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Advanced oxidation processes (AOPs) present one of the most promising strategies to deal with the ever-growing water pollution. However, fabricating improved catalysts with large size (meter level or larger), long-term stability, and adequate activity is still a formidable challenge in practical applications. In this study, cobalt ions are covalently linked on the polypropylene nonwoven fabric (P-PFeCo) via irradiation graft polymerization and used as highly efficient and stable reaction sites to degrade highly toxic and difficult biodegradable organics by activating peroxymonosulfate (PMS). The presence of graft chains not only generates a well-defined monometallic reaction microenvironment, but also promotes electron transfer. The as-prepared catalyst combines these exceptional properties for efficient removal of dyes or antibiotics via activating PMS within 8 min and exhibits remarkable durability over a wide pH range and recyclability after five consecutive runs with trace cobalt leaching. The X-ray absorption fine structure (XAFS) spectroscopy and density functional theory (DFT) calculations reveal that the CoN4(H2O)2 site acts as an active site for activating PMS. A device in a flow mode is also constructed to illustrate the potential applications of P-PFeCo. We consider that the catalytic process along with the large-sized substrate will broaden a new horizon in terms of designing high-performance catalysts for PMS activation in wastewater treatment.

A new technique is proposed for the in situ printing of fluorescent fabrics with superior fluorescent properties that have the potential for continuous roll-to-roll production in the industry. Nonconjugated chemical moieties were covalently connected to polyethylene/polypropylene nonwoven fabric (PE/PP NWF) to successfully prepare fluorescent PE/PP NWF, which emits a bright blue light and has a high quantum yield (∼83.35%) that can be attributed to a unique aggregation-induced emission effect. The fluorescent PE/PP NWF exhibits excellent fluorescent stability under high shear forces during accelerated laundering and in harsh chemical environments. The fluorescent PE/PP NWF can also be tailored into diverse shapes and printed in situ with high resolution. The versatility of the method was also demonstrated by fabricating fluorescent materials with different polymer matrices such as Nylon 66 fiber and PE terephthalate membrane.

Immobilization of photocatalysts on substrates is an important factor for water purification in practical applications. In this study, an efficient Ag@AgBr photocatalytic coating was attached onto the surface of cotton fabric via radiation-induced graft polymerization and subsequent chemical reactions, and the resultant product was denoted as Cot-Ag@AgBr. The graft chains acted not only as a source of bromine, but also as an intermediate layer to anchor the Ag@AgBr photocatalytic coating via strong electrostatic interactions. The immobilized Ag@AgBr photocatalytic coating exhibited outstanding photocatalytic properties for organic dye degradation under visible light irradiation. Furthermore, Cot-Ag@AgBr presented high stability and robust durability, which conferred its excellent visible-light-driven photocatalytic activity after five rounds of photodegradation. After 10 min of ultrasonication, the amount of Ag@AgBr precipitate that leached from the Cot-Ag@AgBr was

Textiles with fire detection will appeal for the interior decoration of houses and play a critical role in public security. Herein, we fabricated a sandwichlike fire alarm fabric (Ag@Fe3O4-MS) base...

A new amidoxime-functionalized ultrahigh molecular weight polyethylene fibrous adsorbent (UHMWPE-g-PAO) was used for the recovery of Au(III) from acid aqueous solution. The maximum experimental absorption capacity of UHMWPE-g-PAO fiber was found to be approximately 220.0 mg·g−1. Au adsorption on UHMWPE-g-PAO was characterized by synchrotron radiation-based microcomputed tomography (SR-μ-CT), transmission electron microscopy (TEM), X-ray absorption near-edge structure spectroscopy (XANES) and synchrotron radiation-based Fourier transform infrared microspectroscopy (SR-FTIR). The SR-μ-CT and TEM results showed the distribution features of gold particles on the fiber. The mechanism of Au(III) recovery from aqueous solutions by UHMWPE-g-PAO was based on the adsorbed Au(III) ions, which were reduced to metallic zero-valent gold (Au(0)) by amino groups (–NH2) in the amidoxime (AO) groups during the adsorption process, as confirmed by high-resolution TEM (HRTEM) and XANES analyses. X-ray diffraction (XRD) results indicated that the incineration ashes contained metallic zero-valent gold. In conclusion, this amidoxime-functionalized fibrous adsorbent is a promising material for recovering gold from aqueous solution.

In this study, free radicals in polyacrylonitrile (PAN) fibers induced by irradiation of 500-keV electron beam (EB) accelerator were investigated via electron spin resonance (ESR). Alkyl radicals and polyimine radicals were formed in PAN fibers after irradiation, and the relative content of the two free radicals changed with respect to the absorbed dose and dose rate. The effect of temperature on the relative content of the two radicals was investigated via analyzing the ESR spectra of alkyl radicals and polyimine radicals, and two parameters (PHR and δPHR) were set for evaluation. The value of δPHR was related to the temperature. The instantaneous temperature change in the PAN fibers during the irradiation process was inferred via analyzing the change in δPHR. Changes in the free radicals in irradiated PAN fibers during the stabilization process were also understood by ESR. Irradiation induced cross-linking and decreased the temperature of pre-oxidation for the PAN fibers. Increases in the dose rate of EB irradiation efficiently induced cross-linking and also led to pre-oxidation of the PAN fiber due to heat accumulation by EB irradiation. Radiation crosslinking significantly reduced the temperature required for peroxidation, and the trend was more evident at higher dose rates. For example, the PAN fiber irradiated to 400 kGy at a dose rate of 2 kGy/s was pre-oxidized at approximately 150 °C while the PAN fiber irradiated to 400 kGy at a dose rate of 13 kGy/s exhibited a darker color and was pre-oxidized at approximately 130 °C.

