Potassium Acetate Research Articles

Stabilization of a single-stranded DNA of adeno-associated virus by inverted terminal repeats.

Parvoviruses have evolved to possess a linear single-stranded DNA (ssDNA) genome ranging from 4 to 6.3kb. Adeno-associated virus (AAV), a member of the Parvoviridae family, contains approximately 5kb of linear ssDNA within its capsid. This ssDNA features two 145-base inverted terminal repeats (ITRs) positioned at each end. ITRs have a T-shaped hairpin secondary structure, which plays a crucial role in viral replication. To investigate the impact of ITRs on ssDNA stability, we conducted a DNA denaturation-reannealing assay in 10 mM magnesium acetate, 50 mM potassium acetate, and 20 mM Tris-acetate buffer at pH7.9. Conventional double-stranded DNA (dsDNA) fragments retain a reannealing capability of over 50% for sizes under 8.8kb, gradually losing this capability as sizes increase; however, dsDNA fragments in rAAV ranging from 0.7 to 6.3kb did not exhibit a reannealing profile. This suggests that the presence of ITRs at both ends hinders annealing between the complementary strands. These results indicate that ITR structures preferentially induce an ssDNA conformation less than 6.3kb in size, and that the stability of AAV ssDNA contributes to the viral life cycle, including processes such as infection, replication, and packaging. Considering the size of parvovirus genomes, it appears that their genomes require reversible flexibility in complementary DNA strands; simultaneously, this adaptability needs to be regulated by specific palindromic ITRs at both ends.

Metal Acetate-Enhanced Microwave Pyrolysis of Waste Textiles for Efficient Syngas Production

The production of waste textiles has increased rapidly in the past two decades along with the rapid development of the economy, the majority of which has been either landfilled or incinerated, resulting in energy loss and environmental pollution. Microwave pyrolysis, which can transform heterogeneous and complex waste feedstocks into value-added products, is considered one of the most competitive technologies for processing waste textiles. However, achieving selective product formation during the microwave pyrolysis of waste textiles remains a significant challenge. Herein, sodium acetate, potassium acetate, and nickel acetate were introduced into waste textiles through an impregnation method as raw materials to improve the pyrolysis efficiency. The optimized process parameters indicated that nickel acetate had the most favorable promotional effect of the three acetates. Notably, the waste textiles containing 1.0% Ni exhibited the highest gas production rate, with the hydrogen-containing combustible gas reaching 81.1% and 61.0%, respectively. Using X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy to characterize the waste textiles before and after pyrolysis, it was found that nickel acetate was converted into metallic nickel (Ni0) during microwave pyrolysis. This active site significantly enhanced the pyrolysis process, and as the gas yield increased, the disorder of the resulting pyrolytic carbon also rose. The proposed Ni0-enhanced microwave pyrolysis mediated by nickel acetate offers a novel method for the efficient disposal and simultaneous resource recovery of waste textiles.

A sustainable approach to enhance biodegradability of recycled LDPE with starch biofillers derived from potato peels and rice husk ash*

ABSTRACT This study investigates the potential of using starch derived from potato peels and rice husks as biofiller for the production of biodegradable plastics. Starch was extracted from potato peels and modified using phthalic anhydride, formamide and potassium acetate to ensure its homogeneous dispersion into the low-density polyethylene (LDPE) matrix. The modified potato peel starch and rice husk ash were characterised using various techniques such as SEM, TEM, FTIR, XRD and were blended with recycled LDPE to enhance its biodegradability for making it an applicable environmental friendly packaging material. The quantity of the biofiller was varied from 4 to 12 g while rice husk ash content was kept constant (0.6 g). The addition of the biofiller reduced the tensile strength, tear strength and transparency of the film with an increase in haze %, weight loss both in garden soil and vegetable waste environment indicating the enhancement in biodegradability of the produced blend. Considering the applicability constrain biodegradable blend containing 20% starch was considered as the best one having tensile strength of approximately 10.42 MPa, tear strength 69.4 N, weight loss percentage of 13.29% in garden soil and 11.34% in vegetable waste when studied for a period of 360 days. Modification of starch has however increased both the mechanical (tensile strength – 12.628 MPa, tear strength – 80.47 N) and biodegradability (weight loss percentage of 15.19% in garden soil and 14.45% in vegetable waste) of the films when studied under the same conditions for the sample containing 30% starch in the matrix.

