Surface Groups Research Articles

Rapid preparation of N,P co-doped carbon for advanced oxidative degradation of wastewater

Heteroatom-doped porous carbon materials are highly favored as catalysts for activating persulfates in the oxidative degradation of organic pollutants due to their low metal leaching risk and cost-effectiveness. Nonetheless, the complex process of creating heteroatom-doped carbon materials often results in suboptimal doping effects. This study uses N,P-enriched plants (Eichhornia crassipes after being used for nutrient-rich water remediation) as a raw material to prepare N-P co-doped catalysts in a single step. We thoroughly investigated their performance and mechanisms in dye degradation. The findings demonstrated that the adsorbent, with its rich pore structures, surface chemical functional groups, and graphite defect structures, could completely degrade a 100 mg L−1 MB solution within 20 min. Free radical quenching experiments and EPR analysis confirmed the presence of •OH, SO4•—, O2•— and 1O2, verifying their oxidative contributions. Moreover, it was determined that the non-radical pathway (1O2 oxidation) primarily drives the oxidative degradation in this system. Additionally, tests using a small-scale fixed-bed reactor and interference resistance highlighted the practical application potential of the adsorbent developed in this study. This study not only offers a dual solution for tackling nutrient enrichment and organic pollution in water bodies but also introduces a straightforward method for preparing N, P co-doped catalysts, significantly benefiting environmental protection.

Enhancing the degradation of microplastics through combined KMnO4 oxidation and UV radiation

The pervasive issue of microplastics in aquatic environments presents a formidable challenge to traditional water treatment methodologies, including those utilizing KMnO4. This study pioneers advanced oxidation processes (AOPs) method aimed at improving the degradation of PE microplastics by employing a dual treatment strategy that combines KMnO4 oxidation with UV irradiation. Detailed analysis of the surface modifications and chemical functional groups of the treated PE microplastics revealed the establishment of Mn-O-Mn linkages on their surfaces. Weight reductions of 3.9%, 4.9%, and 7.5% were observed for the KMnO4/UVA, KMnO4/UVB, and KMnO4/UVC treatments over seven days, respectively. The emergence of carboxyl and hydroxyl groups played a crucial role in accelerating the degradation process. Notably, the combined application of UVC rays and KMnO4 resulted in the most effective degradation of PE microplastics observed in our study. The process significantly enhanced the formation of MnO2 particles from KMnO4 oxidation, with concentrations ranging from 0.036 to 0.070 mM for KMnO4/UVA, 0.066–0.097 mM for KMnO4/UVB, and 0.086–0.180 mM for KMnO4/UVC. Furthermore, the influence of varying pH levels, KMnO4 concentrations, and different water sources on the degradation efficacy was investigated. The pivotal role of free radicals and reactive manganese species in promoting the degradation of PE microplastics was identified. A comparative evaluation with treatments solely utilizing KMnO4 or UV light highlighted the enhanced effectiveness of the combined approach, demonstrating its potential as an efficient solution for reducing microplastic contamination in aquatic systems.

A computational study of adsorption on activated carbons containing basic oxygenated surface groups of two priority organochlorine pesticides from water

In previous work, molecular modeling was used to investigate how acidic and nitrogen-containing surface groups (SG) on an activated carbon (AC) model affect the adsorption of chlordecone (CLD) and β-hexachlorocyclohexane (β-HCH), considering the effects of pH and hydration. Interactions involving acidic SGs at neutral pH indicated chemisorption, while interactions with nitrogen basic SGs suggested physisorption. This study presents a theoretical investigation of the interactions between these pesticides and oxygenated SGs on AC. A coronene molecule with functional groups—specifically pyrone, chromene, or ketone at the edges was used as a simplified model of AC. The Multiple Minima Hypersurface methodology was employed to study the interactions between CLD and β-HCH with SGs on AC using the PM7 semi-empirical Hamiltonian. Further re-optimization of the obtained structures for pesticide-AC complexes was performed using Density Functional Theory. The Quantum Theory of Atoms in Molecules was applied to characterize the interaction types using the Nakanishi criteria. No interactions were observed at acidic pH for both pollutants, whereas dispersive interactions were found at neutral and basic pH, indicating a physisorption process. Molecular dynamics simulations were also conducted to illustrate these findings. Ultimately, our previous studies showed that the adsorption process of CLD and β-HCH on AC is more effectively enhanced with acidic SGs rather than basic SGs. Moreover, MD simulations of β-HCH and CLD pesticides at concentrations higher than their solubilities reveal aggregation in both pure aqueous solutions and those containing AC. Analysis of MD trajectories and RDFs shows that hydrophobic interactions lead to aggregation of these molecules. RDFs indicate that β-HCH aggregates more in the solution due to its lower solubility compared to CLD. This aggregation reduces pesticide adsorption on AC surfaces, with β-HCH showing a more significant decrease in adsorption, dropping by more than half. Similar effects were observed with other biochar models for both pesticides.

