Surface Modifier Research Articles

N, S co-doped hollow carbon nanocages confined Fe, Co bimetallic sites for bifunctional oxygen electrocatalysis

Regulating pore architecture and electronic structure is of significance for improving oxygen electrocatalytic activity of M−N−C catalysts. Herein, N, S co-doped hollow carbon nanocages confined Fe, Co bimetallic sites (FeCo-NS-HNCs) are constructed through an efficient surface bridging strategy. The surface modifier of trithiocyanuric acid trisodium salt bridges Co doped ZIF-8 surface with Fe ions to promote the formation of Fe/Co-Nx sites. The synergistic coupling of metal sites and N, S co-doping manipulates the adsorption/desorption characteristics of M−Nx sites to optimize intrinsic activity. The Kirkendall effect constructs the hollow carbon nanocages, improving the accessibility of M−Nx sites. Benefiting from the ameliorated electronic structure and hollow porous architecture, FeCo-NS-HNCs displays excellent bifunctional oxygen electrocatalytic activity (ΔE = 0.655 V). The liquid and flexible Zn-air batteries of FeCo-NS-HNCs offer prominent power density and cycling stability. This work provides estimable insights into the structure design and activity regulation of M−N−C catalysts for Zn-air battery.

Fabrication and characterization of organically modified layered double hydroxide/poly (lactic acid) nanocomposite by sonication-assisted solution compounding method

The superior physicochemical properties of layered double hydroxides (LDHs) sets them apart from traditional polylactic acid (PLA) fillers. However, achieving efficient dispersion of LDHs within the PLA matrix poses a challenge in the fabrication of PLA/LDHs nanocomposites. In order to enhance the dispersion of LDHs in the PLA matrix and improve their compatibility with PLA, in this study sodium stearate (SS) and sodium dodecyl sulfate (SDS) were used as surface modifiers and intercalation modifiers for LDHs, respectively. Notably, the strategy of intercalation-surface combined modification for LDHs nanofillers in PLA was explored for the first time. Furthermore, the resulting PLA/LDHs nanocomposites were prepared via a sonication-assisted solution compounding method. The results indicate that the addition of LDHs modified through different methods and concentrations affects not only the thermal properties and crystallinity of the PLA/LDHs composites, but also improves the tensile strength and elongation at break of PLA. Notably, the PLA_LDH_SDS_SS_9% composite exhibited an elongation at break that was 230% higher than neat PLA. This study fills a research gap in the field of PLA/LDHs nanocomposites and establishes a significant foundation for the future preparation and application of these.

Reinforcement effect of glass fiber modified by tannic acid and polyethyleneimine on polyamide 6 composites with no volatile organic compounds emission

AbstractAs an important surface modifier, conventional silane coupling agents generally emit volatile organic compounds (VOCs) like methanol or ethanol during the modification of glass fiber. To avoid VOCs emission, a phenol/amine co‐deposition of tannic acid (TA) with polyethyleneimine (PEI) was used to modify glass fiber (TP‐GF) based on mussel‐inspired surface chemistry. The reinforcement effect of TP‐GF on polyamide 6 (PA6) matrix was investigated, and the corresponding results were compared with those of γ‐aminopropyltriethoxysilane (KH550) modified glass fiber (KH550‐GF)/PA6 composites. The results showed that the interfacial adhesion between TP‐GF and PA6 matrix was superior to that between KH550‐GF and PA6 matrix, and thus TP‐GF/PA6 composites manifested more excellent mechanical properties than KH550‐GF/PA6 composites. Among these composites, TP‐GF (1.05 wt% of coating amount)/PA6 composites exhibited the optimal mechanical properties (tensile strength: 151.3 MPa, notched impact strength: 13.8 kJ m−2) compared with KH550‐GF (1.33 wt% of coating amount)/PA6 composites (tensile strength: 144.8 MPa, notched impact strength: 9.5 kJ m−2). In particular, the notched impact strength was significantly increased by 45%. Notably, there was no VOCs generation during the preparation of TP‐GF, indicating that TP‐GF could be used as an environmentally friendly glass fiber for the fabrication of high‐performance PA6 composites.

