To obtain solid scaffolds exhibiting brilliant solid state fluorescence and serving as an arena for chromo communication via host–guest energy transfer, a series of diketopyrrolopyrrole moieties with different modified bulky groups were coupled into the porous polymeric networks via Sonogashira coupling reaction. Variation of the bulky substitution groups rendered the tunability of porosity. With the improved porosity, it triggered the spatial isolation of the fluorophores and further enhanced the solid-state fluorescence of these polymers. More importantly, the brilliant nanopores can also serve to confine guest molecules to form a donor–acceptor system via energy transfer. After loading coumarin, outstanding energy transfer efficiency, was observed based on the calculation upon fluorescence decay measurements, spectral overlap function and the estimation of Föster radius. This study provided important insights of designing novel fluorescent POPs with efficient energy transfer flows.

We proposed an in situ interfacial growth method induced by the Pickering emulsion strategy to produce metal organic framework (MOF)/graphite oxide (GO) composites of Cu3(BTC)2/GO, in which GO was demonstrated to be a promising stabilizer for producing the Pickering emulsion and provided a large interfacial area for the in situ growth of Cu3(BTC)2 nanoparticles. When Cu3(BTC)2/GO composites were used as adsorbents for CO2 capture from the simulated humid flue gas, they showed both significantly improved thermodynamic and dynamic properties. Because most of the H2O molecules were adsorbed on the highly exfoliated GO sheets in Cu3(BTC)2/GO-m, CO2 uptake reached 3.30 mmol/g after exposure to the simulated flue gas for 60 min and remained unchanged for up to 120 min. This highlighted its potential application for real CO2 capture. More importantly, the in situ interfacial growth of nanoparticles induced by Pickering emulsions would be a promising strategy for designing and fabricating nanocomposites.

Porous poly(ionic liquids) (PPILs) with both advantages of ionic liquids (ILs) activities and porous properties have caused great interests in adsorptive desulfurization. High density of active functional groups and large surface area in PPILs are two critical factors for enhancing the desulfurization performance; however, there is usually a trade-off between them. In this work, a novel PPIL of poly(bipropargyl-imidazolium chloride) (P[BPPIM]) was fabricated through a single-step cyclotrimerization homopolymerization. Through this full-atomic utilization method, the mass density of active imidazolium groups were maximized; meanwhile, the introduction of rigid benzene rings within imidazolium rings propped up the porous structure in P[BPPIM], with a surface area of 160.8 m2·g–1 and pore volume of 0.39 cm3·g–1. On the basis of the density function theory calculation, the binding energies of dibenzothiophene (DBT) over P[BPPIM] were significantly increased due to the synergistic effect of the imidazolium ring and benzene ring, resulting in an enhanced saturated DBT adsorption capacity of 37.13 mgS·g–1, which was the best one among all the reported PILs according to our knowledge.

•A pilot trial for desulfurization by simultaneous adsorption-separation is proposed.•Fast adsorption of MOF-199 is comparable to separation efficiency of hydrocyclones.•A convenient oxidation method to regenerate MOF-199 adsorbent is explored.•Ultra-fast desulfurization is realized by decreasing 50 ppm DBT to 8.79 within 30 s.•The separation efficiency of MOF-199 particles is as high as 99.75%.Deep removal of organic sulfur from fuel has become an important issue worldwide in the field of energy and environment. In this work, a novel approach for efficient adsorption-desulfurization in which both the adsorption and separation processes were performed simultaneously was demonstrated in a two-stage hydrocyclones pilot trial. We applied mass-produced MOF-199 as the adsorbent and dibenzothiophene (DBT) dissolved in dodecane as the model fuel. The adsorption dynamics and the significant influences of the dosage of adsorbent, the inlet flow rate and the split ratio on the removal efficiency were investigated to match the simultaneous adsorption-separation processes. After optimizing the operating conditions, the ultimate DBT concentration in the outlet of the two-stage hydrocyclones was 8.79 ppmw, which was less than the regulatory target of 10 ppmw; the separation efficiency of MOF-199 particles was as high as 99.75% within 30 s at an initial DBT concentration of 50 ppmw and a dosage of MOF-199 of 5 wt.%. More importantly, MOF-199 can be successfully regenerated using H2O2 oxidation at the laboratory scale. The exceptionally high removal efficiency, fast separation speed, low cost and simple equipment make this simultaneous adsorption-separation hydrocyclone process a promising deep-desulfurization method.Download high-res image (196KB)Download full-size image

