Aqueous Systems Research Articles

From Ions to Crystals: A Comprehensive View of the Non‐Classical Nucleation of Calcium Sulfate

After years of intensive research and numerous important observations, our understanding of the early stages of crystallization is still limited due to the complexity of the underlying processes and their elusive character. In the present work, we provide a detailed view on the nucleation of calcium sulfate mineralization – an abundant mineral with broad use in construction industry – in aqueous systems at ambient conditions. As experimental basis, a co‐titration procedure with potentiometric, turbidimetric and conductometric detection was developed, allowing solution speciation and the formation of crystallization precursors to be monitored quantitatively as the level of nominal (super)saturation gradually increases. The nature and spatiotemporal evolution of these precursors was further elucidated by time‐resolved small‐angle X‐ray scattering (SAXS) and analytical ultracentrifugation (AUC) experiments, complemented by cryogenic transmission electron microscopy (cryo‐TEM) as a direct imaging technique. The results reveal how ions associate into nanometric primary species, which subsequently aggregate and develop anisotropic order by intrinsic structural reorganization. Our observations challenge the common understanding of fundamental notions such as the nucleation barrier or the meaning of supersaturation, with broad implications for mineralization phenomena in general and the formation of calcium sulfate in geochemical settings and industrial applications in particular.

Novel Preparation of Two Oxidized Starch Formulations for Removal of Cr (VI) Ions From an Aqueous Solution

AbstractHexavalent chromium (Cr(VI)) has attracted much attention because it is a harmful pollutant. In this study, acid hydrolyzed hydrothermal double modified starch (AHS) and hydroperoxide oxidized starch (HOS) are prepared from natural starch and used for the reduction of chromium (VI) in aqueous systems. The effects of hydrothermal acidolysis and oxidative modification of starch on the reduction rate of Cr(VI) are discussed, including the changes of solubility, swelling power, particle size, content of straight‐chain starch, and carbonyl/carboxylic group content. The results of response surface methodology (RSM) optimization show that the influence of reaction conditions on the reduction rate of Cr(VI) by NS is as follows: reaction time > initial pH of solution > reaction temperature > starch to Cr(VI) mass ratio; and on the reduction rate of Cr(VI) by AHS and HOS is as follows: initial pH of solution > reaction time > starch to Cr(VI) mass ratio > reaction temperature.

Zinc Chemistries of Hybrid Electrolytes in Zinc Metal Batteries: From Solvent Structure to Interfaces.

Along with the booming research on zinc metal batteries (ZMBs) in recent years, operational issues originated from inferior interfacial reversibility have become inevitable. Presently, single-component electrolytes represented by aqueous solution, "water-in-salt," solid, eutectic, ionic liquids, hydrogel, or organic solvent system are hard to undertake independently the task of guiding the practical application of ZMBs due to their specific limitations. The hybrid electrolytes modulate microscopic interaction mode between Zn2+ and other ions/molecules, integrating vantage of respective electrolyte systems. They even demonstrate original Zn2+ mobility pattern or interfacial chemistries mechanism distinct from single-component electrolytes, providing considerable opportunities for solving electromigration and interfacial problems in ZMBs. Therefore, it is urgent to comprehensively summarize the zinc chemistries principles, characteristics, and applications of various hybrid electrolytes employed in ZMBs. This review begins with elucidating the chemical bonding mode of Zn2+ and interfacial physicochemical theory, and then systematically elaborates the microscopic solvent structure, Zn2+ migration forms, physicochemical properties, and the zinc chemistries mechanisms at the anode/cathode interfaces in each type of hybrid electrolytes. Among of which, the scotoma and amelioration strategies for the current hybrid electrolytes are actively exposited, expecting to provide referenceable insights for further progress of future high-quality ZMBs.

Semi-continuous cultivation of microalgae to treat coal mine effluent in pilot scale: Nutrient removal, biodesalination and fatty acid composition analysis