Construction of electrochemical immunosensor from MXene/multi-walled carbon nanotubes/gold nanoparticles for specific detection of carcinoembryonic antigen.

With the advancement of nanotechnology, various types of nanomaterials have been integrated into electrochemical immunoelectrodes to enhance their performance. Among these, MXene stands out as a promising candidate due to its high electron transfer capacity and abundant surface chemical groups. However, the improvement in electrode performance is often hindered by the self-restacking and agglomeration of MXene. To address this issue, multi-walled carbon nanotubes (MWCNTs) were selected to form composites with MXene. Subsequently, a label-free immunosensor, BSA/Ab/AuNPs/MXene-MWCNTs-Nafion/ITO, was fabricated for specific detection of carcinoembryonic antigen (CEA), a widely used tumor marker. The results demonstrated that the incorporation of MWCNTs can effectively prevent the self-stacking of MXene. Moreover, the composites enhanced the loading of gold nanoparticles (AuNPs) to connect the antibodies, thereby improving electronic transmission signals and sensitivity. The sensor exhibited excellent analytical performance towards CEA with a wide linear range (0.050 to 200ngmL-1) and a low limit of detection of 0.015ngmL-1 (S/N = 3). The possibility of it being applied in clinical trials was verified by using ELISA and differential pulse voltammetry (DPV) assays to detect CEA in serum samples. The recoveries ranged from 95.34 to 102.09% with relative standard deviations (RSDs) below 5.00%. Furthermore, the sensor displayed satisfactory selectivity, repeatability, and stability. We hope the findings highlight promising prospects for advanced immunosensor development and alternative strategies in cancer diagnosis.

Comparative Evaluation of Biofilm Formation on Temporization Crown Materials Used in the Rehabilitation of Primary Dentition With Different Polishing Materials: An In Vitro Study.

Introduction Advancements in dental materials have enhanced aesthetic treatments for managing dental caries and injuries in primary dentition. Bis-acryl composite-based temporization materials are now preferred for restoring primary crowns due to their superior properties. However, prolonged exposure to dietary and hygienic factors can lead to discoloration and roughness, making efficient polishing essential to prevent plaque buildup. Objective This study aims to evaluate Streptococcus mutans biofilm formation on temporization material polished with different polishing systems. Methods This study tested bis-acryl methacrylate temporization material. Thirty disk-shaped specimens were prepared and divided into three groups according to the polishing system used (n = 10 per group): Shofu Super Snap mini kit (Shofu, San Marcos, CA), aluminum oxide polishing paste, and propol polishing paste. Each group's specimens were polished according to the manufacturer's instructions. Surface roughness (SR), scanning electron microscopy (SEM) morphological analysis, and Streptococcus mutans biofilm formation were assessed for each group. Results The results showed significant differences in roughness average (Ra) values among the polishing materials, with the Shofu Super Snap mini kit having the highest roughness (Ra = 2.04), followed by propol polishing paste (Ra = 1.30)and aluminum oxide paste (Ra = 0.75). Additionally, polishing methods significantly affected mean colony-forming unit (CFU) levels, with the first group having the highest mean CFU value (0.24), with SEM images showing substantial biofilm formation by Streptococcus mutans. Conclusion Bacterial biofilm formation on the aluminum oxide paste group's surface differed from that on the propol polishing paste and aluminum oxide disc groups. The polishing techniques that we tested significantly influenced surface properties and biofilm formation. These findings suggest that selecting an appropriate polishing system can reduce the risk of gingival inflammation associated with temporization materials.

