[Investigation of exogenous stimulus effect on the interaction of CdSe/ZnS quantum dots/TiO2 nanocomposites with human serum albumin by resonance light scattering].

The interaction between CdSe/ZnS(quantum dots)/TiO2 nanocomposites and human serum albumin(HSA) was investigated by resonance light scattering (RLS) spectroscopic methods under approximate physiological conditions. Much important information of the interaction between CdSe/ZnS(Quantum Dots)/TiO2 nanocomposites and HSA was obtained by studying comprehensively the Exogenous influence factors of nanocomposites concentration, pH, NaCl concentration, reaction temperature, detection time, coexisting ions, surfactants, sequence of adding to the sample etc. It was showed that the new formation of complex system is likely to enhance the protein hydrophobic cavity and tend to focus the hydrophobic interface in aqueous solution, resulting in strengthening the intensity of resonance light scattering; Also it is very sensitive to the changes in the pH value in the system; The sensitivity of I(RLS) in system can be increased by the appropriate NaCl concentration; The value of IRLS in system would be changed with the change in the concentration of coexisting ions; The value of I(RLS) in system is basically stable when the reaction time reaches 5 min; The value of I(RLS) in system is not exactly the same with a surfactant, and strong electrostatic interaction has occurred between oppositely charged surfactant and nano composites; It is obvious that the value of I(RLS) in complex system is affected by the sequence of adding to sample; It has the incomplete monotonically increasing trend with the changes in temperature. The information is useful for providing theoretical supporting for the mechanism of interaction between nanomaterials and bio-macromolecule, and for understanding the biocompatibility and safety of nano-materials.

Removal of diclofenac sodium from aqueous solution using different ionic liquids functionalized tragacanth gum hydrogel prepared by radiation technique.

Diclofenac sodium (DCF) was reported as an important emerging environmental pollutant and its removal from wastewater is very urgent. In this study, different alkyl substituted ionic liquids (1-alkyl -3-vinyl- imidazolium bromide [CnVIm]Br, n = 4, 6, 8, 10, 12) functionalized tragacanth gum (TG-CnBr) are prepared by radiation induced grafting and crosslinking polymerization. The adsorption behaviors of ionic liquids functionalized tragacanth gum for diclofenac sodium from aqueous solutions are examined. The adsorption capacity of TG-CnBr for diclofenac sodium increases with the increasing of alkyl chain length of the imidazolium cation and the hydrophobicity of the hydrogels. The maximum adsorption capacity by TG-C12Br for diclofenac sodium at 30, 40 and 50 °C were 327.87, 310.56 and 283.29 mg/g, respectively. The adsorption of TG-C12Br towards diclofenac sodium was little decreased with NaCl increasing. The removal efficiency was still remained 94.55 % within 5 adsorption-desorption cycles by 1 M HCl. Also, the adsorption mechanism including electrostatic attraction, hydrophobic interaction, hydrogen bonding, and π - π interaction was proposed.

Efficient removal of p-nitrophenol from water by imidazolium ionic liquids functionalized cellulose microsphere.

Removing p-nitrophenol (PNP) from water resources is crucial due to its significant threat to the environment and human health. Herein, imidazolium ionic liquids with short/long alkyl chain ([C2VIm]Br and [C8VIm]Br) modified cellulose microspheres (MCC-[C2VIm]Br and MCC-[C8VIm]Br) were synthesized by radiation method. To examine the impact of adsorbent hydrophilicity on adsorption performance, batch and column experiments were conducted for PNP adsorption. The MCC-[C2VIm]Br and MCC-[C8VIm]Br, with an equivalent molar import amount of ionic liquids, exhibited maximum adsorption capacities of 190.84 mg/g and 191.20 mg/g for PNP, respectively, and the adsorption equilibrium was reached within 30 min. Both adsorbents displayed exceptional reusability. Integrating the findings from XPS and FTIR analyses, and AgNO3 identification, the suggested adsorption mechanism posited that the adsorbents engaged with PNP through ion exchange, hydrogen bonds and π-π stacking. Remarkably, the hydrophobic MCC-[C8VIm]Br exhibited superior selectivity for PNP than the hydrophilic MCC-[C2VIm]Br, while had little effect on adsorption capacity and rate. MCC-[C8VIm]Br-2 with high grafting yield increased the adsorption capacity to 327.87 mg/g. Moreover, MCC-[C8VIm]Br-2 demonstrated efficient PNP removal from various real water samples, and column experiments illustrated its selective capture of PNP from groundwater. The promising adsorption performance indicates that MCC-[C8VIm]Br-2 holds potential for PNP removal from wastewater.