A Regioselective, One-Pot, Transition-Metal-Free α-Alkylation of Quinone Monoacetals for Various Organic Transformations.

Regioselective reactions of biologically significant quinones are challenging. An unprecedented advancement in quinone monoacetal (QMA) chemistry is proposed for constructing regioselective and less explored α-alkylated QMAs through the Morita-Baylis-Hillman (MBH) reaction. Electrophilic QMAs were transformed to nucleophilic umpolung reagents for aldol-type condensation with several electrophiles. Mechanistic studies reveal that solvent (TFE:water (1:1)) and in situ-generated potassium acetate accelerate the reaction. The ensuing MBH adducts were scalable and underwent several post-synthetic transformations and late-stage functionalization.

Pd‐Catalyzed Cyclization of o‐Iodoanilines with Acrylates or Acrylic Acids: A Convenient One‐Step Route to 2‐Quinolinones

AbstractA convenient and general method for the construction of 2‐quinolinones was developed in this paper. The Pd‐catalyzed cyclization reaction of various o‐iodoanilines with acrylates or acrylic acids proceeded smoothly to produce 2‐quinolinones in 28–>99 % yields. The key to achieve the cyclization reaction is to utilize suitable base, such as potassium pivalate and potassium acetate. Various synthetically useful functional groups, such as halogen atoms, methoxycarbonyl, and nitro groups, remained intact during the reaction. The effects of catalyst and base on this cyclization reaction and kinetic experiments were investigated to understand the aspect of the reaction.

Hybrid Organic-Inorganic Blast Furnace Slag Binders Activated with Alkali Acetates.

Hybrid organic-inorganic binders based on blast furnace slag were produced using sodium (NaAc) or potassium (KAc) acetate as the sole activator, and their properties were compared with those of sodium- or potassium hydroxide-activated slag pastes. The acetate-activated binders showed significantly lower cumulative heat release and extended setting time (∼230 h) than the hydroxide-activated binders. The main reaction products forming in all binders were calcium aluminosilicate hydrate-type gels and a hydrotalcite-like phase, independently of the activator type used. Compressive strengths of the acetate-activated pastes (∼40 MPa at 180 days) were lower than those of the hydroxide-activated binders (∼80 MPa at 180 days). However, the acetate-based binders exhibited superior impermeability and reduced wettability at 28 days, likely due to hydrophobic acetate groups. It is hypothesized that acetates dissociate in water, forming calcium acetate and alkali silicates via a reaction with species dissolving from the slag. This study demonstrates alkali acetates are effective activators for creating hybrid slag-based binders with reduced permeability.

Comparison of potassium catalysts on zeolite sodium A and X in transesterification of palm oil and active species specification

Heterogeneous catalysts consisting of potassium supported on zeolites are active for transesterification, but the effect of zeolite properties is not clearly understood. This work compares catalysts containing 12 wt.% potassium on zeolite sodium A and X (12K/NaA and 12K/NaX) in terms of performance and physicochemical properties. Both catalysts were prepared by ultrasound-assisted impregnation with potassium acetate buffer. 12K/NaA is a better catalyst in transesterification of palm oil, giving a higher biodiesel yield than 12K/NaX in the first run (99.1 ± 0.3 % and 77.9 ± 2.2 %, respectively). From characterization by CO2-TPD, XRD, FTIR, XPS, and SEM-EDS, both catalysts have similar basicity but different dispersion of carbonates and interaction on the zeolites. The 12K/NaA has those species on external surfaces and more monodentate carbonate than 12K/NaX. Ion exchange occurs between potassium ions from the precursor and sodium ions from the zeolite. Moreover, 12K/NaA is more stable, providing higher biodiesel yields in the second and third catalytic cycles.