The primary challenge in material design and fabrication is the achievement of excellent performance, economic materials, and fast and convenient synthesis for real-world applications. We tackled this challenge via ultrafast synthesis of core–shell 13X@NaA zeolite composites within only 30 min. Via plasma treatment, more silanol groups on the surface of 13X powders and hydroxyl radicals in the NaA precursor gel result in the accelerated formation of the NaA crystal shell. After potassium ion exchange to different degrees, the obtained 13X@NaKA composites exhibit extremely high selectivity of 149–380 for CO2 over N2 and maintain good capacity of 3.41–1.84 mmol g−1. Our study provides a promising approach for the synthesis of core–shell zeolite composites as economic materials for further multiple applications.

•Core-shell zeolite@mesoporous silica-supported-amine hybrids (5A@MSAs) were synthesized.•5A@MSAs exhibited excellent CO2 adsorption capacity (5.05 mmol/g) even in the presence of water.•PEI shell dynamically hindered H2O molecules diffusion into 5A core through the chemical adsorption.•5A core maintained its good CO2 adsorption performance with the designed core@shell structure.•5 A@MSA-30 demonstrates a very stable cyclic adsorption–desorption performance.The selective capture of CO2 under humid condition for the commercial adsorbents has always been a great challenge. Here, we come up with a simple and effective solution, i.e., fabrication a shell around the commercial zeolite particle which can dynamically hinder the diffusion of water molecules into the zeolite core to maintain its good CO2 capacity even in the presence of water. By a sol–gel coating process and a polyethylenimine (PEI) impregnation process, a series of 5A zeolite-based hybrids with a shell of mesoporous silica-supported-amine (5A@MSAs) were fabricated. The performance of CO2 separation from the simulated flue gas (with 15:85 v/v CO2/N2 and moisture) was investigated by TG and MS in a flow system. Among the obtained adsorbents, 5A@MSA-30 was demonstrated to be the best candidate for CO2 capture from the simulated humid flue gas, with the CO2 uptake as high as 5.05 mmol/g at 298 K. The results of 10 cyclic adsorption/desorption operation suggested that the PEI molecules can be stably holden in the mesoporous silica shell, resulting in a remained CO2 adsorption capacity. The amine modified zeolite not only maintained but also significantly promoted the ability of CO2 capture under humid condition; therefore, it would be a promising solution for the commercial adsorbents to capture CO2 in the presence of water.

Amine-impregnated solid sorbents have been approved as one of the promising sorbents for CO2 capture. However, the low adsorption rate seriously limits their real application. Herein, we synthesized the mesoporous multilamellar silica vesicle (MMSV) and used them as a novel support for the impregnation of polyethylenimine (PEI). The mesoporous multilamellar structure, as well as the presence of surfactant templates, significantly improved the dispersion of PEI in sorbents and hence improved both adsorption capacity and adsorption rate simultaneously. Among various MMSV-PEIs samples, MMSV(a)-PEI-60% showed the best CO2 adsorption capacity, up to 4.73 mmol/g in pure and dry CO2 flow at 90 °C, and even exhibited a 22% enhancement in humid CO2 flow at 75 °C. Moreover, it also presented good adsorption/desorption cyclic performance. The kinetic study showed that the second-order kinetic model fitted quite well for dynamic CO2 adsorption, and the adsorption rate constants revealed its faster adsorption rate and higher amine efficiency compared with most reported amine-impregnated sorbents.

