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Plastic waste and debris have caused substantial environmental pollution globally. In this work, a new engineering concept of the mobile recycling platform for plastic waste is proposed. And a four-column distillation scheme for separating plastic pyrolysis oil was built for the mobile recycling platform. Firstly, a VOF CFD simulation was conducted to reveal the liquid flow characteristics along and inside the θ-ring, and then based on the CFD data and theoretical analysis, an optimization model for the packing ring was proposed to design the wavy ring. Secondly, the novel wavy rings were applied in the four-column distillation experiment, and acetophenone (99.68w%) and phenol (98.94w%) were separated from the pyrolysis oil. Finally, the heat integration of the four-column distillation scheme and the engineering economic analysis of the mobile recycling platform were carried out. The results indicate that the mobile recycling platform is feasible in terms of theory, technology, and economics.

Distillation is the most common separation technology utilized in the petroleum and chemistry industries. Due to the wide usage of the distillation column, even a small improvement in performance may result in significant energy cost savings. Aiming to improve the hydrodynamics and mass transfer performance, the flow-guided trapezoid spray-packing tray (FTS-PT) was designed by combining flow-guided holes and trapezoidal caps with structured packing. And the experimental measurements of the FTS-PT, including pressure drop, clear liquid height, weeping, entrainment, and tray efficiency, were conducted in a 500 mm diameter plexiglass column with the air-water-oxygen system. Moreover, the performance of the FTS-PT was compared with that of New VST and F1 valve tray. The results show that FTS-PT has a significant advantage in pressure drop, entrainment, and capacity. Furthermore, the calculation model of the pressure drop was derived and used for the FTS-PT with a relative deviation of less than 5%.

As there is an azeotropic point between methanol and ethyl formate, they cannot be completely separated by ordinary distillation. In this paper, extractive distillation was applied and dimethyl sul...

Band-gap engineering of molybdenum disulfide (MoS2) by introducing vacancies is of particular interest owing to the potential optoelectronic applications. In this work, systematic density functional theory (DFT) calculations were carried out for few-layered 3R-MoS2 with different concentrations of S vacancies. All results revealed that the defect energy levels introduced on both sides of the Fermi level formed an intermediate band in the band gap. Both the edges of the intrinsic and intermediate bands of the structures with the same type of vacancies were generally closer to the Fermi level, and the gaps decreased as the number of layers increased from 2 to 4. The preferentially formed S vacancies at the top layer and the transition of defect types from point to line led to similar indirect band gaps for 2- and 4-layered 3R-MoS2 with a low bulk concentration (around 5%) of S vacancies. This is different from most reported results about transition metal dichalcogenide (TMD) materials that the indirect band gap decreases as the number of layers increases and the low concentrations of vacancies show negligible influence on the band gap value.

The formation of heterogeneous ternary azeotropes poses a serious challenge to the recovery of diisopropyl ether (DIPE) and isopropyl alcohol (IPA) from the industrial effluent. To reduce the energ...

In this work, ionic liquid (IL) as green solvent was first proposed for capturing methanol and dimethoxymethane (DMM) gases released in the fuel synthesis process. The hydrophilic IL [EMIM][BF4] was selected from 192 kinds of ILs by the COSMO-RS model. The separation mechanism was revealed at the molecule level in combination with the quantum chemistry calculation. The vapor-liquid equilibrium (VLE) data for the binary mixture of methanol (or DMM) and [EMIM][BF4] were experimentally obtained and compared with the prediction of UNIFAC-Lei model. It was found that the popular UNIFAC-Lei model can predict the VLE of the methanol + [EMIM][BF4] and DMM + [EMIM][BF4] mixtures well. Moreover, the methanol and DMM capture experiments using [EMIM][BF4] as absorbent were carried out, demonstrating the good separation performance. Furthermore, a rigorous equilibrium EQ stage model including the UNIFAC-Lei model parameters was built for simulating and optimizing the methanol and DMM capture processes using [EMIM][BF4] and the conventional benchmark solvent triethylene glycol (TEG) as absorbents at industry level. This work confirmed that capturing methanol and DMM gases with ILs is a typical process intensification method.

Column setup has been widely utilized in the petroleum and chemistry industries. However, with the fast progress of industries and the increasingly serious energy shortage, designing a new column setup with better performance and higher capacity becomes more urgent. In order to improve column's capacity and expand operating condition, a new type of column tray named novel vertical spray packing (NVSP) tray was designed and experimented. The performances of the novel tray, including pressure drop, weeping, entrainment and tray efficiency, were tested in a plexiglass column. In addition, performances of the novel tray were compared with that of the sieve tray and the Glitsch V1 valve tray. Based on the experiment data, the mathematical correlations of pressure drop, weeping and entrainment for the novel tray were established by regression analysis method. A fundamental model of dry pressure drop of the novel tray was promoted at the form of sum mode. The results indicate that the novel tray has wider operating condition and better performance.