A bifunctional interfacial layer was introduced onto the surface of cotton fabric which not only enhanced the interfacial bonding between Ag@ZnO and organic substrates but also improved the photocatalytic performance simultaneously. In detail, a modified cotton fabric (denoted as Cot-g-Si/Ag@ZnO) was fabricated through radiation-induced graft polymerization of γ-methacryloxypropyl trimethoxysilane and followed the in-situ formation of ZnO and loading of Ag nanoparticles simultaneously. Owing to ZnOSi between the graft chains and Ag@ZnO photocatalyst, the charge carrier concentration increased and Ag was prevented from oxidizing through the partial separation from ZnO, leading to enhanced near-field amplitudes of the localized surface plasmon resonance. Cot-g-Si/Ag@ZnO also exhibited excellent photocorrosion resistance, photostability and laundering durability. Its photocatalytic activity was fully maintained after several photodegradation cycles; moreover, after laundering durability test, the photocatalytic activity was improved compared with the newly prepared one. Credible mechanism for the photocatalytic activity of Cot-g-Si/Ag@ZnO under sunlight irradiation is proposed.

Varieties of microorganisms in seawater exhibit negative effects on the performance of adsorbents in uranium uptake from seawater. In this study, a novel adsorbent with excellent antifouling proper...

Replacement of CH4 with CO2 in gas hydrates is a promising option for producing CH4 and sequestrating CO2 simultaneously, but it remains debatable if the CH4 hydrate dissociates or converts to the ...

A new kind of highly durable, electrically conductive UHMWPE fibers coated with copper was fabricated through a novel, simple, and universal process in this paper. Poly(acrylic acid) was anchored o...

The partial least square method (PLS) was introduced to quantitatively analyze component content of multivariate mixture by using ultraviolet-visible spectroscopy. Two models were built to establish component content of multivariate mixture based on the transmittance spectra of multivariate mixture, which is the full band PLS model and the feature band iPLS model, respectively. The comparative study of the models was carried out with ethanol solution as the research object and the samples were divided into two groups, including the calibration sets and the prediction sets. This study indicates that there is a certain relationship between the spectra information of the multivariate mixture and its component content, and the above two models are feasible for solving the component content. Compared with the full band PLS model, the feature band iPLS model has higher accuracy and the model is simpler. Therefore, the feature band iPLS model, which is an efficient method, can be used to analyze the component content in multivariate mixture solution based on the ultraviolet-visible spectrum.

A self-shielded electron beam (EB) accelerator was connected to the front of a pre-oxidation furnace to evaluate the effect of radiation on the pre-oxidation of polyacrylonitrile (PAN) fibers; with this setup, PAN fibers could be irradiated and pre-oxidized in sequence to obtain stabilized fibers. Radiation effects during different temperature stages of the pre-oxidation process were analyzed by differential scanning calorimetry, Fourier-transform infrared spectroscopy, and electron spin resonance spectroscopy. The results indicated that radiation exerted significant but different effects at various stages of the pre-oxidation process. The alkane radicals induced by radiation are rapidly transformed into polyene structures and produced polyenyl radicals after a short heat treatment period. The polyenyl radicals promoted dehydrogenation and cyclization reactions and polyene structures improved the thermal stability of the PAN fibers. Therefore, radiation can greatly shorten the time required for the stabilization of PAN fibers, owing to which the time needed for each temperature stage can be reduced by a large extent. The effects of radiation on various temperature stages of the pre-oxidation process were analyzed accurately by studying the changes in the concentration of polyenyl radicals. An optimized pre-oxidation process for irradiated PAN fibers was designed, which reduced the time period required for stabilization by 75%. The optimized pre-oxidation plus continuous EB irradiation process induced good properties in the stabilized PAN fibers, in terms of fiber density, oxygen content, and degree of cyclization. Radical concentration was found to be an appropriate indicator to express the degree of pre-oxidation.

Microsecond molecular dynamics simulations were performed to investigate the methane hydrate formation on smooth and rough metal surface covered with water, light oil, and heavy oil with asphaltenes, respectively. The growth and crystallization of methane hydrates were characterized by the four-body order parameter and the face-saturated incomplete cage analysis. Results highlighted the priority for hydrate growth inside the groove of rough metal surface, from which the hydrate grew upwards to the outside of the groove and then to the water-gas interface. It clearly demonstrated the inhibition effects of light oil on the methane hydrate growth, which was further enhanced by adding asphaltenes. The inhibition mechanisms were elaborated during different stages of hydrate growth by gaining insights into the four-body order parameters at different locations of metal surface. To our knowledge, this was the first molecular-level study on the methane hydrate evolution on metal surface with heavy oil. It provided theoretical supports for evaluating the priority sites for the hydrate formation on pipe wall with concave and convex surfaces that might result from metal corrosion, change of pipe diameter or depositions of solid particles during the multi-phase transportation.

The hazardous effects of petroleum contaminants in the soil and water environment are highly associated with their interactions with cellular membranes, but our understanding on the molecular-level mechanisms for the adsorption and penetration of heavy oil mixture on cellular membrane is very limited. In this study, microsecond molecular dynamics simulations were performed to gain insights into the morphological evolution and penetration dynamics of the multi-component and single-component oil droplets on the dipalmitoylphosphatidylcholine lipid membrane. Results highlighted the inhibition effect of the resins on the penetration of alkanes and aromatics, because they would form net structure making it difficult to release the latter two components from the oil droplet to the membrane. It also demonstrated the obviously different patterns of penetration between alkanes and aromatics. The overall steps for the toluene penetration included detachment from oil droplet, dispersion in water, adsorption on membrane surface, structure adjustment and penetration into membrane. By contrast, the step of dispersion in water was not necessary for the alkanes' penetration. Instead, it relied on the adsorption of the whole oil droplet on the membrane surface which resulted in the formation of pores on the membrane surface by local structure deformation in the lipid head group regions.