Thermal activation of kaolinite through potassium acetate intercalation: A structural and reactivity study

Calcined clays have emerged as a suitable alternative to partially replace conventional cement due to their high pozzolanic activity. This study explores a novel activation methodology for kaolinite, aiming to obtain metakaolin at lower temperatures than conventional thermal activation. This methodology involves a prior intercalation stage with potassium acetate (KAc) before thermal activation. The effectiveness of KAc intercalation was assessed through X-ray diffraction (XRD), indicating an intercalation ratio of approximately 90%. Several calcined temperatures were tested in accordance with the thermal behaviour analyzed through thermogravimetric analysis (TGA). Once calcined, the intercalated kaolinites exhibited enhanced reactivity compared to conventional calcined clays in the range between 400 °C to 550 °C, as demonstrated by modified Chapelle and Si/Al availability tests. A comprehensive structural characterization was conducted to facilitate a better understanding of the novel KAc-based metakaolin reactivity through various techniques (XRD, 27Al - 1H MAS NMR, and TGA). This focused on the crystalline changes in the kaolinite structure, the evolution of Al atoms conformation, and the OH behaviour at different thermal activation temperatures. Overall, this study highlights the potential of KAc intercalation as a strategy to obtain higher metakaolin content at lower temperatures than through conventional thermal treatments, offering insights into the development of its potential use as supplementary cementitious materials or alternative cementitious materials precursor.

Equilibrium vapor pressure of aqueous sodium acetate and potassium acetate solutions used as working fluids in frost-free air–source heat pumps at 263–328 K

Aqueous solutions of sodium acetate (CH3COONa) and potassium acetate (CH3COOK) are considered effective alternative heat exchange media for frost-free air–source heat pumps (FFASHPs) owing to the low corrosiveness, low viscosity, and low cost. Equilibrium vapor pressure is the most crucial property that characterizes freezing point and latent heat transfer. However, studies on this property, especially in subzero temperature ranges are scarce. This study was conducted to experimentally investigate the equilibrium vapor pressure of CH3COONa and CH3COOK solutions. The developed apparatus and procedures were based on the static method, and validated by evaluating the vapor pressure of distilled water, n-heptane, and calcium chloride (CaCl2) aqueous solution. Their average absolute deviations were within 1.94%. As the temperature increased from 263 to 328 K and solute concentration increased from 9.27 to 33.81 wt%, 124 data points of the vapor pressure of the CH3COONa and CH3COOK solutions were obtained, ranging from 0.2759 to 13.2608 kPa. Modified Antoine equation and ion interaction (Pitzer) model were established for correlation of the experimental data. The average absolute deviations of the CH3COONa and CH3COOK solutions produced by Antoine equation were 2.08 and 2.48%, respectively. Those produced by Pitzer model further decreased to 1.36 and 1.45% due to the import of osmotic coefficient and the accuracy improvement. Furthermore, according to the experimental and calculation results, the vapor pressure of the CH3COONa solution was lower than that of the CH3COOK solution. Therefore, under the same antifreezing conditions, the CH3COONa solution facilitates latent heat absorption from ambient air, while the CH3COOK solution is conducive to achieve regeneration. The results of this study provide foundational data for the vapor pressure of the two solutions and can promote their application in FFASHPs.