In order to achieve higher throughput and better tray efficiency, this paper proposed a new type of flow-guided vertical packing tray, referred to as Novel FVPT, according to the design idea of composition. The novel tray was subjected to a cold mode experiment using an air-water (oxygen-enriched water) system in a 500 mm diameter Plexiglas column. The experiment included the clear liquid height, the dry pressure drop, the total pressure drop, entrainment, weeping and mass transfer efficiency. The correlation of the performance of the novel tray with the two-phase loading was invested in this work. Based on the mechanism of the pressure drop, the fundamental model of dry pressure drop of the novel tray was proposed. In addition, the industrial application of the novel tray was illustrated. The results showed that the novel tray with high throughout and better tray efficiency brought great economic and environmental benefits.

ZnO films codoped by copper and nitrogen were prepared by magnetron cosputtering. The effects of this codoping on the structural and optical properties of ZnO films were systematically studied. The results show that Cu–N codoping didn’t affect the optimal orientation. Cu–N codoping can enlarge the grain size, enhance the crystallinity, reduce the stress and lead to denser and smoother surface. A significant red shift of absorption edge and gap-narrowing effect resulting from codoping were found in ZnO films. Cu-doping, N-doping, and oxygen vacancy are the main factors leading to property modification of the ZnO films. By Cu–N codoping, we can modulate the microstructure and optical properties of ZnO films in a wider range.

The epidermal growth factor receptor (EGFR) has become an important target protein in anticancer drug development. Meanwhile, peptide-Au cluster has been proposed as potential targeted nano-drug assembled by targeting peptide. Here, we designed and synthesized a novel peptide-Au cluster as Au10Peptide5 to target to EGFR. We found Au10Peptide5 could target to the natural binding sites of all EGFRs at membrane in both active and inactive states by molecular simulations. Its targeted ability was further verified by the co-localization and blocking experiments. We also study the configuration modifications of both active and inactive EGFRs after binding by Au10Peptide5. For active EGFR, the absorbed Au10Peptide5 might replace the natural ligand in EGFR endocytosis process. Then, the peptide-Au cluster in endochylema could inhibit the cancer relating enzyme activity including thioredoxin reductase1 (TrxR1) and induce the oxidative stress mediated apoptosis in tumor cells. For inactive EGFR, it was retained in inactive state by Au10Peptide5 binding to inhibit dimerization of EGFR for anticancer. Both pathways might be applied in anticancer drug development based on the theoretical and experimental study here.

The atomic structures and the corresponding physicochemical properties of peptide coated Au nanoclusters determine their distinctive biological targeting applications. To learn the modulation of amino acid ligand on the atomic structure and electronic characteristics of coated Au core is the fundamental knowledge for peptide coated Au nanocluster design and construction. Based on our recent coated Au nanocluster configuration study (Nanoscale, 2016, 8, 11454), we built the typically simplified Au13(Cys-Au-Cys) system to more clearly learn the basic modulation information of amino acid ligand on Au core by the density functional theory (DFT) calculations. There are two isomers as ligand adjacent bonding (Iso1) and diagonal bonding (Iso2) to Au13 cores. The geometry optimizations indicate the adjacent bonding Iso1 is more stable than Iso2. More important, the Au13 core of Iso1 distorts much more significantly than that of Iso2 by Cys-Au-Cys bonding through the root-mean-square deviation (RMSD) analysis, which modulate their electronic characteristics in different ways. In addition, the frontier molecular orbital results of Au13(Cys-Au-Cys) isomers confirm that the Au cores mainly determine the blue shifts of Au13(Cys-Au-Cys) systems versus the original Au13 core in their UV-visible absorption spectrum studies. The configuration of Au13 core performs deformation under Cys-Au-Cys ligand modulation to reach new stability with distinct atomic structure and electronic properties, which could be the theory basis for peptide coated AuNCs design and construction.

In this work, the sieve-fixed valve (SFV) tray was designed by adding flow-guiding and sieve holes on the valve caps of the original trapezoid valve (OTV). A computational fluid dynamics (CFD) model of three-dimensional two-phase flow was developed to describe the flow structure of SFV tray. Based on the experimental clear liquid height, the modified correlation of Bennett was adopted for liquid–gas interaction and the ga–liquid momentum transfer term MGL was also obtained. To demonstrate the function of flow-guiding hole and sieve hole, the hydrodynamics of the OTV and SFV trays including pressure drop, weeping, entrainment and clear liquid height were experimented and compared. What’s more, local information such as velocity profile and flow field around the valves were simulated. CFD results showed that the new valve tray with flow-guiding holes was capable of promoting liquid flow and homogenizing liquid flow. This study proved that CFD research can test modification of devices, and provide information which could not be obtained by experiment. The CFD method tends to be a necessary part for designing and modifying new distillation internals.