Coal excavation is associated with discharge of an enormous amount of mine water rich in salt and trace metal ions, which require efficient treatment before use. Considering the potentiality of microalgae for high salt tolerance, salt removal and metallic pollutant removal from aqueous system, present study focuses semi-continuous cultivation of candidate microalgae Chlorella pyrenoidosa (NCIM 2738) in bubble column reactor (BCR) and open raceway pond (ORP) for nutrient supplemented coal mine effluent (NSCME) treatment. In between different hydraulic retention times (HRTs), HRT 6 d provide maximum average biomass productivity of 950 mg L−1 d−1 in BCR and 728.4 mg L−1 d−1 in ORP. HRT 9 d facilitates a maximum lipid content of 1.8 g L ̶ 1 in BCR and 1.4 g L ̶ 1 in ORP. Further, HRT 9 d had the maximum COD removal efficiency (96.5 % in BCR and 94.2 % in ORP) and maximum salinity removal efficiency (93 % in BCR and 92 % in ORP). Fatty acid methyl esters (FAME) characterization highlighted potential biodiesel applicability with cetane number (CN) of 53.94. Energy dispersive X-ray spectroscopy (EDS) revealed an excess amount of salt and metal ions deposition on the surface of harvested microalgae samples. Outdoor large-scale C. pyrenoidosa cultivation can be integrated with coal mine closure plans to meet sustainable development goals (SDGs) 6, 7 and 13.

Construction and Application of a Static Magnetic Field Exposure Apparatus for Biological Research in Aqueous Model Systems and Cell Culture.

With the growth of the quantum biology field, the study of magnetic field (MF) effects on biological processes and their potential therapeutic applications has attracted much attention. However, most biologists lack the experience needed to construct an MF exposure apparatus on their own, no consensus standard exists for exposure methods, and protocols for model organisms are sorely lacking. We aim to provide those interested in entering the field with the ability to investigate static MF effects in their own research. This protocol covers how to design, build, calibrate, and operate a static MF exposure chamber (MagShield apparatus), with instructions on how to modify parameters to other specific needs. The MagShield apparatus is constructed of mu-metal (which blocks external MFs), allowing for the generation of experimentally controlled MFs via 3-axial Helmholtz coils. Precise manipulation of static field strengths across a physiologically relevant range is possible: nT hypomagnetic fields, μT to < 1 mT weak MFs, and moderate MFs of several mT. An integrated mu-metal partition enables different control and experimental field strengths to run simultaneously. We demonstrate (with example results) how to use the MagShield apparatus with Xenopus, planarians, and fibroblast/fibrosarcoma cell lines, discussing the modifications needed for cell culture systems; however, the apparatus is easily adaptable to zebrafish, C. elegans, and 3D organoids. The operational methodology provided ensures uniform and reproducible results, affording the means for rigorous examination of static MF effects. Thus, this protocol is a valuable resource for investigators seeking to explore the intricate interplay between MFs and living organisms. Key features • A comprehensive roadmap, suitable for undergraduate to advanced researchers, to construct an apparatus for in vitro and in vivo experiments within uniform static magnetic fields. • Designed to fit inside standard incubators to accommodate specific environmental conditions, such as with cell culture, in addition to stand-alone operation at room temperature. • Requires two DC power supplies and 3D printer access for the Helmholtz coils, Plexiglass and mu-metal foil for the partition, and a milli/Gaussmeter for calibration. • Requires ordering a custom mu-metal shell from a commercial resource (using provided schematics), where lead times for delivery can vary from 2 to 4 months.

Calculations of mean ionic activity coefficients of copper and manganese salts in aqueous solutions

Accurately predicting the activity coefficients of copper and manganese salts in aqueous solutions is crucial for treating industrial wastewater, and it is of practical interest to calculate the activity coefficients of heavy metals in aqueous solutions using the Equation of State because of its high flexibility and wide range of applicability. This work conducts a modeling study on the mean ionic activity coefficients of copper and manganese salts in aqueous solutions. The thermodynamic framework used in this work is an electrolyte version of the Cubic Plus Association Equation of State (e-CPA). The model's ion-water binary interaction parameters are obtained by regressing the osmotic coefficients and mean ionic activity coefficients in aqueous solutions. The modeling results indicate that the electrolyte Equation of State can satisfactorily correlate the water activity, osmotic coefficients, and mean ionic activity coefficients of copper and manganese salts in aqueous solutions over a wide range of salt concentrations. Among all the systems at 298.15 K, the biggest average relative deviation between calculated and experimental values is within 6.7 % and 2.3 % for the mean ionic activity coefficients and water activity, respectively. Furthermore, this work discusses the impact of ion pairs on the phase equilibrium of aqueous systems from a microscopic mechanism perspective and analyzes and discusses the model's adaptability. The model used in this work can accurately predict the activity coefficients of a variety of copper and manganese salts in aqueous solutions over wide concentration ranges and provides an improved interface for improving the calculation accuracy of the model under high concentration or other complex conditions.