Selective recovery of Re(VII) by nucleobases functionalized cellulose microspheres from the simulated uranium ore leaching solution.

From a practical standpoint, it is still challenging to develop adsorbents with high adsorption capacity and outstanding selectivity for rhenium in uranium ore leaching solution. In this study, in order to explore the structure-property relationship, four nucleobases (Adenine, Guanine, Hypoxanthine and Xanthine) were used as functionalization reagents to modify cellulose (MCC-g-GMA-A, MCC-g-GMA-G, MCC-g-GMA-H and MCC-g-GMA-X) via radiation method. The effect of the type of nucleobases on the adsorption performance was evaluated by batch and dynamic experiments. The order of maximum adsorption capacity was MCC-g-GMA-A (194.0 mg g-1) > MCC-g-GMA-G (123.4 mg g-1) > MCC-g-GMA-H (45.59 mg g-1) > MCC-g-GMA-X (23.43 mg g-1), which was associated with the category of nitrogen-functional groups. Different nitrogen-containing functional groups have different degrees of protonation, which leads to differences in the interaction of the adsorbent with Re(VII). Notably, the adsorbents were able to selectively capture trace Re(VII) from the simulated uranium ore leaching solution. The FT-IR, XPS analyses, DFT theoretical calculations exhibited that the adsorption mechanism of nucleobases functionalized cellulose microspheres and Re(VII) was electrostatic interaction. MCC-g-GMA-A and MCC-g-GMA-G exhibited excellent selectivity towards Re(VII), which are potential adsorbents for Re(VII) recovery in uranium ore leaching solutions.

Facile fabrication of Artemisia sphaerocephala krasch gum hydrogels by radiation induced cross-linking polymerization and enhanced ultrahigh adsorption for methylene blue.

Although Artemisia sphaerocephala krasch gum (ASKG) has attracted growing attention in the field of medical engineering and food industries, however, there are few studies on the gelation of ASKG. In this paper, acrylic acid modified ASKG hydrogels were prepared by radiation induced grafting, cross-linking and polymerization technique for the first time. The semi-IPN structure was prepared by the cross-linked ASKG network and poly-AAc dispersed within the network. The effects of the adsorbed dose on the swelling ratio and gel fraction were investigated. The different acrylic acid content modified ASKG hydrogels (ASKGAAc1 and ASKGAAc2) for methyl blue (MB) adsorption were investigated, and the ASKG hydrogels was also studied for comparison. The influence of pH, contact time, initial concentration, temperature, ion strength on MB adsorption were tested. The results showed that acrylic acid can promote the formation of hydrogel and greatly enhanced the adsorption of ASKG. The adsorption isotherms were well obeyed the Langmuir model, and the maximum adsorption capacity for MB of ASKG, ASKGAAc1 and ASKGAAc2 were 571.43, 1517.8 and 1654.9 mg/g, respectively. Moreover, the MB adsorption by ASKG based hydrogels was exothermic, spontaneous, and more favorable at lower temperature. Furthermore, the adsorption-desorption experiments demonstrated a good reusability of these hydrogels.

Research on irradiated food status and consumer acceptance: A Chinese perspective.