Recent Advances in Electrochemical Sensors for Sulfur-Containing Antioxidants.

Sulfur-containing antioxidants are an important part of the antioxidant defense systems in living organisms under the frame of a thiol-disulfide equilibrium. Among them, l-cysteine, l-homocysteine, l-methionine, glutathione, and α-lipoic acid are the most typical representatives. Their actions in living systems are briefly discussed. Being electroactive, sulfur-containing antioxidants are interesting analytes to be determined using various types of electrochemical sensors. Attention is paid to the chemically modified electrodes with various nanostructured coverages. The analytical capabilities of electrochemical sensors for sulfur-containing antioxidant quantification are summarized and discussed. The data are summarized and presented on the basis of the electrode surface modifier applied, i.e., carbon nanomaterials, metal and metal oxide nanoparticles (NPs) and nanostructures, organic mediators, polymeric coverage, and mixed modifiers. The combination of various types of nanomaterials provides a wider linear dynamic range, lower limits of detection, and higher selectivity in comparison to bare electrodes and sensors based on the one type of surface modifier. The perspective of the combination of chromatography with electrochemical detection providing the possibility for simultaneous determination of sulfur-containing antioxidants in a complex matrix has also been discussed.

Synthesis of novel bifunctional polyolefins and their application as hydrophobic agents for cotton fabrics

Surface functionalization of cotton fabric was carried out using novel bifunctional polyolefins containing various pendant groups. The hydrophobization of the aforementioned natural material was successfully achieved and the durability of the coatings was proven by SEM-EDS and FT-IR techniques. Water contact angle (WCA) measurements revealed the effect of the functional group type on the properties of the treated surface. The presence of fluoroaryl groups in the polymer chain ensured the highest WCA value. The effect of the type of side groups (aryl vs alkyl, fluorinated vs halogen-free) in the polymer chain on the surface properties was also demonstrated. The modifiers applied did not affect the thermal stability of the treated cotton fabric compared to reference sample. Moreover, the flame-retardant properties of the polyolefin-coated cotton samples were also verified and discussed. This is the first report describing the application of organofunctionalized bifunctional polyolefins as surface modifiers for cotton fabrics.

Strengthened Surface Modification for High-Performance Inorganic Perovskite Solar Cells with 21.3% Efficiency.

Metal halide inorganic perovskites show excellent thermal stability compared to organic-inorganic perovskites. However, the performance of inorganic perovskite solar cells (PSCs) is far from theoretical values, together with unsatisfactory stability, mainly due to the poor interfacial properties. In this work, a facial but effective method is reported to realize high-performance inorganic PSCs by post-modifying the perovskite surface with 2-thiophene ethylamine (TEA). It is found that amine group from TEA can favorably interact with the undercoordinated Pb2+ via Lewis acid-based coordination, while thiophene ring with electron-rich sulfur assists such interaction by functioning as an electron donor. The synergetic interaction allows TEA to passivate perovskite film defects more efficiently, as compared to phenethylamine (PEA) with less electron-donating ability. Moreover, perovskite valence band is slightly upward shift to match with hole transport material and facilitate hole transfer. These combinations result in a reduced non-radiative charge recombination and improved charge carrier lifetime. Consequently, PSCs with TEA modification shows a drastic improvement of VOC by 54mV, yielding a champion PCE of 21.3%, much higher than the control PSCs (19.3%), along with improved ambient stability. This work demonstrates that surface modifier with an electron-rich moiety is critical for achieving efficient and stable inorganic PSCs.