Coalescence of liquid or gel-like DNA-encapsulating microdroplets.

Liquid-liquid phase separation plays a prominent role in the physics of life, providing the cells with various membrane-less compartments. These structures exhibit a range of material properties that, in many cases, change over time. Inspired by this, we investigate here an aqueous two-phase system formed by mixing polyethylene glycol with dextran. We modulate the material properties of the resulting dextran droplets by adding DNA that readily enters the droplets. We find a non-monotonic dependence of the physical properties of the droplets under the imposed ionic conditions.

Biocatalysis with In-Situ Product Removal Improves p-Coumaric Acid Production.

Natural and pure p-coumaric acid has valuable applications, and it can be produced via bioprocessing. However, fermentation processes have so far been unable to provide sufficient production metrics, while a biocatalytic process decoupling growth and production historically showed much promise. This biocatalytic process is revisited in order to tackle product inhibition of the key enzyme tyrosine ammonia lyase. In situ product removal is proposed as a possible solution, and a polymer/salt aqueous two-phase system is identified as a suitable system for extraction of p-coumaric acid from an alkaline solution, with a partition coefficient of up to 13. However, a 10 % salt solution was found to reduce tyrosine ammonia lyase activity by 19 %, leading to the need for a more dilute system. The cloud points of two aqueous two-phase systems at 40 °C and pH 10 were found to be 3.8 % salt and 9.5 % polymer, and a 5 % potassium phosphate and 12.5 % poly(ethylene glycol-ran-propylene glycol) mW~2500 system was selected for in situ product removal. An immobilized tyrosine ammonia lyase biocatalyst in this aqueous two-phase system produced up to 33 g/L p-coumaric acid within 24 hours, a 1.9-fold improvement compared to biocatalysis without in situ product removal.

Phase behavior of aqueous two-phase systems formed with cholinium-based magnetic ionic liquids: Experimental insights and theoretical correlations

In this work, three cholinium-based MILs were synthesized, characterized and successfully applied to construct the magnetically responsive aqueous two-phase system (ATPs). This ATPs combined the advantages of ILs and magnetic responsiveness, and showed great potential in the field of extraction and separation. Phase behavior for the magnetic ionic liquid aqueous two-phase systems (MIL-ATPSs) containing [N 1 1n 2OH] [TEMPO-OSO3] + salts + water was investigated experimentally at different temperatures. Merchuk equation was adopted to fit the experimental binodal data with satisfactory correlation performances. The effects of the structure of MILs, temperature and types of salts on the phase behavior were evaluated. Investigation on the phase separation mechanism showed that the phase formation was affected by the structure and viscosity of MILs. The salting-out effect is recognized as the major force for phase separation, which is closely related to the Gibbs free energy of hydration (ΔhydG) and entropy of hydration (ΔhydS) of salts. In addition, a larger biphasic area was obtained by increasing the temperature, indicating the phase separation process was endothermic and entropically driven. The binodal curve at different temperature confirms that this MIL-ATPs has low critical solution temperature (LCST) phase transition behavior. All these experimentally measured data and the theoretical correlations can provide meaningful and valuable information that may promote further research and application.

Preparation of starch-based oral fast-disintegrating nanofiber mats for astaxanthin encapsulation and delivery via emulsion electrospinning

Developing green and efficient delivery systems to promote bioavailability of bioactive ingredients is a sustained demand in food industry. In this work, the astaxanthin (AST)-loaded starch-based fast-dissolving nanofibers with core-shell structure were prepared by emulsion electrospinning technique without using any organic solvent. To load water-insoluble AST in hydrophilic octenyl succinic anhydride starch (OSAS)/polyvinyl alcohol (PVA) nanofiber matrices, AST-loaded nanoscale emulsions (212.19 ± 5.63 nm) with high encapsulation efficiency (91.54 ± 0.14 %) were prepared as a precursor for emulsion electrospinning, using OSAS/PVA aggregates as an emulsifier. The core-shell structure of nanofibers was revealed by the Transmission electron microscopy (TEM), with average diameter of 509.58 ± 12.77 nm, and 88.64 ± 0.49 % for AST were effectively encapsulated in core layer. Nanofiber mats exhibited high encapsulation efficiency (85.11 ± 1.53 %) and excellent storage stability over 7 d. Meanwhile, amorphous transformation of AST enabled it possess higher water solubility, bioaccessibility, and antioxidant properties (97.72 ± 2.17 %) than free AST in aqueous system. The results demonstrated that the green, nontoxic, and biodegradable nanofiber mats prepared by emulsion electrospinning successfully realized the encapsulation and delivery of AST, with broad application prospects in the food and pharmaceutical fields.