China is currently the world's largest producer of food irradiation. Despite the long-standing (about 100 years) evidence supporting the safety of food irradiation, consumers' acceptance of irradiated foods remains limited. This study aimed to investigate the development of food irradiation in China and identify the barriers that keep consumers away from irradiated foods. This was accomplished by exploring the relevant policies of food irradiation, the size and distribution of irradiation facilities in China, and analyzing their relationships between consumer characteristics and the acceptance of irradiated food. To achieve these objectives, we conducted an online survey of participants from Hubei, China (N = 264). The results reveal that irradiation facilities are mainly distributed in large coastal cities such as the Bohai Bay, the Yangtze River Delta, and the Greater Bay Area. Furthermore, the study identified that consumer' acceptance of irradiated food is directly related to their level of understanding. Approximately 22% of the sampled consumers reported that they would not accept that they have consumed irradiated food and most of them (41%) stated that they would not purchase irradiated food if they were aware of buying irradiated food. Specifically, consumers expressed discomfort with consuming irradiated food under unknown circumstances. This trend is more prevalent among female, low-educated, and older consumers, with 40% of the sampled population indicating that they would not buy irradiated food. Given the strong correlation between knowledge and acceptance of irradiated foods, the study suggests that policy reform should prioritize enhancing the understanding of irradiated food, particularly among female, low-educated, and older consumers.

Selective and Effective Gold Recovery from Printed Circuit Boards and Gold Slag Using Amino-Acid-Functionalized Cellulose Microspheres.

The hydrometallurgical recovery of gold from electronic waste and gold slag is a hot research topic. To develop a cost-effective and environmentally friendly adsorbent for gold recovery, four types of amino-acid (arginine, histidine, methionine, and cysteine)-functionalized cellulose microspheres were prepared via a radiation technique. The adsorption performance of the amino acid resins toward Au(III) ions was systematically investigated by batch experiments. The amino acid resins could absorb Au(III) ions at a wide pH range. The adsorption process was followed by the pseudo-second-order model and Langmuir model. The theoretical maximum adsorption capacity was calculated as 396.83 mg/g, 769.23 mg/g, 549.45 mg/g, and 636.94 mg/g for ArgR, HisR, MetR, and CysR, respectively. The amino acid resins could effectively and selectively recover trace Au(III) ions from the leaching solutions of printed circuit board and gold slag waste. Lastly, the mechanism underlying amino acid resin's Au(III) ion recovery capability was investigated by FTIR, XRD, and XPS analyses. This work describes a series of cost-effective gold adsorbents with excellent selectivity and adsorption capacity to boost their practical application.

A comparative study of immobilizing ammonium molybdophosphate onto cellulose microsphere by radiation post-grafting and hybrid grafting for cesium removal.

Ammonium molybdophosphate (AMP) exhibits high selectivity towards Cs but it cannot be directly applied in column packing, so it is necessary to prepare AMP-based adsorbents into an available form to improve its practicality. This work provided two AMP immobilized cellulose microspheres (MCC@AMP and MCC-g-AMP) as adsorbents for Cs removal by radiation grafting technique. MCC-g-AMP was prepared by radiation graft polymerization of GMA on microcrystalline cellulose microspheres (MCC) followed by reaction with AMP suspension, and MCC@AMP was synthesized by radiation hybrid grafting of AMP and GMA onto MCC through one step. The different structures and morphologies of two adsorbents were characterized by FTIR and SEM. The adsorption properties of two adsorbents against Cs were investigated and compared in batch and column experiments under different conditions. Both adsorbents were better obeyed pseudo-second-order kinetic model and Langmuir model. MCC-g-AMP presented faster adsorption kinetic and more stable structure, whereas MCC@AMP presented more facile synthesis and higher adsorption capacity. MCC@AMP was pH independent in the range of pH 1-12 but MCC-g-AMP was sensitive to pH for Cs removal. The saturated column adsorption capacities of MCC@AMP and MCC-g-AMP were 5.4 g-Cs/L-ad and 0.75 g-Cs/L-ad in column adsorption experiments at SV 10 h-1. Both adsorbents exhibited very high radiation stability and can maintain an adsorption capacity of >85% even after 1000 kGy γ-irradiation. On the basis, two AMP-loaded adsorbents possessed promising application in removal of Cs from actual contaminated groundwater. These findings provided two efficient adsorbents for treatment of Cs in radioactive waste disposal.

Highly photocatalytic electrospun Zr/Ag Co-doped titanium dioxide nanofibers for degradation of dye.