Gas hydrates in marine sediments are promising energy resources, while an effective recovery of methane from clay pores relies on a comprehensive appreciation of the hydrate evolution inside and outside the pore especially at a saline environment. Molecular dynamics simulations were conducted to investigate the methane hydrate formation and dissociation in the sodium montmorillonite (Na-MMT) interlayer with fresh water and saline water, respectively, by characterizing the distribution and transportation of methane and ions (K+, Na+, and Ca2+), the overall and local four-body structural order parameter, and the radial distribution functions. Results indicated that it was much easier to form methane hydrates in the bulk water than in the pore water, while the hydrates in the pore region were more readily dissociated than in the bulk region. The effects of salt ions on the hydrate formation were opposite in these two regions, which highlighted the role of the salting-out effect and the ion exchange between b...

A method of earlier crystallization was applied to prepare high-performance polypropylene (PP) foam using supercritical CO2 (scCO2) with the addition of a composite nucleating agent (CNA). Increased crystallization point and decreased crystal size of PP were obtained in the presence of CNA. Earlier crystallization induced cell formation in an early stage of foaming; this, combined with enhanced heterogeneous nucleation caused by microcrystal growth, resulted in well-defined cellular structure. The cell size of PP/CNA foam decreased from 87 to 30 μm, and the cell density was more than 20 times that of the neat PP foam. Moreover, the first compression stress of PP/CNA foam increased from 125 to 180 kPa compared to neat PP foam. We proposed that earlier crystallization promoted the emergence of a large number of microcrystals at the beginning of the foaming process, which effectively suppressed cell growth and prevented cell rupture and collapse.

The in situ growth of one-dimensional magnetite (Fe3O4) nanowire (NW) arrays with deterministic and tunable control over their orientation and morphology on a wide range of flexible and low heat resistance substrates is still a challenge. Herein, a facile method of controlling the orientation of Fe3O4 NW arrays on a polypropylene (PP) nonwoven fabric surface (PP-g-PAO/Fe3O4) through simultaneous radiation induced graft polymerization and coprecipitation processes was realized. We demonstrated a control over the orientation and geometric properties of coprecipitated Fe3O4 NWs via complex iron ion using amidoxime groups, which not only endow the material with high durability but also lead to the oriented growth of Fe3O4 NWs. The results showed that Fe3O4 NWs were only grown on the surface of the PP nonwoven fabric (length:diameter ratio ≈ 10), whereas the Fe3O4 produced in the solution exhibited a spherical structure under identical conditions. The PP-g-PAO/Fe3O4 composite presented a good saturated magneti...

Molecular dynamics (MD) simulations and optical contact angle measurements were performed to shed light on the microscopic mechanisms for the dynamic wetting of heavy oil on rough silica surfaces. The surface wetting process was characterized by interaction energy, wettability transition, density profile, and penetration of each oil fraction, while competitive adsorption between oil and water droplets on rough surfaces was also investigated. Results highlighted the role of asphaltenes on the distribution and penetration of resins and aromatics, which might become either a driving force or mass transfer resistance for the wettability transition on rough surfaces. The competitive adsorption process was divided into three steps including water bridge formation, water penetration, and oil penetration. Water penetration promoted oil penetration by providing a channel for asphaltene invading. The overall tendency of simulation results agreed with experimental observations. To our knowledge, this was the first a...

Gas hydrate formation and asphaltene aggregation are two major concerns for flow assurance in the petroleum industry, whereas the atomistic understanding of their interactions remains limited, especially in the oil-dominated systems. Microsecond molecular dynamics simulations were performed to investigate the combined effects of solvent type, water droplet size, and asphaltenes on methane hydrate formation in a model water-in-oil emulsion by characterizing the four-body structural order parameter, molecular configurations, and evolution of hydrate cages. The results indicated the faster hydrate formation in a small water droplet with n-heptane because of the decreased interfacial curvature. Meanwhile, hydrate growth was promoted in a large water droplet with toluene because of the occurrence of a vertical water channel, which provided an extra growth site. The results also demonstrated the inhibition effect of asphaltenes on hydrate formation, which was more pronounced in a small droplet with n-heptane or...

The particle swarm optimization (PSO) was introduced to calculate optical constants of liquid based on transmittance and reflectance spectrum. Two methods, namely as particle swarm double-thickness transmittance method (PTT) and particle swarm transmittance and reflectance method (PTR), were developed by combining the PSO with the spectrometry. The comparative study of two methods was carried out with distilled water as the research object, and the experimental deviation of the two methods was evaluated. The results show that the two methods are reliable for solving optical constants of liquid with high resolution accuracy, even existing experimental deviation. Meanwhile, a deviation correction method proposed in present work reduces the effect of uneven experimental deviation on the accuracy of the two methods.

Herein we report a simple and reproducible method for fabricating highly durable and robust superhydrophobic and superoleophilic cotton fabrics via simultaneous radiation-induced graft polymerization of glycidyl methacrylate and subsequent chemical modifications with aminopropyltriethoxysilane and hexamethyldisilazane. The chemical structure and the surface topography of the pristine and the modified cotton fabrics were investigated in detail by ATR-FTIR, XPS, and 29Si NMR, and a grafting layer was successfully immobilized onto the surface of the cotton fabric by forming covalent bonds. Multi-dimensional surface roughness was created by combining micro-sized fibers of the cotton fabric, nanoscaled protuberances of the grafting chain, and molecular level spherical projection points of silicon methyl. The superhydrophobic cotton fabric exhibited long-term stability, ultra-high durability and robustness, and maintained its properties even after 25 wash cycles. The fabric also showed excellent water repellency with a water contact angle of 153 ° and a high efficiency of oil/water separation (98 %). The superhydrophobic/superoleophilic cotton fabric developed in the present work exhibits important potential applications in superhydrophobic textiles and oil/water separation.