In situ interfacial growth of nanoparticles induced by the Pickering emulsion is a novel and convenient method for preparing hybrids/composites with specific tasks. For the first time, magnetic PMMA@Fe3O4/Cu3(BTC)2 hollow microspheres were produced by one-pot Pickering emulsion using Fe3O4 nanoparticle (NP) stabilizer. The Fe3O4 Pickering emulsion provided a large oil/water interface area for the in situ growth of Cu3(BTC)2 nanocrystals and further interfacial polymerization of polymethyl methacrylate (PMMA). The hollow hybrid microspheres showed synergetic multi-functions, including the magnetic separation property caused by Fe3O4 NPs, the reverse thermal expansion by PMMA, and the adsorption enhanced permeation by porous Cu3(BTC)2 NPs. When it was used as the drug carrier for ibuprofen, the good loading capacity and the controllable release duration confirmed its good properties. Moreover, all the realized synergetic advantages further reveled the potential promising applications of the interfacial synthesis by Pickering emulsion method.

Infinite coordination polymers are recognized as excellent platform for functionalization. Dithienylethene motifs, which are one of the most attractive functional moieties, were incorporated into an infinite coordination polymer, to deliver a “smart” porous material that can response to external stimuli. The obtained dithienylethene-based infinite coordination polymers (named Cu-DTEDBA) share the advantages of both infinite coordination polymers (porosity and stability) and dithienylethene motifs (photochromism). The physical and chemical properties of Cu-DTEDBA were characterized by FTIR, TEM, SEM, XRD, TGA, UV–vis, EDX and BET. Moreover, the combination of dithienylethene and infinite coordination polymers gives rise to a synergistic effect, which induces functional behaviors of ammonia sensor applications. Both open and closed forms of Cu-DTEDBA exhibit distinct colorimetric change upon exposure to gaseous ammonia, which is not observed in dithienylethene free molecules.The incorporation of dithienylethene motifs into the skeleton of infinite coordination polymers gives rise to a synergistic effect, inducing functional behaviors of ammonia sensing applications in addition to simple photochromism.

Most organic dyes dissipate their excitation energy in the aggregated state because of the “aggregation-caused quenching” effect, deteriorating their application in optoelectronic devices. To prevent the “aggregation-caused quenching” effect, we incorporate a dye-based fluorophore into a porous organic polymer skeleton because porosity would allow the spatial isolation of fluorophores to maintain their emission. Tuning the fraction of fluorophores in the skeleton of FL-SNW-DPPs could spread the emission color coverage from red to blue in both solid-state and suspension. More importantly, the combination of fluorescence and porosity of FL-SNW-DPPs would provide more space to transduce the molecular interaction between adsorbed analytes and fluorophores to the detectable changes in light emission, leading to the fluorescence-off or fluorescence-on detection of electron-deficient or electron-rich analytes.

For the real industrial process of CO2 capture, it is still a great challenge for adsorbents to exhibit excellent CO2 adsorption capacity in the presence of water. By combining a pre-seeding process and a two-step temperature controlling crystallization, a zeolitic imidazolate framework (ZIF-8) shell is introduced on the commercial zeolite adsorbent (5A) core to produce a series of 5A@ZIF-8 composites with an enhanced surface hydrophobicity. Each 5A@ZIF-8 composite exhibits a dynamic hydrophobic hindrance effect for the separation of CO2 from the simulated humid flue gas (15% CO2 and 90% humidity at 298 K). Among these, the CO2 adsorption capacity and the CO2/H2O selectivity of 5A@ZIF-8(I) can be as high as 2.67 mmol g−1 and 6.61, respectively, at the optimized adsorption time of 10 min. More importantly, over 10 adsorption–desorption cycles, there is almost no degradation of the adsorption performance. Therefore, the novel strategy of utilizing the dynamic hydrophobic hindrance effect through a core–shell structure would be a good solution for improving the CO2 separation performance in practical applications.