Photodegradation has attracted much attention in wastewater treatment owing to its nontoxicity, high efficiency, and mild reaction conditions. Recently, Zr/Ag co-doped titanium dioxide (TiO2) nanoparticles have been synthesized and showed high photocatalytic activity for dye, but these nanoparticles tend to aggregate together, leading to reduced catalytic sites, which is disadvantageous for their practical application. Therefore, Zr/Ag-co-doped TiO2 nanofibers were prepared using an electrospinning method. For comparison, TiO2 nanofibers and Zr-doped TiO2 nanofibers were also fabricated. The synthesized catalysts were characterized by X-ray diffraction, UV-visible absorption spectroscopy, diffuse reflectance spectroscopy, scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy, zeta potentials, photoluminescence, and electrochemical impedance spectroscopy. Compared with TiO2 nanofibers and Zr-doped TiO2, Zr/Ag co-doped TiO2 nanofibers have significantly enhanced photocatalytic activity for Congo red owing to the synergetic effects of Zr, Ag, and Ti. The photodegradation of Congo red followed a pseudo-first-order kinetic model. The optimal Zr/Ag-co-doped TiO2 nanofibers with 2 wt% Ag and a mass ratio of ZrO2 to TiO2 of 1:9 exhibits the best photocatalytic activity and the corresponding kinetic constant of 0.0405 min-1 is 12 times higher than that of TiO2 nanofibers. This work will provide data and a technology base for the synthesis of future materials with high photocatalytic activity.

Radiation grafting of dimethylaminoethyl methacrylate on cotton linter and subsequent quaternization as new eco-friendly adsorbent for phosphate removal.

Quaternary ammonium salt type cotton linter (QCL) was synthesized by radiation grafting of dimethylaminoethyl methacrylate (DMAEMA) onto cotton linter and subsequent quaternization. Batch and column adsorption experiments were used to evaluate the adsorption behaviors of the QCL for phosphate. The adsorption kinetics of QCL for phosphate were well obeyed pseudo-second-order mode. The adsorption isotherms were well fitted by Langmuir, Temkin, and Dubinin-Radushkevich model. Column experiments showed that the breakthrough curves were dependent on the inlet concentration and flow rate but independent on space velocity. Moreover the QCL can be effectively regenerated for further repeated use at least 10 cycles. And QCL exhibited good selective adsorption for phosphate. Such high adsorption and desorption efficiency of QCL made it employing for phosphate adsorption in practical application.

Facile preparation of L-cysteine-modified cellulose microspheres as a low-cost adsorbent for selective and efficient adsorption of Au(III) from the aqueous solution.

A facile method to synthesize adsorbent based on cellulose modified by amino acid was developed. The novel L-cysteine-functionalized adsorbent for Au(III) recovery was synthesized via radiation grafting technique. Glycidyl methacrylate (GMA) was grafted on the surface of microcrystalline cellulose microsphere (MCC); next, ring-opening reaction was performed to immobilize L-cysteine. The adsorption abilities of the adsorbent (CysR) were tested. Batch experiments suggested that the maximum adsorption capacity of Au(III) is 714.28 mg/g calculated by Langmuir model. The adsorption kinetic data was followed by pseudo-second-order model. CysR showed excellent selectivity for Au(III) even the concentration of competing ions was all ten times than that of Au(III). The column experiments revealed that Au(III) could be efficiently adsorbed by CysR competition with equal amounts of Ni(II) and Zn(II). Moreover, XPS analysis demonstrated that the adsorbed Au(III) was reduced to Au(I) and Au(0). The adsorption performance certified that CysR was a promising adsorbent for Au(III) recovery.

Fabrication of Cotton Linter-Based Adsorbents by Radiation Grafting Polymerization for Humic Acid Removal from Aqueous Solution.

Two kinds of cotton linter-based adsorbents were synthesized by grafting dimethylaminoethyl methacrylate (DMAEMA) on cotton linter via radiation grafting polymerization, followed by further quaternization (QCL) or protonation (PCL). The effect of radiation dose and monomer concentration on grafting yield was optimized. The synthesized adsorbents were characterized by Fourier transform infrared spectrometry (FT-IR), Thermogravimetric Analysis (TGA), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The adsorption behaviors of the two adsorbents toward humic acid (HA) were investigated and discussed. pH effect studies showed that QCL was pH-independent, whereas PCL was just suitable for HA adsorption with pH < 6. The adsorption kinetics of the PCL and QCL adsorbent for HA removal were better described by pseudo-second-order kinetic mode and reached equilibrium in 40 min. The adsorption isotherms of the PCL and QCL adsorbent were well fitted with both Langmuir and Freundlich isotherm models, for which adsorption capacity reached 250 mg/g and 333 mg/g at pH 6, respectively. XPS analysis revealed the ratio of two amino group species at different pH, suggesting that the interaction mechanism of the adsorbent and HA was electrostatic adsorption.

