High-Efficiency Separation of Aromatic Sulfide from Liquid Hydrocarbon Fuel in Conjugated Porous Organic Framework with Polycarbazole Unit

Resistive Memristors Using Robust Electropolymerized Porous Organic Polymer Films as Switchable Materials

Porous organic polymers (POPs) with inherent porosity, tunable pore environment, and semiconductive property are ideally suitable for application in various advanced semiconductor-related devices. However, owing to the lack of processability, POPs are usually prepared in powder forms, which limits their application in advanced devices. Herein, we demonstrate an example of information storage application of POPs with film form prepared by an electrochemical method. The growth process of the electropolymerized films in accordance with the Volmer-Weber model was proposed by observation of atomic force microscopy. Given the mechanism of the electron transfer system, we verified and mainly emphasized the importance of porosity and interfacial properties of porous polymer films for memristor. As expected, the as-fabricated memristors exhibit good performance on low turn-on voltage (0.65 ± 0.10 V), reliable data storage, and high on/off current ratio (104). This work offers inspiration for applying POPs in the form of electropolymerized films in various advanced semiconductor-related devices.

Potential of nonporous adaptive crystals for hydrocarbon separation

Hydrocarbon separation is an important process in the field of petrochemical industry, which provides a variety of raw materials for industrial production and a strong support for the development of national economy. However, traditional separation processes involve huge energy consumption. Adsorptive separation based on nonporous adaptive crystal (NAC) materials is considered as an attractive green alternative to traditional energy-intensive separation technologies due to its advantages of low energy consumption, high chemical and thermal stability, excellent selective adsorption and separation performance, and outstanding recyclability. Considering the exceptional potential of NAC materials for hydrocarbon separation, this review comprehensively summarizes recent advances in various supramolecular host-based NACs. Moreover, the current challenges and future directions are illustrated in detail. It is expected that this review will provide useful and timely references for researchers in this area. Based on a large number of state-of-the-art studies, the review will definitely advance the development of NAC materials for hydrocarbon separation and stimulate more interesting studies in related fields.

Synthesis of Conjugated Mesoporous Hyper-cross-linked Polymers for Efficient Capture of Dibenzothiophene and Iodine

Porous organic polymers have recently received great attention because of their promising applications in the removal of thiophene compounds in liquid fuels and for the nuclear waste (such as radioactive iodine isotopes) treatments. Herein, a series of conjugated mesoporous hyper-cross-linked polymers (CMHPs) were prepared through our newly developed silicon-promoted cationic polymerization in a straightforward manner. The CMHPs exhibited extended π-conjugation, intrinsic porosity, high surface area, and excellent physicochemical stability. They showed an outstanding dibenzothiophene uptake capacity of ∼1335 mg g^-1, which far exceeded many reported porous organic polymers. Meanwhile, these CMHPs showed high adsorption capacity for iodine vapor. Altogether, the CMHPs prepared by the facile and metal-free cationic reactions have great potential in adsorption of harmful substances and environmental protection.

Adsorptive Separation of Aromatic Compounds from Alkanes by π-π Interactions in a Carbazole-Based Conjugated Microporous Polymer

Separation of aromatic/alkane mixtures of similar size and properties is critical for the chemical industry as conventional thermal separation is a high-cost and an energy-intensive process. Adsorptive separation based on porous materials is a prospective and economical technology as well as a suitable alternative to the energy-inefficient heat-driven separation process. With this in mind, we design and synthesize a novel microporous polymer (termed CMP-S-1) with a conjugated aromatic skeleton as a porous adsorbent for aromatic/alkane separation. CMP-S-1 possesses high aromatic adsorption selectivity in two representative separation systems (benzene vs cyclohexane and 3-methylthiophene vs n-octane) based on a vapor adsorption experiment and an ideal adsorbed solution theory simulation. The instant adsorption rate, adsorption energy calculations, and liquid fixed-bed breakthrough experiments give convincing demonstrations on the preferential selective adsorption of aromatic compounds over alkanes in CMP-S-1. The strong π-π interaction between aromatics and the naphthalene ring is considered as the main reason for the strong affinity of aromatic compounds in the CMP-S-1 skeleton. The remarkable aromatic/alkane separation performance of CMP-S-1 verifies the important influence of the π-conjugation interaction in the conjugated porous polymer for the low-energy consumption adsorption separation process.

Design of novel conjugated microporous polymers for efficient adsorptive desulfurization of small aromatic sulfur molecules

This paper presents a computational study of the adsorptive desulfurization of small aromatic sulfur compounds by conjugated microporous polymers (CMPs). The density-functional tight-binding method augmented with an R^-6 dispersion correction is employed to investigate the physisorption binding mechanism and electronic properties of the CMP-aromatic sulfur complexes. We show that the widely extended π conjugation in the CMP skeletons is favorable for the non-covalent adsorption of aromatic thiophene and dibenzothiophene via π-π, H-π, and S-π interactions. The average binding energies are calculated to be -6.2 ∼ -15.2 kcal/mol for CMP- thiophene/dibenzothiophene systems. For the dibenzothiophene molecule with larger size and more extended conjugation, it binds more than twice stronger to CMP than the thiophene molecule. We show that the replacement of quinoline unit to the phenylene group in the network linker effectively enhances the average binding capacities by around 0.8-1.8 kcal/mol. Our calculations theoretically demonstrate that CMPs materials are kind of promising candidates for the adsorptive desulfurization of small aromatic sulfur compounds. This paper provides useful theoretical guidance for design of novel carbon-based adsorbents for adsorptive desulfurization.

Efficient Gold Recovery from E-Waste via a Chelate-Containing Porous Aromatic Framework

Extracting gold from wastes of electronic equipment (e-waste) is a sustainable strategy for the recovery of the precious metal, reducing environmental pollution, and addressing the growing demands for gold resources. In this work, we synthesized a thiourea-modified porous aromatic framework (PAF-1-thiourea) with exceptional gold-extraction ability. The optimum adsorption capacity for PAF-1-thiourea to gold reaches up to 2629.87 mg g^-1. The adsorption process can be well fitted according to the pseudo-second-order kinetic model and Langmuir model, featuring strong affinity caused by strong soft-soft interactions between Au(III) and the S and N donor atoms of the modified PAF and the electrostatic interactions between protonated amino groups and AuCl₄^-. PAF-1-thiourea was especially capable of extracting gold rapidly and efficiently (capturing 98.73% of gold within 5 min) from a central processing unit (CPU) in extremely acidic conditions. It is found that PAF-1-thiourea captures gold ions and simultaneously converts it to a Au(0) solid, obtaining gold with purity up to 23.5 karat. PAF-1-thiourea with its high acid resistance and anti-interference against cheap metals in the recovery process presents a practical means to extract gold from e-waste.

Metal Organic Frameworks as Desulfurization Adsorbents of DBT and 4,6-DMDBT from Fuels

Ultradeep desulfurization of fuels is a method of enormous demand due to the generation of harmful compounds during the burning of sulfur-containing fuels, which are a major source of environmental pollution. Among the various desulfurization methods in application, adsorptive desulfurization (ADS) has low energy demand and is feasible to be employed at ambient conditions without the addition of chemicals. The most crucial factor for ADS application is the selection of the adsorbent, and, currently, a new family of porous materials, metal organic frameworks (MOFs), has proved to be very effective towards this direction. In the current review, applications of MOFs and their functionalized composites for ADS are presented and discussed, as well as the main desulfurization mechanisms reported for the removal of thiophenic compounds by various frameworks. Prospective methods regarding the further improvement of MOF's desulfurization capability are also suggested.