Comparative analysis of EBT dye removal using Spartium junceum and derived activated carbon: experimental and DFT insights

ABSTRACT This study explores the use of Spartium junceum biomass (SJ) to create activated carbon (SJAC) through a one-step activation with phosphoric acid. Characterisation of SJ and SJAC was conducted using FTIR spectroscopy, pHpzc measurement, nitrogen adsorption/desorption isotherms, and SEM to analyse their surface chemical groups, morphology, and texture. Results showed that SJAC has a well-developed mesoporous structure, high pore volume, and a significantly enhanced specific surface area (325.759 m2 g−1) compared to raw SJ (1.647 m2 g−1). The adsorptive performance of SJ and SJAC was tested by removing the anionic dye Eriochrome Black T (EBT). Using central composite design under response surface methodology, batch experiments were optimised for factors like pH, adsorbent dosage, initial EBT concentration, and contact time. Optimal conditions were determined using a desirability function. Adsorption data were analysed with various isothermal models, showing that the Freundlich model best described SJ, while the Langmuir model was more suitable for SJAC. SJAC exhibited an exceptional adsorption capacity of 261.36 mg g−1, about five times higher than SJ. Thermodynamic analysis indicated that the adsorption process for both sorbents was spontaneous and endothermic. Density functional theory was used to investigate the adsorption mechanism of EBT on SJ and SJAC, identifying multiple mechanisms such as electrostatic interactions, pore filling, hydrogen bonding, and π-π stacking, with pore filling being the primary mechanism for SJAC. SJAC maintained over 77% EBT adsorption efficiency across four reuse cycles, highlighting its potential for EBT remediation applications.

Preparation of bacterial cellulose/acrylic acid-based pH-responsive smart dressings by graft copolymerization method

Conventional wound dressings used in trauma treatment have a single function and insufficient adaptability to the wound environment, making it difficult to meet the complex demands of the healing process. Stimuli-responsive hydrogels can respond specifically to the particular environment of the wound area and realize on-demand responsive release by loading active substances, which can effectively promote wound healing. In this paper, BC/PAA-pH responsive hydrogels (BPPRHs) were prepared by graft copolymerization of acrylic acid (AA) to the end of the molecular chain of bacterial cellulose (BC) network structure. Antibacterial pH-responsive ‘smart’ dressings were prepared by loading curcumin (Cur) onto the hydrogels. Surface morphology, chemical groups, crystallinity, rheological, and mechanical properties of BPPRHs were analyzed by different characterization methods. The drug release behavior under different physiological conditions and bacteriostatic properties of BPPRH-Cur dressings were also investigated. The results of structural characterization and performance studies show that the hydrogel has a three-dimensional mesh structure and can respond to wound pH in a ‘smart’ drug release capacity. The drug release behavior of the BPPRH-Cur dressings under different environmental conditions conformed to the logistic and Weibull kinetic models. BPPRH-Cur displayed good antimicrobial activity against common pathogens of wound infections such as E. coli, S. aureus, and P. aeruginosa by destroying the cell membrane and lysing the bacterial cells. This study lays the foundation for the development of new pharmaceutical dressings with positive health, economic and social benefits.

Creation, Control, and Modeling of NV Centers in Nanodiamonds

AbstractSensing based on Nitrogen‐Vacancy (NV) centers in nanodiamonds (NDs) represents a potentially groundbreaking technology with broad applications. Nevertheless, the optimization of their quantum‐optical properties is still a challenging issue. The present work aims at enhancing and controlling NV centers optical properties in NDs by combining their surface chemistry tuning and proton beam irradiation. Systematic thermal oxidations are carried out to study the evolution of surface chemical groups (IR spectroscopy), as well as their influence on optical properties (photoluminescence spectroscopy, PL decay measurements). Proton irradiation is performed by exploring a wide range of fluences (1014 – 1017 cm−2) in order to precisely control the amount of NV centers, thus defining the conditions that maximize their creation and emission intensity. In addition, NV centers charge state control is achieved by assessing NV−/NV0 ratio upon different surface termination tuning and NV centers amount. Finally, a novel predictive mathematical model is developed, allowing for the evaluation of the efficiencies of the formation of both NV− and NV0. Although the model is tested in the specific case study with proton irradiated NDs, it offers a broad applicability, thus representing a key landmark in the prediction of the outcome of ion‐beam‐based color centers generation in diamond.

Fabrication of melamine formaldehyde/graphene oxide composite for efficient static and dynamic adsorption of lead ions from aqueous medium.