•MCF/Ag composites showed a high catalytic activity for 4-nitrophenol reduction.•A plasma-assisted synthesis method was proposed to fabricate MCF/Ag composites.•Plasma-treated MCFs provided more silanol groups to coordinate with Ag cations.•Power strength of plasma treatment affected the morphology of Ag nanoparticles.Silver nanoparticle is an important catalyst for many chemical reactions and usually demands complex synthesis technology. In this work, a convenient and efficient plasma-assisted synthesis method was proposed to synthesize a new type of composite catalyst with Ag nanoparticles immobilized in 3D mesoporous cellular foams (MCFs) of silica. The plasma treatment under O2 atmosphere provided more activated silanol groups on the surface of MCF for the immobilization of Ag nanoparticles. The properties of immobilized Ag nanoparticles, such as smaller average size, higher loading, and better dispersion state greatly improved the reaction rate of the catalytic reduction of 4-nitrophenol (4-NP). Among them, with an average size of 6.0 nm and 2.6 wt% immobilized Ag nanoparticles, the catalyst MCF-100-Ag-0.01 showed the best catalytic activity for the reduction of 4-NP, that the apparent reduction rate constant was as large as 2.66 × 10−2 s−1, and the turnover frequency coefficient was as extremely high as 8.97 × 1018 molecules g−1 s−1. The MCF-n-Ag-m composites could be expected as attractive catalysts for many other catalytic reactions. More importantly, this plasma-assisted synthesis approach could be a convenient way for the synthesis of highly active catalysts by immobilizing various types of metal nanoparticles in porous materials.By DBD plasma treatment in O2 atmosphere, 3D mesoporous cellular foams (MCFs) of silica provided more activated silanol groups for the immobilization of Ag nanoparticles. Among various obtained catalysts, with an average size of 6.0 nm and containing 2.6 wt% Ag nanoparticles, MCF-100-Ag-0.01 showed the best catalytic activity for the reduction of 4-nitrophenol, with a large apparent reduction rate constant of 2.66 × 10−2 s−1, and extremely high TOF coefficient of 8.97 × 1018 molecules g−1 s−1.

A novel method of an in situ interfacial growth of nanoparticles induced by a Pickering emulsion was proposed for the fabrication of hollow composites. With the interfacial growth of ZIF-8 nanoparticles at the n-octanol/water interface of a Pickering emulsion stabilized by graphene oxide (GO), the hollow ZIF-8/GO composite was obtained.

The world is becoming more stringent on lowering the sulfur concentrations in fuels. To fulfill this expectation, a new type of magnetic desulfurization adsorbent, Fe3O4@PAA@MOF-199, was designed and fabricated using a facile two-step assembly approach, in which PAA inventively acted like a bridge to incorporate different amounts of magnetite Fe3O4 into a MOF-199 crystal matrix. Fe3O4@PAA@MOF-199s were demonstrated to be efficient adsorbents for the removal of S-compounds, such as thiophene, benzothiophene (BT) and dibenzothiophene (DBT), from a model fuel, and the sulfur saturated adsorption capacity followed the order of DBT > BT > thiophene. The magnetization of Fe3O4@PAA@MOF-199s ensured that the adsorbents had good performance in magnetic separation. The relative high adsorption capacity, the separation efficiency, as well as the stable recyclability indicated that magnetic Fe3O4@PAA@MOF-199 would be a promising adsorbent in adsorptive desulfurization.

