With the booming economy and enhanced quality of life, the problem of a sharp increase in municipal solid waste generation has become increasingly severe. Although waste incineration significantly reduces municipal solid waste volume, it generates hazardous fly ash, whose safe disposal remains a critical challenge. To address this challenge, this study establishes a resource recovery pathway for municipal solid waste incineration fly ash (MSWI-FA) by converting it into high-performance artificial aggregates via disc granulation, followed by targeted physicochemical modification. In concrete production, these aggregates are used as coarse components to produce sustainable artificial aggregate concrete. The results show that the material formulation and granulation process affect the pelletization behavior and the load-carrying capacity of the aggregates. When the mass ratio of cement to MSWI-FA to fly ash in the core phase of artificial aggregate is 3.6:6.4:1, and the mass ratio of cement to slag in the shell phase is 3:7, the performance of the artificial aggregate is optimal. Specifically, the optimized aggregate has a bulk density of 1850 kg/m3, a 24-hour water absorption rate of 8.3 %, and a 28-day cylinder compressive strength of 7.38 MPa. Modification with an activator significantly enhances its performance relative to conventional aggregates: when using 6 % liquid Na2SO4 as the activator, the maximum compressive strength reaches 8.57 MPa, representing an approximate 20 % increase compared to the blank group. Additionally, the incorporation of 5 % inorganic silicon as a water repellent yields a softening coefficient of 0.84, indicating improved water resistance. This study provides a potential approach to effectively alleviate the pressure from the accumulation of MSWI-FA, fly ash, and slag, as well as the shortage of natural aggregates in China.

Metal centralizers suffer high frictional resistance, high self-weight, and severe pore shrinkage after perforation in deep, highly deviated, and horizontal wells. Targeting the performance demands of adhesive casing centralizers, this study uses epoxy resin as the matrix, introduces amino modification, and regulates inorganic filler composites to prepare an amino-modified epoxy resin composite centralizer material, followed by systematic property tests. The optimal formula of modified epoxy resin:curing agent:UR300 accelerator:amino-modified silica:silicon carbide:alumina is 100:10:1:1:35:20 and delivers superior comprehensive performance. Its compressive strength reaches 136.61 MPa with a Shore hardness of 92.32 HD, low linear expansion, and favorable thermal compatibility with steel casings. Hardness remains stable after 168 h of aging at 150 °C, and the material maintains low friction at ambient and elevated temperatures. After 30-day immersion in acidic, alkaline, and high-salinity fluids, its compressive strength retention exceeds 86% with a slight variation in volume and mass, while adhesion strength reaches 2.667 MPa at a pipe-wall roughness of 12.12 μm. Combining high strength, heat resistance, corrosion resistance, and strong adhesion, the material suits complex downhole conditions and supports the field application of resin composite centralizers.

Nature-inspired strategies dominate the current marine green antifouling; nevertheless, a single biomimetic antifouling strategy has limitations in a static or dynamic marine environment. Inspired by fluorescent corals and squids, this study integrated CsPbX3/CsPbBr3 (X = Cl or I) perovskite homojunctions with fluorescent and photocatalytic properties into low-surface-energy hydration-containing polyurethane. This establishes a synergistic biomimetic antifouling mechanism utilizing fluorescence catalysis and a low surface energy hydration layer while further exploring the regulatory principles of antifouling performance using different colored fluorescence. The presence of low surface energy facilitates the separation and transfer of homojunction charge, while the formation of a hydrated layer and homojunction significantly enhances the release of reactive oxygen species, with •O2- and 1O2 free radicals playing a crucial role. In addition, the coating can fluoresce in nine colors, with blue-green fluorescence exhibiting the most effective antifouling properties. This is attributed to the higher photon energy of blue light, which stimulates the photosensitive substances within bacteria to generate reactive oxygen species, damaging the cell membranes and DNA of the biofouling and thereby achieving an antifouling effect. This research thus provides a promising pathway for the development of highly efficient marine fluorescent antifouling coatings.