Modification of Hydrophobic Self‐Assembled Monolayers with Nanoparticles for Improved Wettability and Enhanced Carrier Lifetimes Over Large Areas in Perovskite Solar Cells

The development of perovskite solar cells (PSCs) with low recombination losses at low processing temperatures is an area of growing research interest as it enables compatibility with roll‐to‐roll processing on flexible substrates as well as with tandem solar cells. The inverted or p–i–n device architecture has emerged as the most promising PSC configuration due to the possibility of using low‐temperature processable organic hole‐transport layers and more recently, self‐assembled monolayers such as [4‐(3,6‐dimethyl‐9H‐carbazol‐9‐yl)butyl]phosphonic acid (Me‐4PACz). However, devices incorporating these interlayers suffer from poor wettability of the precursor leading to pin hole formation and poor device yield. Herein, the use of alumina nanoparticles (Al2O3 nanoparticles (NPs)) for pinning the perovskite precursor on Me‐4PACz is demonstrated, thereby improving the device yield. While similar wettability enhancements can also be achieved by using poly[(9,9‐bis(3′‐((N,N‐dimethyl)‐N‐ethylammonium)‐propyl)‐2,7‐fluorene)‐alt‐2,7‐(9,9‐dioctylfluorene)]dibromide (PFN‐Br), a widely employed surface modifier, the incorporation of Al2O3 NPs results in significantly enhanced Shockley–Read–Hall recombination lifetimes exceeding 3 μs, which is higher than those on films coated directly on Me‐4PACz and on PFN‐Br‐modified Me‐4PACz. This translates to a champion power conversion efficiency of 19.9% for PSCs fabricated on Me‐4PACz modified with Al2O3, which is a ≈20% improvement compared to the champion device fabricated on PFN‐Br‐modified Me‐4PACz.

Synthesis of new dithiocarbamate and xanthate complexes and their application in enrichment processes

Ore flotation is the main and defining technological process in ore benefication and non-ferrous metals production. The flotation process requires the use of a variety of chemical reagents, including collectors, frothers, surface modifiers, and pH regulators. The development and selection of suitable reagents for the processed material play a vital role in efficient flotation. The flotation activity of collectors depends fundamentally on the composition and structure of the hydrophobic and hydrophilic fragments forming the flotation agent molecule, as well as on the nature of the ore that undergoes flotation processing. In this regard, the identification and study of the “substance structure–flotation activity” relation, as well as the search for new effective flotation reagents gain importance within applied organic and organoelement chemistry and related branches of science and technology. In this article, we review syntheses of effective collector reagents, namely xanthates and dithiocarbamates, based on the literature data for the past five years. Where necessary, earlier sources are provided. The reaction conditions and yields of the target compounds are presented using schemes. In addition, we present the results of flotation tests on the surfaces of various ores and the data on the mechanism of concentrate extraction. According to the reviewed publications, the fixation of collector reagents on the surface of minerals can be regarded as a complexation process of the collector functional groups and metal ions located on the surface of the mineral.

Daytime radiative cooling aerogel with favorable amphiphobic surface properties

Passive daytime radiative cooling technology without any electricity input offers great promise to mitigate carbon emissions and greenhouse effects. As a type of daytime radiative cooling emitters (DRCEs), daytime radiative cooling aerogel attracts a lot of attention and has great advantages in minimizing parasitic solar absorption and reducing environmental heat gain. However, designing daytime radiative cooling aerogel with amphiphobic surface properties is still challenging. Herein, a novel daytime radiative cooling aerogel based on eco-friendly bacterial cellulose (BC) as the skeleton, modified barium sulfate (BaSO4) as functional particles and fluoride coating as amphiphobic surface modifier was developed by simple freeze-drying and spraying. The optimal daytime radiative cooling aerogel, designated as M-BC/BaSO4-14 (M-BC/BaSO4-14 refers to the modified BC/BaSO4 aerogel), exhibited a high average reflectivity (95.6%) and excellent average emissivity (98.1%). The M-BC/BaSO4-14 achieved a mean temperature drop of 6.64°C and maximum temperature drop of 13.30°C on a cloudy day, and a mean temperature drop of 8.49°C and maximum temperature drop of 12.34°C on a clear day. It should be noted that the temperature drop referred to the temperature inside the measurement box (called the inner ambient temperature throughout this article) not the true ambient temperature. Meanwhile, the M-BC/BaSO4-14 aerogel exhibited favorable amphiphobic surface properties (water contact angle of about 151°, ethylene glycol contact angle of 141° and N-Hexadecane contact angle of 139°) and daytime radiative cooling performance before and after self-cleaning changed insignificantly. This work provides a viable strategy for the simultaneous improvement of the spectral properties and amphiphobic surface properties of the DRCEs.