The surface of Kevlar fibers was successfully modified by electron beam (EB)-induced post-grafting of acrylic acid (AA). The generation of radicals in the fibers was confirmed by electron spin resonance (ESR) measurements, and the concentration of radicals was shown to increase as the absorbed dose increased, but decrease with increasing temperature. The influence of the synthesis conditions on the degree of grafting was also investigated. The surface microstructure and chemical composition of the modified Kevlar fibers were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The SEM images revealed that the surface of the grafted fibers was rougher than those of the pristine and irradiated fibers. XPS analysis confirmed an increase in C(O)OH groups on the surface of the Kevlar fibers, suggesting successful grafting of AA. These results indicate that EB-induced post-grafting polymerization is effective for modifying the surface properties of Kevlar fibers.

An innovative ultrahigh molecular weight polyethylene (UHMWPE) fibrous adsorbent was successfully synthesized via radiation grafting and applied to the selective capture of palladium ions from dilute aqueous solutions. The influence of the pH, initial Pd(II) concentration, and temperature on the adsorption performance was examined in a batch adsorption experiment. Pd K-edge extended X-ray absorption fine structure (EXAFS) spectra indicated that Pd(II) was immobilized on the adsorbent surface via a ligand exchange reaction that formed a stable UHMWPE-PMDA-Pd complex. Although the concentrations of coexisting ions (Cu(II), Zn(II), Cr(VI), Fe(III), and Ni(II)) in the solution were much higher than that of Pd(II), the adsorption capacity for Pd(II) of the as-prepared absorbent was significantly greater than that for other metal ions. Kinetic studies showed good correlation with the pseudo-second-order model. The maximum capacity for Pd(II) adsorption was approximately 221.8 mg·g −1 at 298 K. The adsorption behavior conformed to the Langmuir isotherm model. Thermodynamic studies revealed that the adsorption of Pd(II) was a feasible, spontaneous, and endothermic process.

The present study sheds some light on the long-standing debate concerning the coordination properties between uranyl ions and the amidoxime ligand, which is a key ingredient for achieving efficient extraction of uranium. Using X-ray absorption fine structure combined with theoretical simulation methods, the binding mode and bonding nature of a uranyl–amidoxime complex in aqueous solution were determined for the first time. The results show that in a highly concentrated amidoxime solution the preferred binding mode between UO22+and the amidoxime ligand is η2coordination with tris-amidoximate species. In such a uranyl–amidoximate complex with η2binding motif, strong covalent interaction and orbital hybridization between U 5f/6dand (N, O) 2pshould be responsible for the excellent binding ability of the amidoximate ligand to uranyl. The study was performed directly in aqueous solution to avoid the possible binding mode differences caused by crystallization of a single-crystal sample. This work also is an example of the simultaneous study of local structure and electronic structure in solution systems using combined diagnostic tools.

The optical properties of polyacrylamide(PAM) solution play an important role in measuring PAM concentration of the solution in the polymer flooding of oilfield based on optical methods. Transmittance spectra of optical cell filled with PAM solution in the infrared wavenumber range from 400 to 4000 cm−1 at normal incidence were measured at the temperature range of 20–70 °C by an infrared spectrometer IRTracer-100. Then the optical constants of PAM solution were calculated by the transmission method combined with Kramers-Kronig(K-K) relation. The results show that the absorption index of PAM solution decreases with solution temperature increasing, and the values of absorption index of PAM solution are in the range of 1.56E-3–5.83E-3. The refractive index of PAM solution increases with the increase of temperature, and the values of refractive index of PAM solution are in the range of 1.32–1.38.

Molecular dynamics simulation was performed to investigate the adsorption and aqueous extraction of oil contaminants on silica surface with various roughness. The oil dispersion and immersion were characterized by molecular configuration, adsorption energy and contact angle, while the oil detachment in water and cyclodextrin solution was evaluated by the overall extractability, extractability from individual groove and free energy analysis. Results demonstrated that the main resistance for oil release from the relatively shallow grooves was the strong intermolecular interactions among the oil molecules orderly stacked inside the grooves. It highlighted the role of cyclodextrin in breaking through the energy barrier for pulling out one oil molecule from the tightly stacked oil structure, which resulted in the fast release of the remaining oil. Previous studies attributed the oil extraction to the sequestration of oil into the hydrophobic cavity of cyclodextrin, while our results demonstrated that such incl...

Ultrahigh-cell-density polypropylene (PP) foam was prepared by supercritical carbon dioxide (scCO2) foaming in the presence of porous polytetrafluoroethylene (PTFE) micropowder. The voids of PTFE m...

Natural gas hydrate is a promising energy resource, but it is challenging to recover methane from the clay pores rich with sediment organic matter due to the inadequate information on hydrate evolution in the organoclay complex. Molecular dynamics simulations were conducted to investigate the methane hydrate formation and dissociation in the sodium montmorillonite interlayer (Na-MMT) with fatty acids by characterizing the four-body structural order parameter, radial distribution functions, and cage types. Results demonstrated the slight inhibition of fatty acid types (butyric and isovaleric acid) at molar concentrations (0.6% and 1.5%) on the methane hydrate formation in the context of this study. This finding was a result of several main processes including the formation of “quasihydrate” water structures around the hydrophobic carbon chains of fatty acids, the disruption of hydrogen bond networks by the hydrophilic carboxyl of fatty acids, and the restriction on the thermal motion of the sodium ions by ...