Study on preparation and properties of antifreeze compound road dust suppressant

Open-pit mine pavement dust dries and breaks easily. As such, a composite pavement dust suppressant with good wettability, moisturizing, coagulation, and antifreezing properties in winter was investigated. Monomer screening and orthogonal experiments were conducted, using evaporation rate, permeability rate, viscosity, and freezing point as evaluation indexes. Consequently, a dust suppressant solution is a mixture of glycerol (GLY), sodium dodecylbenzene sulfonate (SDBS), polyacrylamide (PAM), compound propylene glycol (PG), and potassium acetate (PA). The characteristics of the dust suppressant and its interaction mechanism with road dust were measured and analyzed. The results showed that the optimal ratio of the antifreeze-type composite dust suppressant is 3%GLY, 0.30%SDBS, 0.07% PAM, and 50%PG + 10%PA; the contact angle is 27.62°, which can effectively wet coal dust. Moreover, it easily forms hydrogen bonds with water molecules to release free -OH, which increases the oxygen-containing functional groups in the dust. The maximum viscosity is 25.4 mPa·s, and the hydrophobic groups adsorbed on the surface of the dust can condense and agglomerate the dust to form large particles, and effectively inhibit the occurrence of dust. It freezes at − 34.2 ℃, resists a temperature of − 30 ℃ without freezing, and improves dust suppression efficiency and antifreezing effect in cold areas.

The Ninhydrin Reaction Revisited: Optimisation and Application for Quantification of Free Amino Acids.

The ninhydrin reaction is commonly used for the detection of amino acids. However, in the literature, different conditions with respect to the buffer system, its pH and concentration, type of organic solvent, incubation time, and temperature, as well as the concentrations of the reagents, are described. To identify the most suitable conditions, colour development with reagents of varying compositions and different reaction temperatures and times were investigated using asparagine as a model amino acid. Asparagine was selected since it is one of the most abundant free amino acids in many types of samples. The optimal reaction mixture consisted of 0.8 mol L-1 potassium acetate, 1.6 mol L-1 acetic acid, 20 mg mL-1 ninhydrin and 0.8 mg mL-1 hydrindantin in DMSO/acetate buffer 40/60 (v/v) (final concentrations). The best reaction condition was heating the samples in 1.5 mL reaction tubes to 90 °C for 45 min. Afterwards, the samples were diluted with 2-propanol/water 50/50 (v/v) and the absorbance was measured at 570 nm. The proteinogenic amino acids showed a similar response except for cysteine and proline. The method was highly sensitive and showed excellent linearity as well as intra-day and inter-day reproducibility.

Acetate-based ionic liquid immobilized Fe-MIL-101-NH2: A highly efficient heterogeneous catalyst for the conversion of CO2 into oxazolidinones with N-aryl epoxy amines

A novel acetate-based ionic liquid immobilized metal organic frameworks catalyst, Fe-MIL-101-N(Bnme2)OAc, was synthesized using a straightforward ion exchange strategy. Initially, Fe-MIL-101-N(Bnme2)Br was prepared by condensing a quaternary ammonium salt ionic liquid (N(BzBnme2)Br) with Fe-MIL-101-NH2. Subsequently, the Br- ions were exchanged with OAc- ions from potassium acetate to produce the desired catalyst. The morphology, structure and physicochemical properties of the catalyst were comprehensively characterized by XRD, SEM, FT-IR, DRS UV−vis, TGA, BET, and EA, which confirmed both the successful preparation of the catalyst and the integrity of the MOFs framework. The heterogeneous catalyst Fe-MIL-101-N(Bnme2)OAc demonstrated high activity in catalyzing the reaction of N-aryl epoxy amines with CO2 to form oxazolidinone compounds under optimal conditions (80 °C, 8 h, 1 mL of MeCN, 1.0 MPa CO2 and 5 mg catalyst), achieving a yield of up to 99 % with almost no production of the by-product cyclic carbonate. Moreover, this catalyst displayed excellent recyclability and extensive substrate applicability, maintaining its catalytic activity for at least five consecutive uses. Substrates with various substituents also produced the corresponding oxazolidinone products in high yields.