Preparation of pH/Light dual-responsive biocompatible polymer micelles: Application to curcumin delivery

Polymer micelles play an important role in the research of drug delivery system because of their nano-size, unique “core-shell” structure and surface modifiability. A pH/photosensitive drug carrier, PEG-PDMAEMA-PNBAE, was synthesized by atom transfer radical polymerization (ATRP) using hydrophilic poly (N, N dimethylaminoethyl methacrylate) (PDMAEMA) as the pH-responsive chain segment and hydrophobic poly (o-nitrobenzyl acrylate) (PNBAE) as the light-responsive chain segment. The molecular and structural characteristics of the polymer were spectroscopically characterized with Fourier transform infrared spectrometer (FT-IR), Nuclear magnetic resonance hydrogen spectrum (1H NMR) and Gel permeation chromatography column (GPC). The morphology and size of micelles were observed by Scanning electron microscope (SEM) and Transmission electron microscope (TEM). The stability of micelles was detected by Laser particle size analyzer (DLS). The Critical micelle concentration (CMC) of the polymer was analyzed by Fluorescence spectrophotometer (Flu), and the photosensitivity of the micelles was determined by Ultraviolet–visible spectrophotometer (UV). The results showed that the synthesized polymers could self-assemble into homogeneous and stable spherical micelles and their particle size was about 100 nm with effective light sensitivity. Curcumin (Cur) was used as a model drug to investigate the adsorption and release abilities of the micelles. The adsorption performance test of the polymeric micelles showed an encapsulation rate of 77.82% and a drug loading capacity of 13.46%. In vitro drug release results showed cumulative drug release rates of 31.79% and 46.55% at pH 5.5 and pH 5.5+UV, indicating the dual pH and light responsiveness of the synthesized carrier. The in vitro hemolysis and cytotoxicity test demonstrated that the carrier has good biosafety.

Systematically Designed Surface and Morphology of Magnetite Nanoparticles Using Monocarboxylic Acid with Various Chain Lengths under Hydrothermal Condition.

Hydrothermal synthesis of surface-modified magnetite nanoparticles (NPs) was performed in a batch reactor at 200 °C for 20 min while using monocarboxylic acid with various alkyl chain lengths (C6 to C18) as surface modifiers. The short-chain cases (C6 to C12) successfully gave the surface-modified NPs with uniform shape and magnetite structure, while the long-chain cases (C14 to C18) gave the NPs with nonuniform shape and two structures (magnetite and hematite). Additionally, the synthesized NPs were revealed to have single crystallinity, high stability, and ferromagnetic property, which were useful for hyperthermia therapy via various characterization techniques. These investigations would guide the selection guidelines for a surface modifier to control the structure, surface, and magnetic properties of surface-modified magnetite NPs with high crystallinity and stability, particularly for hyperthermia therapy applications.