ABSTRACT Band pressure operation has become the main way of oil and gas well workover in the world, to solve the gel breaking problem in the gel plugging pressure technology, acrylamide and ester‐based cross‐linking agent UCL‐1 were used to synthesize a self‐degradable gel that can be used at 40°C–60°C by the one‐pot method. The cross‐linking reaction principle of the gel was analyzed by infrared spectroscopy; in addition, the degradation performance of the gel and the effects of acrylamide, UCL‐1, initiator and metal ions on the degradation performance of the gel as well as the influence law were investigated; finally, sand‐filled tubing and casing were used to simulate the stratigraphy and the wellbore, respectively, thus evaluating the sealing performance of the gel. The results showed that the cross‐linking reaction of the gel was a double‐bond copolymerization reaction; the viscosity of the gel after complete degradation in the range of 40°C–60°C was 51–450 mPa‐s, and the degradation time was 115–220 h, and the degradation time of the gel could be adjusted by changing the formulation components and the mineralization degree; moreover, the pressure‐bearing capacity of the gel in the formation at 40°C–60°C was 8.5–14.9 MPa, and the pressure‐bearing capacity of gel in wellbore is 52–73 kPa, and the blocking time is 3–6 d, which meets the construction time requirement of pressurized operation. This study extends the breaking method of gel plugging pressure technology and further promotes the development and application of pressure work technology.

Addition of melamine formaldehyde (MF) as a crosslinker containing hydroxymethyl to partially hydrolyzed poly(acrylamide) (HPAM) generated covalently crosslinked in situ gels through chemically nucleophilic attack by hydroxymethyl groups to amide in an HPAM backbone, which was demonstrated by FTIR spectrum analysis and rheological studies. NH4Cl could act as a catalyst to reduce the gelation time from 7 days in dilute water to 8 h in the presence of 0.8 wt % NH4Cl. Compared to high-temperature HPAM/phenol/formaldehyde and HPAM/Cr3+ gel systems, this gel has better adhesion and higher strength over a broad range of temperature from 60 to 100 °C under reservoir conditions with a denser and hook-like three-dimensional microstructure. Pressure-bearing capacity experiments demonstrated that the gel could efficiently plug high pressure from underneath to seal the wellbore, attributing to its high strength and good adhesion. This study could aid petroleum engineers in applying soft materials on controlling the pressure via polymer gels.

Conventional preformed particle gels suffer from insufficient salt tolerance and weak mechanical properties after water absorption, which reduce the water shutoff effect in mature oilfields. In this paper, a nanocomposite particle gel (NCPG) is synthesized by copolymerization of acrylamide (AM) and 2-acrylamido-2-methylpropane sulfonic acid (AMPS) using laponite RD (LPT) as a physical cross-linker and N,N-methylene-bisacrylamide (MBA) as a chemical cross-linker via in situ free radical polymerization. Compared with the NCPG without LPT, both the swelling rate and mechanical properties of NCPG added with LPT are found to be improved. In addition, the pore sizes of the network of the swollen NCPG are smaller than those of the sample without LPT, and the thermal stability is also slightly enhanced. The swelling rate of NCPG increases with increasing AMPS concentration. The water absorbency of NCPG first increases and then decreases with increasing MBA and APS concentrations. The NCPG is sensitive to alkaline medium due to the presence of sulfonic acid groups on the molecular chains of the NCPG. The synthesized NCPG exhibits good salt tolerance at 80 °C in formation water. The plugging rate of the NCPG to a sand-pack is above 90%, and the residual resistance factor reaches 19.2 under reservoir conditions. These results indicate that the NCPG may have potential application for water shutoff treatment in mature oilfields.

Integrating multiple mechanisms to maximize photothermal conversion efficiency is a significant strategy but remains challenging to construct therapeutic agents toward photothermal tumor treatment. Here, an approach to synthesize asymmetric Bi 2 Se 3 /CdSe‐Au hierarchical nanorods with excellent photothermal conversion is reported. Ag wetting‐layer is firstly grown to help overcome the interfacial lattice mismatch and promote the site‐selective growth of AgCdSe onto one end or side surface of Au nanorods. Subsequently, extraction of Ag + ions out of lattice is observed during cation exchange reaction and epitaxial growth of Bi 2 Se 3 shell. Bi 2 Se 3 /CdSe heterojunction with type‐II band alignment is formed and located at the plasmonic hotspots of Au nanorods, which experiences enhanced light absorption and accelerates the charge separation of photo‐excited carriers. Under excitation of near‐infrared 808 nm laser, the matchstick‐like Bi 2 Se 3 /CdSe‐Au nanorods show an excellent photothermal conversion, with 4.3 times temperature increment ( Δ T ) than that of bare Au nanorods. Moreover, in vitro and in vivo experiments verify them as excellent photothermal therapeutic agents.