Electrochemical and Cycle Analysis of Water-in-Salt K-Acetate Electrolyte Zn-Ion Batteries Under Commercially-Relevant Conditions

Water-in-salt electrolyte (WiSE) promises high-voltage battery technology with low fire risk. Here we assess potassium acetate (KAc) WiSE for Zn ion batteries under commercially relevant conditions. Rotating disc electrode analysis of WiSE degradation and Zn plating/deplating suggest a solid electrolyte interphase (SEI) layer dominates. Butler-Volmer kinetics and Koutecky-Levich mass-transfer are of secondary importance. Measurements of chemical potential reveal that bulk solvation of H2O (in KAc WiSE or lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) WiSE) is an insignificant process compared to SEI blocking. Zinc cycling in KAc WiSE with practical rates (∼0.3 to 8.0 mA cm−2) and areal capacities (>20 mAh cm−2) shows dendrites are less prominent than in KOH, but the SEI layer suppresses the electrochemical reaction too much for commercial feasibility. Dilution or convection of the WiSE alleviates the SEI blocking effects. Cu substrate shows good Zn adhesion, but Ti, Sn, and Ni show poor adhesion. Cathodes made with Chevrel (Mo6S8) reversibly intercalate Zn2+ to form a novel battery technology when paired with Zn foil, but yield <1.0 V cell voltage. Cathodes made with zinc-containing Prussian blue analogues (ZnHCF or ZnMnHCF) yield a voltage near 2.0 V but don't cycle in the present KAc WiSE formulation. Future research directions for KAc WiSE are proposed, focussing on SEI dynamics and Prussian blue compatibility.

Product regulation of potassium catalyzed pyrolysis of Chinese Baijiu grains: Towards the production of combustible gases and the reduction of tar formation

Engineering-scale conversion and utilization of Chinese baijiu grains (BG) is imperative for the sustainable development of Chinese Baijiu industry. In this study, we developed a facile catalytic pyrolysis of BG using potassium acetate and investigated the proportions of the solid, liquid, and gaseous products at different temperatures and catalyst loadings. Both parameters affected the product proportions, and the highest combustible gas content (83.3 % of total gaseous products) was observed with 1.0 mol/L potassium acetate at 800 °C. The catalyst also affected the proportion of liquid products. In particular, the bio-oil quality improved and the tar content decreased owing to a decrease in long-chain aliphatic acid and ester contents (<10 % of the total liquid products with 1.0 mol/L potassium acetate at 800 °C) and an increase in hydrocarbon content. In addition, the oxygenated groups in the biochar obtained after pyrolysis were bonded to K via K–O bonds, thus making K@biochar a good controlled-release potassium fertilizer. We believe that our catalytic strategy, which has the abovementioned multiple favorable outcomes, could promote commercial-scale valorization of BG.

Utilizing supercritical fluid for efficient preparation of kaolinite nanosheets to enhance Ga(Ⅲ) adsorption

This study explores the efficient preparation of few-layered or monolayered kaolinite (K) nanosheets using supercritical gasification exfoliation technology, aiming to enhance their adsorption capacity for Ga(III). Crystal structure and morphology analysis indicated that the exfoliated K nanosheets maintained an excellent hexagonal lamellar crystal shape, with significantly reduced thickness (∼10 nm) while maintaining an unchanged lateral dimension (400 ∼ 600 nm). The exfoliation mechanism primarily relies on the considerable impact force generated by the rapid expansion of supercritical carbon dioxide (CO2) volume during fast pressure release, which facilitates exfoliation between K layers where the interlayer hydrogen bonds have been disrupted by potassium acetate. Batch adsorption experiments demonstrated a significant improvement in the removal rate of exfoliated K for Ga(III), increasing from 50.66 % to 80.47 % under the conditions of a Ga(III) concentration of 15 mg/L and an adsorbent dosage of 0.4 g/L, attributed to the exposure of numerous active sites. Kinetic and isotherm fitting results indicated a monomolecular adsorption process primarily controlled by chemical adsorption, with a maximum theoretical adsorption capacity of 32.90 mg/g for Ga(III). In multivariate mixed adsorption experiments, exfoliated K exhibited good adsorption selectivity for Ga(III), primarily through chemical adsorption of aluminum hydroxide (Al–OH) functional groups and electrostatic adsorption of silicon oxide (Si–O). Density functional theory (DFT) calculations further demonstrated that the bidentate adsorption coordination of K with Ga(III) exhibits higher stability compared to monodentate adsorption coordination, indicating that the adsorption process is mainly dominated by bidentate adsorption. Consequently, the supercritical gasification exfoliation technology, as a recyclable green process, offers efficient exfoliation of K, holding significance implications for the high-value and high-efficiency utilization of K resources, as well as for establishing a green, low-carbon, and recycling development economic system.