Free dispersion of natural gas in the air environment possibly produces explosion and subsequent fire, which has a fatal harm to people's life. The accidental leakage of natural gas pipeline is one of the main productions for natural gas in air environment, and laser technology is a method to detect natural gas pipeline leakage. In this study, the effect of leaking natural gas dispersion on the laser detection was numerically investigated. Four factors effect on natural gas dispersion and intensity of laser detection were also analyzed including leakage aperture, leakage velocity, detection distance, and leakage time. The results show that the spectral detection value decreases by 3.72% at high-speed leakage, 2.74% at medium-speed leakage, and 0.46% at low-speed leakage, when detection distance increases by 10% in the vertical direction of leak hole. Detection time and leak hole both has a large influence on laser detection intensity in high-speed leakage compared with two others. This research results can provide a help for the safe evaluation of gas pipeline emergency.

Because polypropylene (PP) foam normally exhibits nonuniform cell size and cracked cellular structure, a narrow cell-size distribution and a well-defined morphology are always the focus of PP foaming technology. In this work, hollow molecular-sieve (MS) particles were applied as a potential nucleating agent in supercritical carbon dioxide (scCO2) foaming of PP. It was observed that the addition of MS particles largely narrowed the cell-size distribution. The resultant PP/MS foams exhibited significant concurrent enhancement in their cell density and mechanical properties: the cell density increased remarkably, by approximately 10 times, and the tensile strength increased from 6.1 MPa to 12.6 MPa. The hollow-structure MS particles resulted in a higher heterogeneous nucleation efficiency in the PP foaming process. We believe that the trapping of CO2 in the hollow holes of MS particles largely increased the solubility CO2 in PP and a number of gas cavities were formed. The existence of gas cavities reduced the energy barrier of heterogeneous nucleation, favoring the formation of a well-defined cellular structure. Additionally, the regular-hexagon shape of the cells might endow the PP foam with better mechanical properties compared with a circular cell shape.

Using a facile strategy to prepare multifunctional cotton fabrics with switchable superhydrophobicity–superhydrophilicity, UV-resistance, photo-induced water–oil separation, and self-cleaning properties is an important and urgent issue in the sustainable development of natural fibers. Herein, a new type of surface modified cotton fabric with a polysiloxane–TiO2 hybridized coating (Cot-g-PMAPS/TiO2) was prepared through radiation-induced graft polymerization and sol–gel technology. The hybridized coating was composed of two sub-layers: an inner part consisting of an organic–inorganic hybrid layer to address the issue of self-degradation of TiO2-loaded polymeric materials while simultaneously improving the adhesion of the TiO2 film to its support, and an outer part consisting of nanocrystalline anatase TiO2 to endow the cotton fabric with multifunctionality. The influence of the polysiloxane–TiO2 on the structure and integrated performance of Cot-g-PMAPS/TiO2 was systematically studied. The results showed that the polysiloxane–TiO2 coating improved the UV absorption capacity 5.6-fold compared with that of the untreated cotton fabric. In addition, the retention of the break strength of Cot-g-PMAPS/TiO2 was 95.6% after 192 h of UV irradiation. Since the polysiloxane–TiO2 coating is chemically bound to the cotton fibers, the Cot-g-PMAPS/TiO2 fabric possesses long-term stability, ultra-high durability, and robustness. After 20 commercial or domestic launderings, the UV absorption intensity and WCAs were almost the same as those of the newly fabricated material. The Cot-g-PMAPS/TiO2 also exhibits photo-induced water–oil separation and self-cleaning based on the switchable superhydrophobicity–superhydrophilicity and the photoactivity of TiO2. This study provides an interesting insight into the design of a novel functional material based on a controllable surface structure.

A blend of isotactic polypropylene (PP) with high-density polyethylene (HDPE) in different PP/HDPE ratios was irradiated by γ-ray to induce cross-linking and then foamed using supercritical carbon dioxide (scCO 2 ) as a blowing agent. Radiation effect on the melting point and crystallinity were analyzed in detail. The average cell diameter and cell density were compared for PP/HDPE foams prepared under different conditions. The optimum absorbed dose for the scCO 2 foaming of PP/HDPE in terms of foaming ability and cell structure was 20 kGy. Tensile measurements showed that the elongation at break and tensile strength at break of the crosslinked PP/HDPE foams were higher than the non-crosslinked ones. Of particular interest was the increase in the foaming temperature window from 4 ℃ for pristine PP to 8–12 ℃ for the radiation crosslinked PP/HDPE blends. This implies much easier handling of scCO 2 foaming of crosslinked PP with the addition of HDPE.

CH4 hydrate have been considered as the future clean energy resource. Recovery of CH4 from natural gas hydrates by CO2 replacement is a promising method for energy harvest and CO2 sequestration. Field production tests have proved the feasibility of gas production by CO2 replacement in the permafrost region. However, most of the hydrate reservoirs are located at marine conditions where pressure and temperature conditions are not favorable for the replacement process. In this work, we identified a possible marine condition, where mixed hydrates could potentially form. We investigated the technical feasibility of CH4 recovery by a depressurization process followed by the injection of CO2-N2 gas. To quantify the dynamic behavior of mixed hydrates formation and dissociation, we developed a numerical method to estimate the phase partitioning during the replacement process. The effects of mixed gas compositions in the reactor on the replacement efficiency were investigated. Our experimental results showed that rapid co-growth of mixed hydrates occurs when the injected gas composed of a lower N2 concentration (

Several co-monomers were co-grafted with acrylonitrile onto polyethylene nonwoven fabric to prepare amidoximated sorbents. The grafted co-monomer was found to play an important role in the uranium adsorption capacity and sorption selectivity of amidoximated sorbent in natural seawater in the following order: acrylamide (AAm)