The mixed micelle template approach is one of the most promising synthesis methods for hierarchical porous materials. Although considerable research efforts have been made to explore the formation mechanism, explicit theoretical guidance for appropriately choosing templates is still not available. We found that the phase separation occurring in the mixed micelles would be the key point for the synthesis of hierarchical porous materials. Herein, the pseudophase separation theory for the critical micelle concentration (cmc) combined with the Flory–Huggins theory for the chain molecular mixture were employed to investigate the properties of mixed surfactant aqueous solutions. The cmc values of mixed surfactant solutions were experimentally determined to calculate the Flory–Huggins interaction parameter between two surfactants, χ. When χ is larger than the critical value, χc, the phase separation would occur within the micellar phase, resulting in two types of mixed micelles with different surfactant compositions, and hence different sizes, which could be used as the dual-template to induce bimodal pores with different pore sizes. Therefore, the Flory–Huggins theory could be a theoretical basis to judge whether the mixed surfactants were the suitable templates for inducing hierarchical porous materials. We chose cetyltrimethylammonium bromide (CTAB) and n-octylamine (OA) as a testing system. The phase separation behavior of the mixed solutions as well as the successful synthesis of hierarchical porous materials by this dual-template indicated the feasibility of preparing hierarchical porous materials based on the concept of phase separation of the mixed micelles.

•Ionic liquid of [Omim]Cl was used to synthesize thin graphene with a thickness of 2 nm.•Li4Ti5O12 nanoparticles (∼20 nm) were in situ grown on the surface of thin graphene.•The synthesized electrode exhibits excellent reversibility and high-rate performance.•The reversible capacity of the electrode decreases only 8.5% from 0.2 to 20 C.Nano-crystalline Li4Ti5O12 with an average size of 18 nm was in situ grown on graphene sheets using ionic liquid of C12H23ClN2 [Omim]Cl as the exfoliated agent. Such unique nanostructure provides a high electrode/electrolyte area for the electron transport and the nanosized Li4Ti5O12 leads to a short path for the lithium ion transfer. When used as an anode material for lithium-ion battery, the Li4Ti5O12/graphene nanostructure exhibits excellent reversibility (159 mAh g−1 at 0.5 C after 100 cycles) and high-rate performance (162 mAh g−1 at 0.2 C, 148.5 mAh g−1 at 20 C).A novel Li4Ti5O12/graphene microstructure was designed and synthesized using as anode material for lithium storage with high-rate performance.

Composing of both zeolite and mesoporous structures, micro/mesoporous composites exhibit promising CO2 capture capabilities. In this work, a full-atomic mimetic 5A-MCM-41 structure with bimodal pores has been constructed, in which the microporous structure of 5A zeolite is constructed and optimized based on zeolite A with Ca and Na cations introduced; whereas the mesoporous MCM-41 structure is produced by caving the cylindrical pores in the obtained 5A zeolite matrix. CO2 adsorption on 5A-MCM-41 has been simulated by the grand canonical Monte Carlo (GCMC). The simulation results demonstrated that CO2 is preferentially adsorbed in micropores, and the CO2 adsorption capacity and its isosteric heat on 5A-MCM-41 are much larger than those of N2. The CO2 selectivity of 5A-MCM-41 results from the electrostatic interaction of the quadrupole CO2 molecule with Ca2+ cations of the zeolite. Furthermore, the hierarchical micro/mesoporous composites are synthesized to verify the simulated predictions. By the hydrothermal reaction using 5A zeolite “seeds” as the silicon source and hexadecyl trimethylammonium bromide (CTAB) as the mesoporous template, 5A-MCM-41 composites are obtained, the characteristic results show that typical 5A microporous structure is remained and disordered mesoporous networks are produced in the composites. Moreover, the CO2 adsorption capacity of the 5A-MCM-41 composites can reach as high as 4.08 mmol/g at 100 kPa and 298 K. These observations have been strongly supported that micro/mesoporous composites with metal ions located would be promising adsorbents for CO2 separation.

A series of flat-sheet asymmetric mixed matrix membranes (MMMs) have been fabricated with MOF-5, Cu3(BTC)2, and MIL-53(Al) as fillers and PI polymer as a matrix through the dry–wet phase inversion method. After the surface modification by coating a PAA solution (15% wt) on the top of the obtained membrane, a thin defect-free selective skin in the MMM is obtained. The permeance of various gases such as H2, He, CH4, N2, and CO2 and their gas pair selectivity have been investigated, respectively. The results show that Cu3(BTC)2/PI MMM possesses the best gas separation performance with H2 permeance of 0.44 GPU and H2/CH4 selectivity of 100. In addition, the mechanism of MOF fillers in MMMs has been further revealed by the interaction analysis between MOF fillers and PI chains.