Al2O3 nanoparticles as surface modifier enables deposition of high quality perovskite films for ultra-flexible photovoltaics

Advanced photovoltaics, such as ultra-flexible perovskite solar cells (UF-PSCs), which are known for their lightweight design and high power-to-mass ratio, have been a long-standing goal that we, as humans, have continuously pursued. Unlike normal PSCs fabricated on rigid substrates, producing high-efficiency UF-PSCs remains a challenge due to the difficulty in achieving full coverage and minimizing defects of metal halide perovskite (MHP) films. In this study, we utilized Al2O3 nanoparticles (NPs) as an inorganic surface modifier to enhance the wettability and reduce the roughness of poly-bis(4-phenyl) (2,4,6-trimethylphenyl) amine simultaneously. This approach proves essentials in fabricating UF-PSCs, enabling the deposition of uniform and dense MHP films with full coverage and fewer defects. We systematically investigated the effect of Al2O3 NPs on film formation, combining simulation with experiments. Our strategy not only significantly increases the power conversion efficiency (PCE) from 11.96% to 16.33%, but also promotes reproducibility by effectively addressing the short circuit issue commonly encountered in UF-PSCs. Additionally, our UF-PSCs demonstrates good mechanical stability, maintaining 98.6% and 79.0% of their initial PCEs after 10,000 bending cycles with radii of 1.0 and 0.5 ​mm, respectively.

Preparation of large-size alumina ceramic parts by DLP 3D printing using high-solid-loading paste and optimizing the debinding process

Digital light processing (DLP) is a promising additive manufacturing method for creating complex structural alumina ceramic with high precision, high efficiency, and low cost. However, printing large-size parts with high feature resolution by DLP, obtaining high-performance pastes, and optimizing the debinding process are challenges that still need to be overcome. In this study, an advanced top-down Matrix-DLP technology that seamlessly connects two high-definition-resolution DLP projectors, with high resolution and a large projection area, was used to achieve fine-structured large-size alumina green bodies. The homogeneous and stable non-self-levelling alumina pastes suitable for the DLP technology were developed, with a high solid loading up to 55 vol%, viscosity of 35.0 Pa s at 30 s−1, and good rheological properties by innovatively using 2.5 wt% P5318 as surface modifiers of alumina powders and with only a 0.244% volume of bubble residue by using 0.5 wt% BYK-066N defoamer in combination with a vacuum planetary stirring defoaming process. The debinding processes were designed based on TG-DSC analysis and then optimized, and it was proved that the segmented-atmosphere debinding process was the best approach and can obtain defect- and carbon residue-free bodies with uniform grain distribution, and can also achieve non-destructive debinding for the thick-walled parts with thickness greater than 10 mm. The effects of the debinding residual carbon and the solid loading on the microstructure and properties after sintering were also investigated. Consequently, the high-precision large-size alumina ceramic with good interlayer bonding, dense microstructure, and high microhardness of 17.92 GPa was obtained.

Optimizing the size distribution of zinc borosilicate glass powder by organic solvent and tetradecylphosphonic based wet milling

Zinc borosilicate glass are crucial adhesive medium in modern electronic industry. However, it is still hard to prepare the zinc borosilicate glass with uniform particle size distribution. Herein, narrow particle size distribution and reduced hemispherical point temperature of zinc borosilicate glass was obtained by choosing low polarity, viscosity and surface tension organic solvent as well as surface modifier in the wet ball milling method. It is found that xylene, ethanol and isopropyl alcohol are good liquid medium for wet ball milling. Moreover, tetradecylphosphonic acid (TDPA) as a surface modifier could effectively reduce the formation of surface hydroxyl group in glass powder by the nucleophilic substitution reaction of the phosphonic acid group, showing superb anti-aggregation properties. Therefore, this work provides a general method for controlling particle size distribution of glass powder.