During underbalance drilling, completion and workover wells, plugging channeling, blocking preformation and plugging formation water are inevitable problems. Gel is one of the most effective and convenient method to solve the problem. In this study, modified starch gel is synthesized, investigated experimentally and improved for efficient oil and gas field applications. The gel slurry is composed of starch (3.6 wt.%), initiator (0.02 wt.%), acrylamide (14.4 wt.%), cross-linking agent (4.7 wt.%), all of the components are mixed together with water at pH 10 – 11 which viscosity is as low as 35 – 82 mPa.s and desired to form gel. Here the effects of the components, reaction temperature and pH on gelation time and gel viscosity are systematically investigated, and the results showed that the gelation can be controlled in a wide range 30 – 120 min efficiently by pH and initiator. Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM) are employed to study the molecular structure and microstructure of the gel, respectively. A compact three-dimensional network structure was formed in the gel, which contribute to a good adhesion. The gel has been successfully used in shale gas field which provides a reference for sealing other similar high formation pressure under unbalanced workover treatment. DOI: http://dx.doi.org/10.5755/j01.ms.24.4.18565

The gelation process of organically polymer gel was investigated by dynamic thickening measurements. Rheological measurements were used to evaluate the viscosity of the gel. During the gelation process, high temperature resulted in higher rate of crosslinking. Rigid and stable gel was formed in neutral and alkaline media, and the higher of the pH value, the faster of the gelation process. However, gel could not be formed in acid condition. Moreover, the rate of crosslinking increased with the increase of concentration of polymer and crosslinker. The addition of NH4Cl elongated the gelation time significantly, but played a negative role in the gel strength, while a rigid gel was formed in the presence of Sodium acetate or trisodium citrate dehydrate. This paper summarizes the results and discusses how various parameters affect the gelation process of the gel.

The incorporation of quantum dots (QDs) into chalcogenide glass films is attractive for their luminescent properties. Such QD-doped glass structures could serve as a compact, on-chip light source for planar photonic devices. Typical processing methods such as spin coating have limitations of excessive material waste, little control on the pattern of the film and difficulty for scale-up. To overcome these limitations, this study introduces electrospray as a more versatile processing method and has deposited QD-doped chalcogenide glass thin films. The parameters of the electrospray process are prudently chosen to ensure one or none QD is enclosed per liquid droplet. The transmission electron microscopy imaging of resultant films confirm enhanced QD dispersion with reduced aggregations. Absorption and photoluminescence characterization shows the QD-doped chalcogenide glass films prepared by electrospray maintain signature spectra of QDs from the manufacturer.

A chromium gel formed through the cross-linking reaction with partially hydrolyzed polyacrylamide and Cr3+, known as Cr3+ gel, has been demonstrated to use in petroleum engineering for its special mechanical properties in this paper. This study has revealed that the addition of cellulose can successfully enhance the gas sealing ability of a gel slug in a wellbore. Scanning electron microscopy was employed to understand the cross-linked structure of the Cr3+ gel. Furthermore, the mechanical properties were studied, revealing that the maximum tensile strain increased from 2.07 to 3.45 with shear strains increasing from 1.32 to 1.45. Additionally, the cementing strength of modified gel characterized by the maximum pull-out force decreased from 13.1 to 7.2 N. The pull-out force changed smoothly with the displacement due to the viscous resistance increased. In this study, a systemic test method for the mechanical properties of Cr3+ gel was proposed, and the roles of cellulose in enhancing the toughness and viscosity of gel were attained.

Novel pH sensitive Di-CnPh gemini amphiphiles can act as both the phase-transfer reagent and stabilizer to make extremely small Au nanoparticles.