The present work discusses the synthesis, characterization, and environmental applications of graphene oxide (GO), melamine formaldehyde resin (MF), and melamine formaldehyde/graphene oxide composite (MGO) for the efficient removal of Pb2+ from aqueous medium via batch and column procedures. TGA, XRD, TEM, zeta potential, nitrogen adsorption/desorption, ATR-FTIR, and other characterization techniques revealed that MGO is characterized by a greater surface area (609 m2/g), total pore volume (1.0106 cm3/g), pHPZC (6.5), and the presence of various surface chemical functional groups. The synthesized solid adsorbents were used in both static and dynamic adsorption processes to remove Pb2+, with varying application parameters such as pH, starting concentration, adsorbent dosage, and shaking time in the case of static adsorption method. While through the column adsorption process the effects of column bed height, flow rate, and starting Pb2+ were taken into consideration. Results of the batch adsorption demonstrated that MGO had the highest Langmuir adsorption capacity (201.5 mg/g), and the adsorption fit the nonlinear Langmuir adsorption model and Elovich kinetic models. The adsorption of Pb2+ onto all prepared solid materials is endothermic, spontaneous, and physical in nature, as demonstrated by thermodynamic studies. Column adsorption of Pb2+ well fitted by Thomas and Yoon Nelson nonlinear adsorption models. MGO showed a maximum column adsorption capacity of 168 mg/g when applying 4 cm, 15 mL/min, and 150 mg/L as bed height, flow rate, and initial Pb2+, respectively. With only a 12.6% reduction in its adsorption capacity, column regeneration showed that MGO exhibited a high degree of reusability even after five cycles of adsorption/desorption studies.

Effect of metal doping on the microwave absorption performance of multi-element (metal, N, and Cl) doped carbon composites

Multi-element-doped carbons are actively being pursued as efficient lightweight microwave absorbers. In this work, metal, nitrogen and chlorine codoped carbons (metal,N,Cl–C, where metals = Ni, Co, Mn, or Zn) were synthesized through the high-temperature carbonization of polypyrrole doped with hydrochloric acid (PPy-HCl) and prepared in the presence of certain metal chloride salts (NiCl2, CoCl2, MnCl2, or ZnCl2). The dielectric parameters and microwave absorption properties of the metal,N,Cl–C composites could be regulated by simply altering the type of metal salt. Compared with N,Cl–C, it was discovered that Co,N,Cl–C and Ni,N,Cl–C possessed higher graphitization degrees, smaller particle sizes and more surface chemical functional groups (metal−N), which significantly improved the conduction loss and polarization loss effects including interfacial polarization and dipole polarization. At a filler ratio of 9.0 wt%, Ni,N,Cl–C displayed a wide effective absorption bandwidth (EAB, RL ≤ −10 dB) of 7.1 GHz at a thickness of 2.5 mm and a minimum reflection loss (RLmin) of −29.7 dB at 9.7 GHz and 3.5 mm thickness. Similarly, Co,N,Cl–C offered an RLmin value of −48.2 dB at 11.3 GHz and a thickness of 3.0 mm and an EAB of 6.0 GHz at a thickness of 2.5 mm. These results showcase the advantages of metal,N,Cl–C composites as microwave absorbers.

The effect of flame treatment on the compressive strength of composite sandwich panels made of pure epoxy resin H‐shaped structures and hollow glass bead/epoxy resin composite material

AbstractAt present, syntactic foam composites (HGB/EP) made of epoxy resin (EP) and hollow glass beads (HGBs) have received extensive attention in the research field of lightweight materials because of their high compression strength‐to‐density ratio. However, the deep‐sea environment has put forward higher requirements for the compressive properties of materials. The traditional sandwich structure with HGB/EP as the core has gradually failed to meet the requirements for the mechanical properties of equipment deeper in the ocean. This paper proposes a sandwich structure comprising a pure EP H‐shaped structural component as the rigid skeleton and an HGB/EP syntactic foam composite as the lightweight filling component. The pure EP H‐shaped structural component was subjected to flame treatment using a butane flame jet at different distances. The compression resistance of the resulting sandwich structure was tested, and the results showed varying degrees of improvement in compressive strength after flame treatment. The effects of flame treatment on the surface adhesion performance of the pure EP were characterized using compression‐shear tests, optical microscopy, contact angle tests, infrared spectroscopy, and flame temperature tests. The results demonstrated that flame treatment at a distance of 0 cm significantly increased the oxygen‐containing functional groups on the surface of the pure EP, improved the wettability of the pure EP surface, increased the adhesive strength between the pure EP H‐shaped structural component and HGB/EP, and enhanced the compressive strength of the sandwich structure. The shear strength of the shear test specimens improved by 33.0%, while the compressive strength of the sandwich structure specimens increased by 17.5%.Highlights The sandwich structure composed of pure epoxy resin H‐shaped structure and foam composite material was prepared. The distance of flame treatment affects the surface chemical groups of epoxy resin. Flame treatment significantly improved the surface wettability of epoxy resin.