Degradation of methylene blue using Methyltrimethoxysilane doped ZnO nanoparticles and inactivation of gram (+ve) and (-ve) bacteria

Non-biodegradable effluents form dying industries cause harm to environment. Usage of nanomaterials is an effective method for purification of such effluents. Agglomeration of photoactive nanomaterials can be reduced by doping with suitable coupling agents. The present study explores usage of Polyethylene glycol 4000 and Methyltrimethoxysilane as surface modifiers to Zinc oxide by sol–gel method. Structural analysis revealed hexagonal wurtzite phase of synthesized ZnO nanomaterial. Diffraction peaks had no major shift in position denoting crystallinity and purity. Presence of nano-sized particles was confirmed by FESEM analysis. Investigation of optical band bap energy of ZnO, ZnO/PEG-4000 and ZnO/PEG-4000/MTMS was made. Antibacterial efficacy analysis showed, all combinations of ZnO were sensitive against Staphylococcus aureus, Bacillus cereus, Escherichia coli and Pseudomonas aeruginosa. Photocatalytic degradation analysis revealed ZnO functionalized by both polymer and silane exhibited highest degradation efficiency under visible light source for MB dye, the efficiency was maintained even after five cyclic degradations.

Corrosion inhibition performance of developed epoxy coatings containing carbon nanocapsules loaded with diethylenetriamine

In recent years, hollow structured nanomaterials owe high attention to research, especially when applied to organic coatings due to their high surface area, loading capacity, and flexible shape and structure. Towards this direction, mesoporous hollow carbon nanospheres (MPHS) have been synthesized using the self-assembly method with an average diameter of 280 nm using silica particles as a hard template. The etching of the silica cores was carried out using alkaline etching with NaOH which effectively removed the cores as confirmed by the EDX and FTIR. The MPHS has BET surface area, pore volume, and pore radius of 830.8 m2/g, 1.1 cc/g, and 3.4 nm respectively which support the loading of diethylenetriamine (DETA). The DETA acts as a corrosion inhibitor, surface modifier, and hardener loaded into MPHS with a high loading rate (44 %) to develop MPHS@ DETA. 3 wt% of the MPHS@ DETA was blended with an epoxy coating (MPHS@ DETA-EP) as an anti-corrosion pigment and then the properties of the developed epoxy coatings were systematically characterized. The developed MPHS@ DETA-EP shows excellent anti-corrosion behavior after continuous exposure to corrosive media for 40 days making the coating suitable for several industrial applications.

The characteristics and resource utilization of chromium-containing electroplating sludge.

Chromium (Cr)-containing electroplating sludge is a hazardous solid waste and has a detrimental effect on human health and the environment. The existing mainstream methods still have problems such as high costs and complicated processes. In this study, the composition, phase composition, heavy metal content, microstructure, calcination characteristics, and vitrification of chromium electroplating sludge were analyzed by XRF, XRD, ICP-OES, and SEM. The results showed that calcination of sludge at 650°C and 850°C produces magnetic ferrite ZnFe2O4. When solidifying sludge with D245 glass, the maximum sludge addition is 35% in order to make the Cr(VI) leaching concentration meet the national standard. Here, the plastic solidification method was developed to solidify Cr-containing electroplating sludge and fill plastic building templates. This method is simple to operate, low cost, and a promising prospect. The effect of surface modification of electroplating sludge was discussed. The most obvious effect of the modification is sodium stearate, modified by sodium stearate powder oil absorption decreases value from 0.62g/1.0g to 0.40g/1.0g. When sodium stearate with 1.5% was used as the sludge surface modifier, the contact angle reached 88.98°. Then, the effect of the ratio of PVC to modification sludge on the performance of PVC building templates was investigated and compared with that of the templates prepared by calcium carbonate filling. It was found that the performance of the sludge-filled PVC template was superior to the traditional calcium-carbonate filled PVC template when the ratio of PVC to sludge is 100:150, and the tensile strength reached 15.3233 Mpa and 13.745 Mpa, respectively. Thus, this study demonstrates a new method to treat and recycle Cr-containing electroplating sludge.