With fault of partial overheating, trace O_2 participates in SF6 decomposition process directly. When SF6 characteristic components are used to diagnose thermal fault of SF6 gas-insulated equipment, we must take the effect of trace O_2 into account. Therefore, a series of thermal decomposition experiments through controlling the content of trace O_2 in pure SF6 were conducted on the existing simulation system. Influences of trace O_2 on the formation of the main characteristic components of SF6 thermal decomposition were achieved. It is found that the SOF4 and SO_2F2 increase with the increase of O_2. SOF4 can be converted into SO_2F2 and trace O_2, which increase the products SO_2F2 exponentially with trace O_2. The reaction between trace O_2 and primary products of SF6 thermal decomposition makes SO_2 to be the major product. However, the F atoms and O atoms compete the intermediate decomposition products, which ensure SO_2 to reach saturation, and the absolute yield of SOF2 first increases and then decreases. The results show that the characteristic components of SF6 thermal decomposition are influenced by trace O_2 specially for SO_2F2, and the products SO_2 and SO_2F2 are found to be main components.

Li 2 O-Al 2 O 3 -SiO 2 glass-ceramics doped with Nd 2 O 3 were prepared by the melting method. The effects of Nd 2 O 3 on the crystallization behavior of Li 2 O-Al 2 O 3 -SiO 2 glass-ceramics were studied by DTA, XRD and SEM. With the increase of Nd 2 O 3 content, the glass crystallization temperature arised. The SEM result indicates that the main crystal phase of Li 2 O-Al 2 O 3 -SiO 2 glass-ceramics doped with Nd 2 O 3 is β-quartz solid solution, for without doping Nd 2 O 3 it is β-spodumene solid solution. These results shows that the crystallization temperature increases significantly by doping Nd 2 O 3 , and phase transition from β-quartz to β-spodumene is suppressed. The grain size increases with the increase of Nd 2 O 3 content.

Li2O-Al2O3-SiO2 glass-ceramics doped with Nd2O3 were prepared by the melting method. The effects of Nd2O3 on the crystallization behavior of Li2O-Al2O3-SiO2 glass-ceramics were studied by DTA, XRD and SEM. With the increase of Nd2O3 content, the glass crystallization temperature arised. The SEM result indicates that the main crystal phase of Li2O-Al2O3-SiO2 glass-ceramics doped with Nd2O3 is β-quartz solid solution, for without doping Nd2O3 it is β-spodumene solid solution. These results shows that the crystallization temperature increases significantly by doping Nd2O3, and phase transition from β-quartz to β-spodumene is suppressed. The grain size increases with the increase of Nd2O3 content.

A series of novel pH sensitive Gemini amphiphiles of N,N'-dialkyl-N,N'-di(ethyl-phthalimide) ethylenediamines (Di-CnPh, n=6, 8, 10, 12) was synthesized and characterized. It was found that relatively stable spread monolayers of Di-CnPh can be formed at the air/water interface once n≥6, and their stability was improved by increasing the hydrophobic chain length or adding electrolyte. The surface pressure-area (π-A) isotherms of Di-CnPh have been studied in detail by employing the axisymmetric drop shape analysis as penetration Langmuir balance. Furthermore, Brewster angle microscopy (BAM) was employed to confirm the monolayer phase transition from gaseous phase to liquid condensed phase via a liquid expanded phase. Moreover, dilatational rheological measurements of spread Di-CnPh monolayers at the air/water interface were performed, and the influence of the hydrophobic chain length and pH on the dilatational elasticity (ε) and viscosity (η) was also investigated. The results have suggested that the spread Di-CnPh monolayers are spontaneously elastic.

A new family of gemini surfactants with pyrrolidinium head groups, 1,1′-(alkane-1, s-diyl)bis(1-dodecyl pyrrolidinium)bromide (C12–Cs–C12PB, s = 3, 4, 6, 8, 10, 12, 14, and 16), were synthesized. Their adsorption and micellization in aqueous solutions were investigated by various techniques such as equilibrium surface tension, fluorescence, and conductivity in detail. It was found that the effect of the spacer length on surfactant aggregation in aqueous solutions is similar to that of the well-known gemini surfactants with quaternary ammonium head groups (m-s-m), whereas the occupied limiting area per molecule (Amin) at the surface increases linearly with s rather than going through a maximum value at a medium value of s like that of m-s-m. The thermodynamic parameters suggest that the micellization of C12–Cs–C12PB is an entropy driven process regardless of the spacer length s. Moreover, a second breakpoint appeared in both γ–log c and I1/I3–c curves of C12–C14–C12PB and C12–C16–C12PB as the surfactant concentration increases, which can be attributed to the formation of larger aggregates. The morphology of the aggregates is confirmed by employing dynamic light scattering (DLS) and cryo-transmission electron microscopy (cryo-TEM) techniques.