Designing activated carbon and porous carbon nanofibers for insight into their differences in adsorption affinity mechanisms of VOCs

The adsorption technology has been considered as an effective and economical strategy to control volatile organic compounds (VOCs) through various types of porous materials. As two potential porous materials, activated carbon and carbon nanofibers were synthesized as VOCs adsorbents. In order to investigate the difference in the adsorption of VOCs between activated carbon and carbon nanofibers, the specific surface area, pore structure and chemical functional groups of VOCs adsorbent were analyzed. In particular, the carbon nanofibers (CNF) activated at 800 ℃ showed an excellent specific surface area (2524 m2·g−1), abundant pores (1.66 mL·g−1), and rich functional groups (N: 8.29 at%). Meanwhile, the carbon nanofibers had a better adsorption performance for acetone (1069.82 mg·g−1) and toluene (427.72 mg·g−1) than activated carbon materials. Furthermore, the theoretical calculations were conducted to reveal the mechanism of favorable adsorption on the CNFs. The theoretical adsorption energies of CNF are −31.9 kJ·mol−1 (acetone) and −67.5 kJ·mol−1 (toluene), respectively, which have more favorable adsorption sites and stronger charge redistribution than activated carbon. This research guided the approach to obtain the porous carbon nanofibers and provided the evidence for CNFs (curved carbon) exhibiting a better adsorption ability to VOCs.

Antihyperlipidemic and antioxidant effects of biogenic copper oxide nanoparticles in diabetic rats

Diabetes mellitus is often associated with metabolic disorders like hyperglycemia, hyperlipidemia, oxidative stress and obesity. Health problems related to these disorders are on a rise globally. Although nanotechnology based approaches have been explored for diabetes treatment, specific information on alleviation of the associated health problem is scanty. Here we report the beneficial effects of copper oxide nanoparticles (CuOnpls) for the control of hyperlipidemia and oxidative stress caused due to diabetes. Wistar rats were fasted overnight and type 2 diabetes was induced by intraperitoneal (i.p.) injection of freshly prepared nicotinamide followed by streptozotocin. Induction of diabetes was confirmed by estimation of blood glucose levels of the animals. Estimation of total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL) and high density lipoprotein-cholesterol (HDL-c) from the serum was carried out for ascertaining hyperlipidemia. Biogenic CuOnpls (spherical, 88.25 nm diameter) capped with bud extract of Syzygium aromaticum and α-tocopherol were administered in the animals per-oral route. Superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) levels were determined to evaluate antioxidant activity of CuOnpls. The nanoparticles were characterized for surface chemical groups by FTIR and HRLC-MS. The nanoparticles revealed novel surface groups responsible for site-specific delivery and beneficial effects. Diabetic rats showed enhanced serum BG, TC, TG and LDL levels and reduction in levels of HDL-c, SOD, CAT and GSH. Administration of CuOnpls caused significant reversal of the effects of diabetes on lipid profile and oxidative stress enzymes. The results pointed to the beneficial effects of CuOnpls for management of post-diabetes complications.

Critical role of the composition of the cell culture medium on cell attachment and viability on PLA biocomposite scaffolds under in vitro assay conditions