A comparative study of brine solutions as completion fluids for oil and gas fields

Completion fluids play a vital role in well-related processes within the oil extraction industry. This article presents a comprehensive study of the properties and performance of various brine solutions as completion fluids for different well and reservoir conditions. Attributes examined include density, corrosion resistance, temperature stability, compatibility with formation fluids, clay swelling potential and influence on wettability. The research highlights the significance of selecting appropriate completion fluids to optimize well and reservoir operations. Zinc chloride emerges as an excellent option for high density applications, while sodium chloride and potassium formate solutions are ideal for extreme cold conditions. Potassium acetate outperforms calcium chloride and potassium chloride and has excellent pH stability. The compatibility of completion fluids with formation water has been observed to be excellent, with no sedimentation or emulsion formation. Potassium acetate also experiences minimal clay swelling, making it suitable for clay-rich formations. On the other hand, calcium chloride has a higher clay swelling than most of the brines tested, making it less suitable for sandstone formations with a higher clay content than these brines. The research evaluates the water-wetting abilities of completion fluids in carbonate and sandstone formations. Potassium chloride and zinc chloride have the most significant impact in carbonate formations, while potassium acetate and potassium formate excel in sandstone formations. This study provides a comprehensive understanding of completion fluids, facilitating informed decisions that maximize operational efficiency, protect reservoir integrity, and enhance hydrocarbon recovery. The appropriate selection of completion fluids should align with specific well and reservoir conditions, considering the priorities of the application.

Improvements in the Production of Isosorbide Monomethacrylate Using a Biobased Catalyst and Liquid-Liquid Extraction Isolation for Modifications of Oil-Based Resins.

The improved production of a polar curable monomer, isosorbide monomethacrylate (MISD), with methacrylic anhydride (MAAH) as an acyl donor, was performed. A sustainable and cheap catalyst, potassium acetate (CH3COOK), was used for a solvent-free synthesis, requiring only the equimolar amount of reagents (no excess). The production included the quantitative separation of the secondary product, methacrylic acid (MAA), preventing the reaction batch from the purification process (neutralization of MAA), and gaining a usable reagent. The synthesis resulted in a sufficient yield of MISD (61.8%) obtained by the liquid-liquid extraction process (LLE), which is a significant improvement in the process, avoiding the flash chromatography step in the isolation of MISD. The purity of synthesized and isolated MISD via the LLE was confirmed by 1H NMR, MS, and FTIR analyses. The thermal analyses, namely, DSC and TGA, were used to characterize the curability and thermal stability of MISD. The activation energy of MISD's curing was calculated (E a = 94.6 kJ/mol) along with the heat-resistant index (T s = 136.8). The polar character of isosorbide monomethacrylate was investigated in a mixture with epoxidized acrylated soybean oil (EASO). It was found that MISD is entirely soluble in EASO and can modify the rheological behavior and surface energy of EASO-based resins. The apparent viscosity of EASO at 30 °C (ηapp = 3413 mPa·s) decreased with the 50% content of MISD significantly (ηapp = 500 mPa·s), and the free surface energy value of EASO (γS = 42.2 mJ/m2) also increased with the 50% content of MISD (γS = 48.7 mJ/m2). The produced MISD can be successfully used as a diluent and the polarity modifier of curable oil-based resins.