A highly effective antimicrobial nylon 66 fiber doped with permanganate ions was prepared via a simultaneous irradiation induced graft polymerization. The physicochemical properties of the fibers were carefully characterized by various techniques, including Fourier-transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy, revealing that permanganate ions (about 1.48 mmol/g) have been successfully loaded onto the surface of the nylon 66 fibers. The antimicrobial activity of the modified nylon 66 fibers against Staphylococcus aureus and Candida albicans were investigated. Accelerated laundering tests and tensile tests were conducted to access the effect of laundering on the antimicrobial activity and the mechanical property of the modified nylon 66 fibers, respectively. All results indicate that we have prepared a new highly effective antimicrobial nylon 66 fiber (almost a 100% reduction in the number of S. aureus and C. albicans colonies). Furthermore, the modified nylon 66 fibers are durable, maintaining antimicrobial resistance after 100 commercial or domestic launderings and retaining its excellent mechanical property during preparation and laundering.

A new functionalized ultrahigh molecular weight polyethylene-based chelating fiber (UHMWPE-AM) for trace uranium extraction from wastewater was synthesized by preirradiation grafting modification. Adsorption behavior of adsorbent was examined under varying conditions like solution pH, contact time, initial ion concentration and adsorbent dose. The results showed the maximum removal of U(VI) was 99.7% at pH 4. Adsorption isotherm was in agreement with Langmuir isotherm equation with the maximum monolayer adsorption capacity of 16.56 mg/g, and the pseudo-second-order model can well describe the kinetics process. The dominant coordination mechanism of U(VI) on the UHMWPE-AM fibers was ascribed to inner-sphere surface complexation.

Cyclodextrins were used as environmentally friendly additives to overcome the slow kinetics of hydrate formation that limited the industrial application of gas hydrate technology. Microsecond molecular dynamics simulations were performed to identify the degree and the underlying mechanisms of the cyclodextrin effects on the methane hydrate formation rate by the four-body order parameter and molecular configurations and to clarify the hydrate structure in the presence of cyclodextrin by face-saturated incomplete cage analysis. Overall results indicated that the addition of β-cyclodextrin in water facilitated the hydrate growth rate, promoted the formation of thermodynamically stable hydrate structure, and enhanced the methane storage capacity. It highlighted the role of cyclodextrin to facilitate the formation of water channel bridging hydrate and water (at low ratio of gas to water) and to increase the gas–water interfacial curvature (at high ratio of gas to water) on the accelerated kinetics of hydrate g...

Poly(acrylic acid), poly(sodium styrenesulfonate), and poly(acrylic acid- co -sodium styrenesulfonate) chains were immobilized onto poly(vinyl alcohol) (PVA) particles via a facile γ-ray simultaneous irradiation induced graft polymerization technique, which were confirmed by the attenuated total reflection Fourier transform infrared spectroscopy and the high swelling ratios of modified PVA particles. The effects of absorbed dose, dose rate, Cu 2+ concentration and monomer concentration on the degree of grafting (DG) of PVA particles were investigated to find out a feasible process for preparing polyanionic chains graft-modified PVA particles. The clotting time results illustrated that both PVA- g -PAA and PVA- g -PSSS particles presented excellent anticoagulant activity, and the activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT) were effectively prolonged with the increase of DG AA and DG SSS , respectively. Furthermore, the anticoagulant activity of PVA- g -PSSS samples was more efficient than that of PVA- g -PAA samples. However, the anticoagulant effect of PVA- g -P(AA- co -SSS) samples was different from that of PVA- g -PAA and PVA- g -PSSS samples, and was similar to that of heparin, mainly elongating the APTT and TT. This might be due to both of them containing the same negative-charged groups. Additionally, the grafted PVA particles were all non-hemolytic, showing good blood compatibility.

At present, amidoxime-based adsorbents are considered to be the most promising materials for extraction of uranium from seawater. However, the high concentrations of transition metals especially vanadium strongly compete with uranium in the sequestration process, which is extremely limited the commercial use of amidoxime-based adsorbents. In this work, the coordination modes, bonding nature, and stabilities of possible vanadium(IV) (VO2+) and (V) (VO2 +, VO3+, V5+) complexes with amidoximate (AO−), carboxyl (Ac−), glutarimidedioximate (HA−) and deprotonated glutarimidedioximate (A2−) on single and double alkyl chains (R=C13H26) are systematically explored by quantum chemical calculations. Different from the uranyl (UO2 2+) complexes, the AO− groups of the vanadium(IV) and (V) complexes prefer to coordinate as monodentate and chelate ligands, while few species with AO− groups in η2-binding mode have been observed in the vanadium complexes. Besides, the vanadium complexes are predicted to have obvious covalent metal-ligand bonds. According to thermodynamic stability analysis, all the vanadium complexes with AO−, Ac−, HA− and A2− ligands on double alkyl chains are found to be more stable than corresponding complexes with ligands on a single chain. The synergistic effect of the amidoxime and carboxyl groups can be observed in most of VO2 + and VO3+ complexes with mixed ligands (AO−/Ac−). The vanadium(IV) and (V) complexes are more stable than the corresponding uranyl complexes, and the adsorption capability of the amidoxime-based adsorbents toward vanadium(V) ions decrease in the order of VO2 +>VO3+> V5+. The dioxovanadium cation VO2 + is predicted to form multinuclear vanadium complex in the sequestration process, possibly resulting in higher stable VO2 + complexes. Therefore, the higher complexation ability of the amidoxime-based adsorbents toward vanadium over uranium is probably due to the differences in the coordination modes and bonding nature. The current results might provide important clues for rational design of efficient ligands in sequestration of uranium from seawater.