In tissue engineering applications 3D scaffolds undertake the function of the native extracellular matrix (ECM) for cell attachment, survival, proliferation, and differentiation. For successful long-term implementation scaffolds need to mimic the ECM in vitro and in vivo. Many studies have focused on protein adsorption as the most critical factor for cell attachment. To improve protein adsorption on polymeric scaffolds various physical and chemical surface modification techniques, such as changing surface porosity, surface energy, and introducing various functional surface chemical groups have been investigated. It is well studied and documented that complex interactions between the biomaterial surface and the cell culture components in in vitro assay conditions define the scaffold performance. In this study influence of in vitro assay components on HepG2 liver cell attachment and proliferation on 3D printed poly(lactic acid) (PLA) scaffolds coated with various polymeric electrospun webs were investigated. MTT assays were performed on the scaffolds by using 3 different cell culture media; (i) basal cell culture medium (DMEM), (ii) DMEM supplemented with 10% albumin, and (iii) DMEM supplemented with 10% fetal bovine serum (FBS). Results obtained have shown dramatic improvement in cell attachment and proliferation in DMEM supplemented with 10% FBS when compared with DMEM and DMEM containing 10% albumin. Our findings clearly demonstrate synergistic effects of all bioactive components present in the FBS medium in significantly improving the HepG2 cell attachment and proliferation on polymeric scaffolds under in vitro conditions, regardless of the substrate structure, composition, and surface properties.

Study on the adsorption performance of Cu2+ in wastewater by red mud

The treatment of copper-nickel wastewater has consistently posed a challenging problem in the field of environmental protection. In this experimental study, the adsorbent used was prepared from Bayer's method-derived red mud (RM). The adsorption characteristics of RM adsorbent on Cu2+ in copper-nickel wastewater, as well as the impact of Ni2+ on the removal effectcy of Cu2+, were investigated. The adsorption performance of Cu2+ in copper-nickel wastewater by adsorbent dosage, adsorption time and pH were investigated, and the adsorption mechanism was discussed. The adsorption process conformed to the pseudo-second-order kinetic model (R2 =0.986) and the Langmuir model (R2 =0.989), indicating that it was a monolayer chemical adsorption process. The raw materials were characterized using various techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray fluorescence (XRF). The results indicated that the adsorption process of Cu2+ and Ni2+ on RM was primarily influenced by surface chemical groups such as O-H, C-O-C, Si-C, and Si-O, among others. The adsorption rate of Cu2+ by RM could achieve 100% when the concentration of Cu2+ solution was 100 mg/L, with an optimal dosage of adsorbent at 0.20 mg/L and the best adsorption effect observed after 240 min. The adsorption of Cu2+ and Ni2+ by RM exhibits unidirectional competitive adsorption behavior. Furthermore,in competitive adsorption experiments, RM exhibits good selectivity towards Cu2+, with Ni2+ exhibiting minimal inhibitory effect on Cu2+ when the two elements coexist. Therefore, this paper offers potential research value for the large-scale application of RM in copper-nickel wastewater treatment processes.

Fabrication of silica/calcium alginate nanocomposite based on rice husk ash for efficient adsorption of phenol from water.

The current work discusses the synthesis of three different solid adsorbents: silica nanoparticles derived from rice husk (RS), calcium alginate beads (AG), and silica/alginate nanocomposite (RSG). The fabricated solid adsorbents were characterized by using different physicochemical techniques such as TGA, XRD, nitrogen adsorption/desorption analysis, ATR-FTIR, pHPZC, SEM, and TEM. The adsorption efficiencies of the prepared solid adsorbents were considered for the removal of phenol as a selected hazardous pollutant. Because of its improved adsorption capacity and environmentally friendly character, a composite made of biosilica nanoparticles and naturally occurring alginate biopolymer by click chemistry is significant in environmental treatment. Adding silica nanoparticles to the alginate biopolymer hydrogel has many advantages, including increased surface area, easier recovery of the solid adsorbent, and additional surface chemical functional groups. The silica/alginate nanocomposite showed surface heterogeneity with many chemical functional groups present, whereas silica nanoparticles had the highest surface area (893.1 m2 g-1). It has been found that the average TEM particle size of RS, AG, and RSG was between 18 and 82 nm. RSG displayed the maximum adsorption capacity of phenol (100.55 mg g-1) at pH 7 and 120 min as equilibrium adsorption time. Adsorption of phenol onto the solid adsorbents fit well with a nonlinear Langmuir isotherm with favorable adsorption. Kinetic and thermodynamic studies prove that the adsorption process follows a pseudo-second-order kinetic model, endothermic process, physical, and spontaneous adsorption. Sodium hydroxide is effective in desorbing 94% of the loaded phenols, according to desorption investigations. Solid reusability tests showed that, after seven cycles of phenol adsorption/desorption, RSG lost only 8.8% of its adsorption activity.

Isomerization of surface functionalized SWCNTs and the critical influence on photoluminescence: static calculations and excited-state dynamics simulations.