Band-gap engineering of molybdenum disulfide (MoS

PbI2/MoS2, as a typical van der Waals (vdW) heterostructure, has attracted intensive attention owing to its remarkable electronic and optoelectronic properties. In this work, the effect of defects on the electronic structures of a PbI2/MoS2 heterointerface has been systematically investigated. The manner in which the defects modulate the band structure of PbI2/MoS2, including the band gap, band edge, band alignment, and defect energy-level density within the band gap is discussed herein. It is shown that sulfur defects tune the band gaps, iodine defects shift the positions of the band edge and Fermi level, and lead defects realize the conversions between the straddling-gap band alignment and valence-band-aligned gap, thus enhancing the light-absorption ability of the material.

In this study, a novel type of structured wire gauze packing was designed, investigated, and compared with initial packings to improve hydrodynamic performances. The results of the comparison indicated that the novel packing exhibits superior performances, especially in reducing the wall flow phenomenon and lowering pressure drop. Furthermore, a new multi-scale computational fluid dynamics (CFD) method was proposed for the first time to calculate the wet pressure drop of the structured wire gauze packing. A three-dimensional VOF CFD method was established at a small scale to simulate the liquid film on a wire gauze to obtain an appropriate liquid feeding rate and contact angle. Subsequently, based on a small-scale simulation, the effective wet area was calculated at mesoscale simulation. The wet area is an important parameter for building the mechanistic wet pressure drop model. Finally, the novel packing and the mechanistic model were successfully applied in a restructuring project to validate their accuracy and reliability.

To recover diisopropyl ether (DIPE) and isopropyl alcohol (IPA) from industrial wastewater through extractive distillation (ED), the most suitable extrainer 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]) was screened out by comparing the selectivity of DIPE to IPA and IPA to water in ionic liquids (ILs) composed of 9 common cations and 12 common anions. Theoretical insight at the molecular level based on surface charge-density (σ-profiles) and excess enthalpy (HE) was provided to analyze the hydrogen bonding and separation mechanism between IL and the azeotrope. Isobaric vapor-liquid equilibrium (VLE) experiment of DIPE + IPA + [EMIM][OAc] and IPA + water + [EMIM][OAc] further validated the predicted results. After inputting the binary interaction parameters, the ternary ED configuration with [EMIM][OAc] as entrainer was simulated, and the thermal integration scheme was further explored. Comprehensive evaluation demonstrated that when compared to ethylene glycol (EG), the energy-integrated ED scheme with [EMIM][OAc] as entrainer saves energy consumption and the total annual cost (TAC) of 27.71% and 12.29%, respectively. This separation method provides a more energy-efficient and environmentally friendly choice for clean production of IPA.

Undoped and Cu-doped zinc oxide (ZnO:Cu) films were deposited on glass substrates by magnetron sputtering at different oxygen partial pressures po. Microstructure, surface morphology, resistivity, and optical properties were systematically investigated. The results show that lower po can degrade the crystallinity, and reduce the band gap. Undoped ZnO films are not obviously influenced by po, especially at high oxygen pressure. In contrast, ZnO:Cu thin films are remarkably affected by po. This work suggests that oxygen vacancies play an important role in modifying properties and allows us to accurately modulate the band gap of the ZnO-based films.

Environmental problems caused by the development of nanotechnology have threatened human health. Investigating the biomedical effects of nanomaterials can help to solve these environmental safety issues. In studies on the biomedical effects of nanomaterials, several types of novel nanoscale probes that allow reliable, sensitive, accurate and rapid biomedical detection have emerged. We summarize recent developments in three categories of these nanoprobes, including noble metal nanocluster probes, carbon-based nanostructured probes, and unnatural amino acid-based probes. Besides reviewing the utility of different nanoprobes in cell imaging and protein detection, we also discuss the molecular mechanism of nanoprobe detection. Perspectives of novel nanoprobe design based on molecular details of biomedical detection are presented.

ZnO-based resistive switching device Ag/ZnO/TiN, and its modified structure Ag/ZnO/Zn/ZnO/TiN and Ag/graphene/ZnO/TiN, were prepared. The effects of inserted Zn layers in ZnO matrix and an interface graphene layer on resistive switching characteristics were studied. It is found that metal ions, oxygen vacancies, and interface are involved in the RS process. A thin inserted Zn layer can increase the resistance of HRS and enhance the resistance ratio. A graphene interface layer between ZnO layer and top electrode can block the carrier transport and enhance the resistance ratio to several times. The results suggest feasible routes to tailor the resistive switching performance of ZnO-based structure.