Spent Tea Leaves as an Adsorbent Material: Preparation, Characterization, and Application

The adsorption of Congo Red (CR) on the surface of Spent Tea Leaves (STL) was evaluated in an aqueous system. The study was carried out for the establishment of a standard wastewater treatment method that would remove reactive dyes by employing spent tea leaves as a bio-adsorbent. The effect of various parameters like amount of adsorbent, contact time, concentration of dye, and pH on the adsorption was studied. The adsorption capacity was monitored with a UV-visible spectrophotometer. The maximum adsorption of dye was observed at adsorbent mass of 3.5g /100 mL, at 8×10-5 M CR concentration, at pH = 9.72 and 50 minutes of contact time. The experimental results suggest that the adsorption of CR on the surface of STL is an exothermic process. The adsorption of CR on STL is found to follow pseudo first order kinetics. Based on the findings, it’s feasible to draw the conclusion that spent tea leaves would be a better adsorbent for the removal of reactive dyes from the wastewater.

Effect of annealing on the MnO2 cathodes for high-performance aqueous Zn-ion batteries

Zinc ion batteries (ZIBs) are increasingly prominent due to their cost-effectiveness, abundance, environmental safety, mature processing methods, high volumetric energy density, and compatibility with aqueous electrolytes. However, a significant challenge lies in finding a suitable cathode material with high capacity and structural stability. Manganese dioxide (MnO2) is a promising candidate for ZIB cathodes in aqueous systems, surpassing other metal oxides in potential. However, MnO2 cathodes encounter challenges, including rapid capacity degradation and limited cyclic stability. Enhancing the structural stability of host materials during intercalation presents a significant avenue for increasing cathode capacity. In this study, we employed a hydrothermal method to synthesize MnO2, followed by annealing in an argon atmosphere at 300 °C for 4 h for MnO2-300 and 400 °C for 2 h for MnO2-400 to bolster its structural integrity. The properties of annealed samples MnO2-300 and MnO2-400 are compared with pristine samples (MnO2-P). Initially, XRD analysis is conducted to compare their structures, followed by a comparison of electrochemical properties, including Cyclic Voltammetry (CV) and charge-discharge analysis. MnO2-400 exhibits a higher initial capacity (149.3 mAhg−1 at 0.1 Ag-1) than MnO2-300 (129.0 mAhg−1 at 0.1 Ag-1) and MnO2-P (107.9 mAhg−1 at 0.1 Ag-1). An extended cycling test of up to 500 cycles also indicates that annealing MnO2 in an Ar atmosphere enhances structural stability and capacity compared to the unannealed sample.

Robust ZIF-8 based superhydrophobic coating with anti-icing, anti-corrosion, and substrate universality

The design of superhydrophobic materials based on zeolite imidazolate frameworks (ZIF) has attracted considerable attention due to their exceptional chemical stability, high specific surface area, and environmental friendliness. However, research in the fields of anti-corrosion and anti-icing remains in its infancy, and the mechanical stability of reported ZIF-based superhydrophobic surfaces is generally poor. In this study, we synthesized ZIF-8@PDA materials in an aqueous system and followed with stearic acid (STA) modification to achieve low surface energy, resulting in ZIF-8@PDA@STA. Subsequently, we applied a spray-coating method to sequentially construct WPU and ZIF-8@PDA@STA layer on aluminum alloy substrates, achieving a ZIF-8@PDA@STA/WPU superhydrophobic coating with exceptional mechanical stability. This coating retained its superhydrophobicity even after 5600 cm of abrasion distance. Furthermore, results from surface wettability, electrochemical and anti-icing tests demonstrated that the coated aluminum alloy exhibited excellent interfacial non-wetting, self-cleaning, anti-fouling, and significantly enhanced corrosion resistance and delayed icing properties. Additionally, the facile preparation of this coating on various substrates facilitates the large-scale application of such materials. The construction of this multifunctional ZIF-8 based superhydrophobic coating is expected to greatly expand the application of ZIF materials across diverse fields.