Single-walled carbon nanotubes (SWCNTs) functionalized with sparse surface chemical groups are promising for a variety of optical applications such as quantum information and bio-imaging. However, the luminescence efficiencies and stability, two key aspects, undoubtedly govern their practical usage. Herein, we assess the surface migration of oxygen and triazine groups on as-modified SWCNT fragments by adopting transition state theory and explore the de-excitation of oxygen-functionalized SWCNT fragments by performing non-adiabatic excited-state dynamics simulations. According to the predicted moderate or even small reaction barriers, the migration of both oxygen and triazine groups is feasible from an sp3 defect configuration forming an energetically more stable sp2 configuration at moderate or even room temperatures. Such isomerization leads to drastically different light emission capabilities as indicated by the large or zero oscillator strengths. During the dynamics simulations, the lowest excited singlet (S1) state rapidly decays in energy within 20 fs and then fluctuates until the end, providing insights into the emission mechanism of SWCNTs. This study highlights the potential intrinsic limitations of surface-functionalized SWCNTs for luminescence applications.

Novel application of nanomedicine for the treatment of acute lung injury: a literature review.

Nanoparticles have attracted extensive attention due to their high degree of cell targeting, biocompatibility, controllable biological activity, and outstanding pharmacokinetics. Changing the size, morphology, and surface chemical groups of nanoparticles can increase the biological distribution of agents to achieve precise tissue targeting and optimize therapeutic effects. Examples of their use include nanoparticles designed for increasing antigen-specific immune responses, developing vaccines, and treating inflammatory diseases. Nanoparticles show the potential to become a new generation of therapeutic agents for regulating inflammation. Recently, many nanomaterials with targeted properties have been developed to treat acute lung injury/acute respiratory distress syndrome (ALI/ARDS). In this review, we provide a brief explanation of the pathological mechanism underlying ALI/ARDS and a systematic overview of the latest technology and research progress in nanomedicine treatments of ALI, including improved nanocarriers, nanozymes, and nanovaccines for the targeted treatment of lung injury. Ultimately, these nanomedicines will be used for the clinical treatment of ALI/ARDS.

Chemical Scissors Tailored Nano-Tellurium with High-Entropy Morphology for Efficient Foam-Hydrogel-Based Solar Photothermal Evaporators

HighlightsPrecise exfoliation and modification of nano-Tellurium was realized by adopting a room-temperature ionic liquid as the electrolyte.Nano-Tellurium with high-entropy morphology can offer greater solar absorption and more kinds of surface chemical groups, giving rise to superior photothermal properties.Nano-Tellurium-poly(vinyl alcohol)-based photothermal foam hydrogels, with high compressibility, excellent water transport rate and low evaporation enthalpy of water, combined with a new heat-supply model, achieve an evaporation rate of 4.11 kg m−2 h−1 with energy efficiencies up to 128% under 1 sun irradiation, which are the highest values for semiconductor-based nanocomposites reported so far.

Deterioration of single-use biodegradable plastics in high-humidity air and freshwaters over one year: Significant disparities in surface physicochemical characteristics and degradation rates

More single-use plastics are accumulating in the environment, and likewise biodegradable plastics (BPs), which are being vigorously promoted, cannot escape the fate. Currently, studies on the actual degradation of BPs in open-air and freshwaters are underrepresented despite they are potentially headmost leakage and contamination sites for disposable BPs. Herein, we compared the degradation behavior of six BP materials and non-degradable polypropylene (PP) plastics over a 1-year in situ suspension in the high-humidity air, a eutrophic river, and an oligotrophic lake. Moreover, a 3-months laboratory incubation was performed to detect the release of dissolved organic carbon (DOC) from BPs. In both air and freshwaters, poly(p-dioxanone) (PPDO) degraded significantly while PP and polylactic acid (PLA) showed no signs of degradation. The average degradation rates of three poly(butylene adipate-co-terephthalate) (PBAT)-based films varied: 100% in river, 55% in lake, and 10% in air. In addition to PLA, surface chemical groups, hydrophilicity, and thermal stability of BPs changed, and microplastics were found on their surfaces. Correspondingly, BPs with faster degradation rates released relatively higher amounts of DOC. Environmental microbial and chemical characteristics may contribute to differences in BP degradation besides polymer specificity. Altogether, our results indicate the need for appropriate monitoring of BPs.