Schottky barrier height engineering on MoS2 field-effect transistors using a polymer surface modifier on a contact electrode

Two-dimensional (2D) materials are highly sought after for their superior semiconducting properties, making them promising candidates for next-generation electronic and optoelectronic devices. Transition-metal dichalcogenides (TMDCs), such as molybdenum disulfide (MoS2) and tungsten diselenide (WSe2), are promising alternative 2D materials. However, the devices based on these materials experience performance deterioration due to the formation of a Schottky barrier between metal contacts and semiconducting TMDCs. Here, we performed experiments to reduce the Schottky barrier height of MoS2 field-effect transistors (FETs) by lowering the work function (Фm = Evacuum − EF,metal) of the contact metal. We chose polyethylenimine (PEI), a polymer containing simple aliphatic amine groups (–NH2), as a surface modifier of the Au (ФAu = 5.10 eV) contact metal. PEI is a well-known surface modifier that lowers the work function of various conductors such as metals and conducting polymers. Such surface modifiers have thus far been utilized in organic-based devices, including organic light-emitting diodes, organic solar cells, and organic thin-film transistors. In this study, we used the simple PEI coating to tune the work function of the contact electrodes of MoS2 FETs. The proposed method is rapid, easy to implement under ambient conditions, and effectively reduces the Schottky barrier height. We expect this simple and effective method to be widely used in large-area electronics and optoelectronics due to its numerous advantages.

One-step cross-linking of amino-rich chitosan aerogels for efficient and selective adsorption of uranium from radioactive nuclear wastewater

Extraction of uranium from radioactive wastewater is a critical challenge in the modern era of the prevalence of nuclear fuel. Herein, polyethyene polyamine/polydopamine modified carboxylated chitosan aerogels (PEPAx/PDAy-CMCSm-n) were obtained by a simple one-step cross-linking method for efficient and selective uranium adsorption. Carboxylation of chitosan substrates greatly improved solubility in water, which increased flexibility for biomass chitosan modification. More importantly, the PDA bonded coating avoided the problem of low availability of reactive sites caused by steric hindrance between CMCS and PEPA. The abundant –NH2 in the surface modifier PEPA endowed the chitosan aerogels with sufficient active sites, making it exhibit a high uranium adsorption capacity of 467.73 mg g−1. The optimal preparation scheme of aerogels was designed by comprehensive orthogonal experiments for the reactive monomer additive amounts. The obtained PEPA2.0/PDA0.7-CMCS3.5–250 showed prominent kinetics, excellent selectivity and superior regeneration performance. Importantly, reducing uranium concentration from 12.35 mg L-1 to 10 ug L-1 in simulated nuclear wastewater, which is below the Ministry of Environmental Protection of the People’s Republic of China uranium limit for drinking water (30 ug L-1). Besides, the density functional theory calculations revealed the binding mechanism and coordination mode between the adsorption unit and UO22+. Such efficient and low-cost adsorbed aerogels are extremely advantageous for uranium capture in real environments.

EFFECTS OF POROUS g-C3N4 NANOSHEETS AND STEARIC ACID ON THE DURABILITY OF WATERBORNE ACRYLIC RESIN COATING

Durability is a key factor to determine the service life of organic coating. The addition of nanomaterials can improve the mechanical properties and compactness of the organic coatings. As a kind of nanomaterial, g-C3N4 has lamellar structure and can be excited by visible light. At the same time, its cost is low. So it can be selected as a filler to prepare organic coating. The lamellar structure of g-C3N4 is favorable for its dispersion in organic coatings. Stearic acid is an environmentally friendly material with low surface energy. It can improve the hydrophobicity of the coating. In this research, porous g-C3N4 nanosheets were used as filler and stearic acid was used as surface modifier to prepare waterborne acrylic resin-based organic composite coating. The chemical reagent durability, electrochemical durability and mechanical properties of the composite coating were tested. At the same time, the photocatalytic degradation performance of the coating surface was also tested. The results showed that g-C3N4 as filler and stearic acid could effectively improve the durability of the waterborne acrylic resin coating. Meanwhile, the coating surface has obvious visible light-activated photocatalytic performance due to the addition of g-C3N4.