Synthesis, Characterization, and Interaction Studies of Naphtho‐[2,3]‐furan‐Based Molecules with CTAB as Model Surfactant

AbstractThe synthesis of highly sensitive UV–visible active naphthofuran derivatives, namely naphtho‐[2,3]‐furan‐3‐yl acetate (NF), 9‐bromonaphtho‐[2,3]‐furan‐3‐yl acetate (BNF), 9‐nitronaphtho‐[2,3]‐furan‐3‐yl acetate (NNF), 9‐iodonaphtho‐[2,3]‐furan‐3‐yl acetate (INF), and naphtho‐[2,1‐b]‐furan‐4‐carboxylic acid (ONF) as solvatochromic molecules, was carried out through multistep synthetic approach. These molecules possess different substituents that tend to form micelles in cetyl trimethylammonium bromide (CTAB) aqueous system. During the micellization process, the absorption spectrum of the synthesized molecule exhibits sensitivity towards the polarity of the environment, which affects the critical micelle concentration (cmc) of CTAB. This study demonstrates that synthesized molecules can be used for estimating solvent polarity and cmc.

Highly enhanced fluoride removal from aqueous systems via solvent extraction utilizing trialkyl phosphine oxide as an efficient extractant

Solvent extraction (SX) has been recognized as an efficient approach for the large-scale removal of impurities, demonstrating considerable potential for fluoride extraction in industrial applications. However, existing fluoride extraction methods typically require the incorporation of additives to form complexes with fluoride for its removal. Due to the excessive additive requirements for efficient fluoride removal, these methods inevitably result in secondary contamination of feed solution, necessitating additional purification efforts to remove them. In this study, four extractants (trioctyl amine, tributyl phosphate, trioctyl phosphate, and trialkyl phosphine oxide (TRPO)) were investigated for fluoride removal via hydrogen bonding with hydrofluoric acid (HF). Various parameters, including the concentrations of extractants and stripping agents, pH values, extraction time, and temperature were initially optimized. It was found that TRPO exhibits the highest extraction efficiency for HF, with a single-stage extraction rate exceeding 70 %. Complete fluoride removal (> 99.9 %) was achieved through a consecutive four-stage extraction process. Further experiments, including maximum loading and slope analysis, combined with FT-IR and 19F NMR characterization, and DFT calculations elucidate the mechanism of the extraction. The transfer of HF into the organic phase is accomplished by the formation of a 1:1 hydrogen-bonded complex with TRPO. The loaded fluoride in the organic phase can be easily stripped by a base to get a fluoride salt. This study paves the way for the construction of novel SX systems to remove fluoride as HF.

Biochar from Malt Residue: Toward a Circular Economy for Sustainable Fluoroquinolone Removal in Aqueous Systems

Malt bagasse holds potential as a high-value material, contributing to a circular economy. Biochars were synthesized via pyrolysis (PC-500) and hydrothermal carbonization (HC-150), with one-pot activation using phosphoric acid. Additionally, PC-500 activated with H3PO4 was synthesized for comparison. Various analytical methods were used to characterize the materials. The PC-500 and PCA-500 samples exhibited higher degrees of carbonization, whereas the HC-150 sample retained its functional groups more effectively. Biochars showed higher porosity than biomass, with microspheres present in HC-150. Evaluations were conducted on the removal of fluoroquinolones from water using biochars. Maximum removal efficiency was obtained at pH 8, favoring neutral fluoroquinolone species with a Brønsted acid-base nature. The experimental outcomes were further rationalized by the computational calculation of the physicochemical properties of the adsorbates, in analogy with the structural activity relationship approach in medicinal chemistry. The pseudo-second-order kinetic model proved to be the most suitable for fitting the experimental data, while the Langmuir model effectively described the adsorption isotherms. Ciprofloxacin, enrofloxacin, and norfloxacin showed maximum adsorption capacities (qmax) of 95, 164, and 99mgg-1, respectively, when HC-150 was used. On the other hand, with PC-500, qmax of 57, 12, and 20mgg-1 were obtained for ciprofloxacin, enrofloxacin, and norfloxacin, respectively. Although PCA-500 enhanced adsorption capacity compared to PC-500, the qmax remained lower than the results obtained with HC-500, measuring at 51, 102, and 95mgg-1. These findings emphasize malt bagasse biochar as a viable adsorbent.