Atactic polypropylene (PP) samples with melt flow indices (MFI) of 7.0 g/10 min were irradiated and then foamed with supercritical carbon dioxide (scCO2). A detailed investigation was carried out to understand the effect of radiation on the scCO2 foaming of polypropylene. Variations in the molecular weight, branching degree, crystallinity, and melting and crystallization temperatures of irradiated PP were investigated. The cell diameter, cell density, volume expansion ratio and foaming rate were analyzed in detail under different conditions. It was found that the cell structure of PP foam became more uniform and the foaming temperature window increased to 10 °C. This compares favorably to the 4 °C observed with pristine atactic PP. The best cell morphology was observed at a dose of 30 kGy. The corresponding average diameter and cell density were 16.4 μ m and 5.7×107 cells/cm3, respectively.

Uranium recovery from seawater was investigated in simulated seawater in the laboratory and in natural seawater from the coasts of China with different amidoxime-based (AO) ultrahigh molecular weight polyethylene (UHMWPE) fibers. The capacities of adsorbents AO-UHMWPE-1 and -2 were 4.54 and 2.41 mg U/g-adsorbent, respectively, after 24 h of adsorption in the simulated seawater with 330 ppb U. Their capacities were 2.93 and 1.95 mg U/g-adsorbent, respectively, after 42 days of adsorption in simulated seawater flow-through experiments with 3.3 ppb U. However, because of sediment and marine organism contamination, the capacities were 0.25 and 0.04 mg U/g-adsorbent, respectively, after 68 days of adsorption in natural seawater in Xiamen. The capacity of AO-UHMWPE-7 was 1.41 mg U/g-adsorbent after 15 days of adsorption in natural seawater in Daishan. The average capacity of AO-UHMWPE-7 was 1.50 mg U/g-adsorbent, which was 18 times greater than that for V after 15 days of adsorption in natural seawater in Daish...

A novel fibrous adsorbent containing amine and quaternary ammonium groups was prepared by radiation-induced graft of glycidyl methacrylate (GMA) onto ultra-high molecular weight polyethylene (UHMWPE) fiber and further modifying with triethylenetetramine (TETA) and glycidyl trimethylammonium chloride (GTA). The ATR-IR spectra and SEM observation demonstrated that amine and quaternary ammonium groups were immobilized onto the surface of UHMWPE fiber. The principal factors affecting the adsorption of Cr(VI) ions have been investigated including pH of the aqueous solution, contact time, temperature and coexisting anions. This novel fibrous adsorbent could effectively adsorb Cr(VI) in the range of pH 1–9, and the maximum adsorption capacity reached 295 mg/g at pH 3 and 25 °C based on the Langmuir isotherm. It was found that adsorption equilibrium could be achieved within 2 h for initial Cr(VI) of 100 mg/L, following the pseudo-second order model. The effect of coexisting anions (including SO42−, H2PO4−, NO3−and Cl−) on the uptake of Cr(VI) was investigated in detail. Additionally, the adsorption saturated fiber could be regenerated by soaking in 0.5 mol/L NaOH solution, and the adsorption performance of this adsorbent could be maintained at 90% after eight cycles of adsorption-desorption. ATR-IR and XPS analysis revealed that Cr(VI) ions were adsorbed on the fiber adsorbent through ion exchange mechanism.

The electrode reactions and electrolysis process of graphite anode were investigated in LiF-NaF-KF (FLiNaK, 46.5-11.5-42.0 mol%) eutectic with YF3 at 823 K. Two different types of reactions were observed on graphite anode. The graphite was oxidized to carbon mono- and dioxide in a potential range of 0–2 V (vs. Ni2+/Ni, similarly hereinafter), and carbon fluorides were generated when the potential fell into 6–8 V. In addition, some fluoride products could be reduced at about −0.22 V during reverse cyclic voltammetry scan, which has never been reported. Anode potential fluctuation was found between 6 and 8 V during galvanostatic electrolysis due to the formation of gaseous products as well as change of anode surface area and current density. Both Raman and X-ray photoelectron spectroscopy were employed to probe the chemical states of fluorination/oxidation products on graphite anode after electrolysis. The formation of fluorocarbon species is responsible for the disorder on graphite surface.

High efficient removal and recovery of uranium and thorium from nuclear waste solution are essential for environmental preservation and fuel recycle. A new polymer fiber adsorbent (UHMEPE-g-PAO fiber), prepared by amidoximation of grafted polyacrylonitrile onto Ultra High Molecular Weight Polyethylene (UHMWPE) fiber, was used to remove the uranyl and thorium ions from acid aqueous solutions and its performance was carefully investigated. It was found that uranyl ion can penetrate the fiber through the connected pore structures, forming (UO2) (R-C(NH2)-NO)2 chelates with the amidoxime groups within the fiber. Two amidoxime groups (U-N and U-Oeq) and two water molecules (U-Oeq2) are bound to uranyl ion in the fiber. On the contrary, thorium ions are adsorbed mainly on the fiber surface in the form of Th(OH)4 precipitate that blocks the entrance of Th4+ ion into fiber pores. The maximum included other two capacities of uranyl and thorium ions were estimated to be 262.01 mg/g and 160 mg/g at room temperature with pH 3.0, respectively. The results also indicate that the UHMWPE-g-PAO fiber has higher adsorption selectivity for uranyl ion than thorium ion. Uranium and thorium oxide particles were obtained as the ultimate product after sintering of the fiber adsorbent. This novel and environmentally friendly adsorption process is feasible to extract uranium or thorium from acidic aqueous solution.