A series of pH sensitive single-tailed surfactants, N-alkyl-1,2-ethylenediamine (CmN2N, where m = 8, 10, 12, 14, 16), were synthesized and characterized. The adsorption and aggregation properties of them were determined by equilibrium surface tension, static and dynamic light scattering (SLS and DLS), rheology, and cryogenic transmission electron microscopy (cryo-TEM) techniques in detail. It was found that both the surface activity and self-assembly behavior of CmN2N were strongly dependent on the solution pH, owing to the protonation state of amino groups in CmN2N. When at least one of the amino groups of CmN2N was protonated the logarithm of the critical micelle concentration (cmc) followed the well-known Klevens equation, i.e. cmc decreased linearly with the increase of hydrocarbon chain length. Simultaneously, the surface adsorption area per molecule (Amin) was decreased for each CmN2N when the solution pH varied from acidic to basic conditions. The pH-dependent micelle to vesicle transition was universally observed in the bulk phase of CmN2N. More interestingly, the rodlike micelles formed in C10N2N, C12N2N and C14N2N could transform into vesicles reversibly upon heating or cooling, which indicated the thermal sensitivityof organized assemblies, whereas not in C8N2N and C16N2N.

A new series of pH-responsive Gemini surfactants with 2-pyrrolidone head groups, N,N'-dialkyl-N,N'-di(ethyl-2-pyrrolidone)ethylenediamine (Di-C(n)P, where n = 6, 8 10, 12), were synthesized and characterized by (1)H NMR, (13)C NMR, ESI-MS, and elemental analysis. The surface activity and micellization behavior at acidic, neutral, and basic conditions were characterized by equilibrium surface tension and fluorescence techniques. It was found that the surface activity of Di-C(n)P depends on the pH of aqueous solutions due to the protonation state of surfactant molecules when pH was varied. The new compounds have lower cmc and γ(cmc) in comparison with that of m-2-m type conventional cationic Gemini surfactants and gluconamide-type nonionic Gemini surfactants. Fluorescence data confirm that micelles are formed when the concentration is above the cmc. Since micellization is of fundamental importance in surfactant applications such as solubilization, microemulsion, and related technologies, the significant difference in cmc at different pH of this new Gemini surfactant is employed to solubilize cyclohexane. The preliminary result indeed shows that the solubilization capacity of Di-C(n)P can be tuned by pH.

Radiation with UV-B increased the damage to DNA in Scytonema javanicum, a desert-dwelling soil microorganism, and the level of damage varied with the intensity of UV-B radiation and duration of exposure. Production of reactive oxygen species (ROS) also increased because of the radiation. Different exogenous chemicals (ascorbate acid, ASC; N-acetylcysteine, NAC; glyphosate, GPS; and 2-methyl-4-chlorophenoxyacetic acid, MCPA-Na) differed in their effect on the extent of DNA damage and ROS production: whereas NAC and ASC protected the DNA from damage and resulted in reduced ROS production, the herbicides (GPS and MCPA-Na) increased the extent of damage, lowered the rate of photosynthesis, and differed in their effect on ROS production. The chemicals probably have different mechanisms to exercise their effects: NAC and ASC probably function as antioxidant agents or as precursors of other antioxidant molecules that protect the DNA and photosynthetic apparatus directly from the ROS produced as a result of UV-B radiation, and GPS and MCPA-Na probably disrupt the normal metabolism in S. javanicum to induce the leaking of ROS into the photosynthetic electron transfer pathway following UV-B radiation, and thereby damage the DNA. Such mechanisms have serious implications for the use of environment-friendly herbicides, which, because they can destroy DNA, may prove harmful to soil microorganisms.