Eggshell-Derived Fe-Mg Particles and Hydroxyapatite for Removal of Tetracycline and Metronidazole from Aqueous Systems

Eggshell-Derived Fe-Mg Particles and Hydroxyapatite for Removal of Tetracycline and Metronidazole from Aqueous Systems

Removal of Dyes from Waste Water Using Low‐Cost Adsorbents

AbstractThe principal objective of this article is a thorough analysis of the usage of inexpensive adsorbents to eliminate dyes from different aquatic environments. Dyes, commonly employed in industries—textiles, pharmaceuticals, and food, pose a significant environmental concern due to their persistence and potential toxicity. In response, researchers have explored the efficacy of low‐cost adsorbents (LCAs) as sustainable and economical alternatives for dye elimination. An overview of the environmental effects of dye contamination and the difficulties in using traditional dye removal techniques is given at the outset of the paper. It then delves into the diverse range of LCAs, including agricultural by‐products, waste materials, and natural substances, that have shown promise in adsorbing and eliminating dye contaminants. Examples of such adsorbents include activated carbon (AC) derived from agricultural residues, bio‐adsorbents from various plant materials, and industrial by‐products with inherent adsorption properties. Key mechanisms involved in the adsorption process, such as surface chemistry, pore structure, and electrostatic interactions, are elucidated to offer a fundamental understanding of the sorption capabilities of these materials. This comprehensive review consolidates the current knowledge on dye removal utilizing LCAs, offering insights into the challenges, advancements, and future directions in this environmentally significant field. The findings underscore the potential of harnessing readily available, sustainable materials as effective sorbents for mitigating the adverse impacts of dye pollutants in aqueous systems. The adsorption capacity is comparable to supplementary adsorbents suggested for the removal of dyes. The widely accessible adsorption properties of basic and acidic dyes do not significantly differ from one another.

Solid-liquid phase equilibria in the aqueous system containing the chlorides of potassium, ammonium, and calcium at 298.2, 323.2, and 348.2 K

In order to obtain the crystalline forms of the salts of the potassium, ammonium, calcium coexisting chloride system, the phase equilibria relationship of quaternary system K+, NH4+, Ca2+//Cl–-H2O at 298.2, 323.2, and 348.2 K was studied by isothermal dissolution equilibrium method. The solubility and density of equilibrium liquid phases of the system were experimentally determined; X-ray powder diffractometer was used to determine the compositions of the equilibrium solid phase at the quaternary invariant point. It is found that the quaternary system is a complex system at these three temperatures. The phase diagram at 298.2 K consists of three invariant points, seven univariate curves and five crystalline phase regions, forming the solid solutions (NH4Cl)x(KCl)1–x and (KCl)x(NH4Cl)1–x; while at 323.2 and 348.2 K the phase diagram consists of five invariant points, eleven univariate curves and seven crystalline phase regions, the double salts (KCl·CaCl2) and (2NH4Cl·CaCl2·3H2O), solid solutions (KCl)x(NH4Cl)1–x and (NH4Cl)x(KCl)1–x were formed. Among them, the crystalline phase region of solid solution (KCl)x(NH4Cl)1–x is the largest at three temperatures, indicating that it is the easiest to crystallize in this system. Comparing the phase diagrams of the quaternary system at 298.2, 323.2, and 348.2 K, it can be seen that the crystalline form of CaCl2 changes with the increase of temperature: CaCl2·6H2O at 298.2 K, CaCl2·2H2O at 323.2 and 348.2 K. From 323 to 348 K, the crystalline phase regions of (KCl·CaCl2) and (2NH4Cl·CaCl2·3H2O) increased gradually.

Chitosan-curcumin conjugate prepared by one-step free radical grafting: Characterization, and functional evaluation

Curcumin (Cur) is a naturally hydrophobic polyphenol, and it has a wide range of physiological functions. But the practical application of Cur is constrained by its low water solubility and poor stability. To improve these deficiencies of Cur, a novel Cur derivative (CS-Cur) was prepared by grafting chitosan (CS) with Cur through a one-step reaction of a free radical-mediated redox system. A series of characterizations provided evidence that the grafting of CS with Cur was successful. The obtained CS-Cur showed lower crystallinity and thermal properties than CS and Cur. After grafting, the water solubility of CS-Cur was found to be 9.76±2.45 g/L and greatly improved. Meanwhile, the CS-Cur showed good photothermal stability, antioxidant activity, and photodynamic antibacterial activity in an aqueous solution, and it had good in vitro biosafety. This provides an idea for the design and synthesis of novel highly water-soluble Cur derivatives and also improves the practical application of Cur in aqueous systems.