Radiation Synthesis of Pentaethylene Hexamine Functionalized Cotton Linter for Effective Removal of Phosphate: Batch and Dynamic Flow Mode Studies.

A quaternized cotton linter fiber (QCLF) based adsorbent for removal of phosphate was prepared by grafting glycidyl methacrylate onto cotton linter and subsequent ring-opening reaction of epoxy groups and further quaternization. The adsorption behavior of the QCLF for phosphate was evaluated in a batch and column experiment. The batch experiment demonstrated that the adsorption process followed pseudo-second-order kinetics with an R2 value of 0.9967, and the Langmuir model with R2 value of 0.9952. The theoretical maximum adsorption capacity reached 152.44 mg/g. The experimental data of the fixed-bed column were well fitted with the Thomas and Yoon-Nelson models, and the adsorption capacity of phosphate at 100 mg/L and flow rate 1 mL/min reached 141.58 mg/g. The saturated QCLF could be regenerated by eluting with 1 M HCl.

Amphoteric Ion Exchange Membranes Prepared by Preirradiation-Induced Emulsion Graft Copolymerization for Vanadium Redox Flow Battery.

A series of poly(vinylidene difluoride)-based amphoteric ion exchange membranes (AIEMs) were prepared by preirradiation-induced graft copolymerization of styrene and dimethylaminoethyl methacrylate in an aqueous emulsion media followed by solution casting, sulfonation, and protonation. The effects of absorbed dose and comonomer concentration on grafting yield (GY) were investigated. The highest GY of 44.5% at a low comonomer concentration of 0.9 M could be achieved. FTIR, TGA, and X-ray photoelectron spectroscopy (XPS) confirmed the successful grafting and sulfonation of the as-prepared AIEMs. Properties of the AIEMs such as water uptake, ion exchange capacity (IEC), ionic conductivity, and crossover behavior of VO2+ ions prepared by this novel technique were systematically investigated and compared with those of the commercial Nafion 115 membrane. It was found that at a GY of 28.4%, the AIEMs showed higher IEC and conductivity, lower permeability of VO2+ ions, and a longer time to maintain open circuit voltage than Nafion 115, which was attributed to their high GY and elaborate amphoteric structure. Consequently, this work has paved the way for the development of green and low-cost AIEMs with good performance for vanadium redox flow battery applications.

Facile fabrication of sodium styrene sulfonate-grafted ethylene-vinyl alcohol copolymer as adsorbent for ammonium removal from aqueous solution.

An adsorbent EVOH-g-SSS(H) was successfully synthesized for ammonium removal by one-step grafting SSS onto EVOH particles directly using radiation-induced grafting technique followed by protonation. The effects of adsorbed dose and monomer concentration on grafting yield were investigated. The adsorption behaviors of the EVOH-g-SSS(H) towards ammonium ions (NH4+) were discussed. The adsorption isotherm of NH4+ was a followed Langmuir model with the maximum adsorption capacity of 22.53 mg/g at optimal pH 6.5. For comparison, adsorption kinetics towards NH4+ removal by EVOH-g-SSS(H) and commercially available DIAION PK228 were studied. Both adsorbents were better obeyed pseudo-second-order mode. EVOH-g-SSS(H) for NH4+ uptake was faster than PK228 and reached equilibrium within 5 min. Column experiment showed that the column adsorption capacity of EVOH-g-SSS(H) adsorbent was 9.69 mg/g-ad at SV 10 h-1. The NH4+ concentration in outlet solution can maintain at a very low level even SV was as high as 800 h-1. The elution curve showed the EVOH-g-SSS(H) adsorbent can be regenerated using 1 M HCl. Besides, the removal percentage of NH4+ can be 97% from actual groundwater within 1 min. Such high adsorption efficiency of EVOH-g-SSS(H) makes it to be employed as an adsorbent for NH4+ removal in practical application.