Humic substances in the soil and underground water are important media for the environmental fate and transport of oil pollutants, but direct experimental evidence is lacking on the effects of humic acids on the interfacial activity and adsorption properties of oil asphaltenes in the soil. In this study, the oil-water interfacial tension (IFT) was measured by optical contact angle instruments, while the isothermal adsorption of asphaltenes on two montmorillonites and one kaolinite was fitted using four classical models. Results demonstrated that the oil-water IFT decreased by 37.5% when the asphaltenes (500 mg L

Industrial oily wastewater with dye-pollution is a critical environmental issue for water purification. However, the fabrication of effective and stable materials for oil-water separation and simultaneous degradation of organic contaminants remains a critical challenge. Herein, we report a new process for in-situ formation of akaganeite (β-FeOOH) nanorods layer on the surface of poly(ethylene terephthalate) (PET) fabric via radiation-induced graft polymerization of glycidyl methacrylate, which is then sulfonated and mineralized. The resultant product is labeled as β-FeOOH@PET, which exhibits dual purification by demonstrating an effective oil-water separation and organic dyes photodegradation under the illumination of visible light. It provides stable performance even after 1000 wash cycles. The sulfonated layer acts as not only an electronic transport layer to prevent electron-hole recombination, but also as an anchored interface for immobilizing β-FeOOH nanorods on the sulfonated layer via strong covalent bonds. Overall, the superhydrophilicity and underwater superoleophobicity of β-FeOOH@PET fabric, along with its robustness with a flexible organic substrate and its dual purification function, provide a new insight toward oily wastewater remediation and water purification in large-scale applications.

A new type of tunable combined splitter-isolator is proposed in this paper. It is based on the surface magnetic plasmon (MSP) of the chain of ferrite rods. This new type of device mainly consists of two chains of ferrite rods which are under opposite biasing magnetic field. By change the direction of the biasing magnetic field the device can be switched between splitter and combiner. We simulated the power flow and transmission characteristics of the device. The device can realize power splitting function and has good isolation between forward transmission and reverse transmission. The operating frequency band can be tuned by biasing magnetic field, it makes this combined splitter-isolator very flexible in applications. and this type of combined splitter/combiner-isolator can reduce the use of additional isolators and simplify system design in a high-power synthesis application scenario.

Gas hydrate and asphaltene are two major flow assurance issues that will cause severe plugging in the subsea transportation pipelines, but the detailed understanding of their interactions remains insufficient. Systematic experiments were performed in the present study to investigate the influence of light oil components and asphaltene on gas hydrate formation, and to evaluate the performance of commercial kinetic hydrate inhibitors (KHIs) in different oil-water systems. Results demonstrated the promotion effect of light oil on initial hydrate growth, and the inhibition effect of asphaltene particularly with the light oil solvent of toluene. The influence mechanisms of asphaltene were based on the weakening mass transfer of methane at the gas-liquid interface, and the adsorption of free methane in the bulk liquid phase, while the degree of inhibition on hydrate formation was not positively related to the total concentration of asphaltene. Results also indicated that light oil components can weaken the performance of KHIs, but the role of asphaltene was closed related to the type of KHIs and light oil solvent. The overall experimental results of gas hydrate formation in the asphaltene system are consistent with our previous molecular dynamics simulations researches. Meanwhile, it provides an implication that asphaltene may have a potential ability to help some KHIs recover their inhibition performance, and emphasizes the necessity in systematically considering the oil composition when attempting to develop and utilize KHIs in oil-water system.

Polymers with aggregation-induced emission (AIE) characteristics have attracted much attention because of their potential applications in luminescent self-assembling, anti-counterfeiting, decoration, and photoelectric devices. To date, most technologies to prepare fluorescent polymers lack versatility; moreover, the resultant material exhibits intrinsic defects of poor fluorescence intensity and durability. Herein, we covalently anchored units of tetraphenylethylene (TPE), an archetypal AIE luminogen, on the surface of conventional polymer fibers such as polyethylene/polypropylene nonwoven fabric (PE/PP NWF) via radiation-induced graft polymerization (RIGP) and subsequent chemical modification for the first time. The physicochemical properties of the original and modified fabrics were characterized in detail by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), wide-angle X-ray diffraction (WAXD), and thermogravimetric analysis (TGA). The results indicated that the TPE units were covalently and uniformly anchored on the surface of PE/PP NWF with a disordered architecture and that the as-prepared fluorescent fabric had a high thermal stability. Additionally, the fluorescent properties of the as-prepared fluorescent fabric were measured. It emitted a strong green emission and showed superior fluorescence durability after 20 cycles of accelerated laundering or in 12 M concentrated HCl and NaOH solutions.

Global energy issues are becoming increasingly prominent, and have caused widespread attention. Lightweight, thermal insulation, environmentally friendly and recyclable polymeric foam materials exhibit a great application prospects in reducing energy consumption, saving resources and improving utilization. However, there are huge challenges in preparation of such high thermal insulation materials. Herein, recyclable, high mechanical strength and thermal insulation polypropylene (PP) foams were achieved by supercritical CO2 foaming in the presence of β nucleating agent (β-NAs). The obtained PP-β foam exhibited a variety of advantages, including high expansion ratio, continuous honeycomb polygonal cells, a very low thermal conductivity of 26.4 mW/m•K, strong tensile and compressive strength, as well as recyclable property. The accelerated crystallization process, decreased crystal size, and enhanced viscoelasticity caused by the β-NAs contributed to the formation of the multifunctional PP foams. The honeycomb polygonal cells greatly increased the curved path of heat propagation and reduced heat transfer efficiency, as well as enhanced the mechanical properties. Moreover, the compressed PP-β foam still possessed excellent thermal insulation property, as low as 37.1 mW/m•K. The recyclable multifunctional PP foam materials achieved by using physical foaming technology provided a potential solution for the preparation of multifunctional thermal insulation materials, which offered a big application prospect for polymer foam materials in the fields of reducing energy loss.