Interfacial toughening for high-efficiency perovskite solar modules

The distinctive benefits of perovskite solar cells, such as their lightweight nature, high flexibility, and ease of deformation, have garnered significant interest. These characteristics make them well-suited for use in portable electronic devices. Nevertheless, a large efficiency gap still exists between laboratory-based small cells and industrial-oriented large-scale modules. One of the primary reasons for the efficiency losses is the limited adhesion at the brittle interface between the perovskite layer and hole transport layer. Herein, potassium acetate is selected to tailor the interface of perovskite/hole transport layer. The presence of potassium acetate between the perovskite layer and hole transport layer has the potential to enhance the p-type perovskite interface. The strengthening of the interface contact could be verified by the utilization of KPFM and DFT calculations. As a result, the charge separation is accelerated associated with the substantial enhancement in Voc from 1.118 V to 1.139 V and the power conversion efficiency of the solar cell has been enhanced, resulting in an increase from 23.76% to 24.81%. Additionally, the perovskite solar module exhibits little loss, with an efficiency of 21.13% with an aperture area of 29.0 cm2.

Influencing factors and identifying precursors in phenolic compounds formation from tobacco extracts pyrolysis

Tobacco extracts is one of the important flavors used in tobacco products, however, some toxic phenolic compounds (phenol, o-Cresol, p-Cresol, catechol, and hydroquinone) are formed during pyrolysis. In this study, the effects of temperature, heating rate, carrier gas atmosphere, and potassium salts on the formation of phenolic compounds by the pyrolysis of tobacco extracts were investigated quantitatively. The characteristics of phenols formation by five phenol-producing precursors (chlorogenic acid, protein, rutin, glucose, and fructose) were further studied. The results showed that with increasing temperature (300–500 ℃), the phenols yields first increased and then decreased, reaching the maximum at about 450 ℃. The yields of phenol and catechol can be significantly decreased by air atmosphere, lower heating rate, and addition of potassium acetate. It was further proved that chlorogenic acid, protein, and rutin are important precursors of phenolic compounds, and chlorogenic acid had the highest phenol yield of 18178.52 μg/g. Moreover, combined with the content of each precursor in the extracts, it was calculated that 83.6 % of the phenol formed at 350 ℃ came from protein and chlorogenic acid, with chlorogenic acid contributing 41.52 %. Potassium acetate decreased the formation of phenol and catechol mainly by acting on chlorogenic acid, inhibiting them by 54.17 % and 57.26 %, respectively; however, it promoted the cresols formation from these precursors to varying degrees during pyrolysis.

Multi-scale measurement of constitutive viscoelastic properties of bituminous composites considering moisture and deicing conditions

The use of salt and chemical deicers can cause significant damage to road infrastructures. This study investigates the impact of different deicers on the viscoelastic properties of mastic and asphalt mixtures, with a focus on characterizing their behavior at varying temperatures and loading frequencies. The samples were subjected to conditioning in solutions of distilled water, salt, Calcium Magnesium Acetate (CMA), and Potassium Acetate (KAc) at 60 °C for 96 h, followed by frequency sweep and dynamic modulus tests at different temperatures and loading frequencies. The results indicate that moisture conditioning with distilled water softens asphalt mixtures and mastic at low loading frequencies, while brine softens the former at low temperatures. Salt's high interaction with mixture aggregates cannot be ignored. CMA's effect on the fatigue behavior of mastic samples is highly dependent on loading frequency, while KAc increases stiffness at intermediate and high temperatures. All the deicers reduce resistance to rutting damage, with CMA having the most negative effect. Both the 2S2P1D and the generalized Maxwell model can well (R2 ≥ 0.90, Se/Sy ≤ 0.35) predict the viscoelastic properties of dry asphalt mixture. However, in the presence of distilled water and the deicers, asphalt mixture viscoelastic properties cannot be predicted according to asphalt mastic characteristics by implementing the homothety method which indicates different effects of distilled water and the deicers on various scales of bituminous composites.