher catalytic efficiency of 17.1 s−1 for AA, 8.42 s−1 for AAL, and 3.32 s−1 for AAP, which are 5.6 ∼ 32.8-fold higher than those of their mimic proteases. This work provides a controllable methodology to design hydrolytic nanozymes, which sheds light on biomimetic engineering and paves the way for breakthroughs in cosmetics industrial applications in the future.

Metal-modified CeO2 nanobelts for catalytic oxidation of ethyl acetate: Roles of surface lattice oxygen and hydrolysis behaviors

Based on the comparison of three counterparts [Mg-, Al- and Cu-modified CeO2 nanobelts], it is illustrated that the low-temperature hydrolysis of ethyl acetate (EA) rapidly occurs and the removal of absorbed hydrolyzates (mainly acetates) is considered the rate-determining step. As the temperature increases, the escape of surface lattice oxygen (Os-latt) breaks through the shield of hydrolyzates and promotes the deep oxidation of intermediate products. Additionally, the activated Os-latt also facilitates the C-O bond cleavage in EA by nucleophilic attack. Due to the Os-latt escape, surface metal ions achieve more unsaturated coordinations to absorb the CH3COO– species, leading to competitive adsorption between O2 and hydrolyzates. The Cu modification strengthens the coordination adsorption of CH3COO– species, and the Al modification exhibits a low Os-latt mobility. These factors all contribute to a strong adsorption or accumulation of surface hydrolyzates. Therefore, a favorable ester hydrolysis-oxidation process over CeO2-based catalysts depends not only on excellent Os-latt mobility but also the suitable adsorption capacity of hydrolyzates, such as Mg modification.