By impregnating polyethylenimine (PEI) into silica mesocellular foam with the template remaining (MCF(a)), a novel sorbent with both high CO2 adsorption capacity and high thermal stability was obtained. The remaining P123 template in the MCF played a great role in promoting the CO2 adsorption capacity, which could be 4.5 mmol·g–1 (adsorbent) when the amount of amine loading and the adsorption temperature were optimized as 60% and at 70 °C for the sample MCF(a)/PEI. Meanwhile, MCF(a)/PEI had a high thermal stability and selectivity, after 10 adsorption–desorption cycles, MCF(a)/PEI almost held a constant adsorption capacity; for different compositions of CO2 and N2 mixed gases, it always kept a high adsorption selectivity of CO2/N2. The mechanism of the template synergistic effect was elucidated by the result of a second-order rate law through CO2 adsorption kinetic studies. Moreover, as predicted by the Langmuir adsorption model with n = 2 (two active adsorption sites for one CO2 molecule), the adsorption enthalpy was calculated as about −85 kJ·mol–1, a value which belonged to typical chemical adsorption.

CO2 adsorption properties on Mg modified silica mesoporous materials were investigated. By using the methods of co-condensation, dispersion and ion-exchange, Mg2+ was introduced into SBA-15 and MCM-41, and transformed into MgO in the calcination process. The basic MgO can provide active sites to enhance the acidic CO2 adsorption capacity. To improve the amount and the dispersion state of the loading MgO, the optimized modification conditions were also investigated. The XRD and TEM characteristic results, as well as the CO2 adsorption performance showed that the CO2 adsorption capacity not only depended on the pore structures of MCM-41 and SBA-15, but also on the improvement of the dispersion state of MgO by modification. Among various Mg modified silica mesoporous materials, the CO2 adsorption capacity increased from 0.42 mmol g−1 of pure silica SBA-15 to 1.35 mmol g−1 of Mg–Al–SBA-15-I1 by the ion-exchange method enhanced with Al3+ synergism. Moreover, it also increased from 0.67 mmol g−1 of pure silica MCM-41 to 1.32 mmol g−1 of Mg–EDA–MCM-41-D10 by the dispersion method enhanced with the incorporation of ethane diamine. The stability test by 10 CO2 adsorption/desorption cycles showed Mg–urea–MCM-41-D10 possessed quite good recyclability.Highlights► Dispersion, co-condensation and ionic exchange methods were adopted to impregnate Mg. ► Highly dispersed state of MgO is the key point to improve CO2 adsorption capacity. ► Amine modification can provide the ligand for Mg2+ to increase MgO dispersion state. ► Al3+ can attract Mg2+ dispersed in channels to improve CO2 adsorption synergistically.

A series of micro/mesoporous silica composites were synthesized with P123 and imidazolium ILs ([Cnmim]X) as the co-templates. [Cnmim]X showed notable synergic interaction with P123. By changing the alkyl chain length n in methylimidazolium, ring-like micropores were observed in the wall of the mesoporous materials when n = 4. While increasing n to 10, micropores and mesopores were found in different separated regions. Various anions of Cl–, Br–, and BF4– of ILs have little effect on the aggregation behavior of P123/C4X mixed micelles. The strong hydrogen bonding effect of BF4– has resulted in the ordered mesoporous channels with numerous micropores in the wall at a low temperature of 313 K. Hydrophobic C4PF6 can only be solubilized in the core of P123 micelles, which resulted in the swelling of P123/C4PF6 mixed aggregates and the ordered hexagonal porous silica materials at 313 K. The fundamental understanding of the synergic interaction and formation mechanisms of various porous silica materials can provide a general convenient way toward a rational design and synthesis of the micro/mesoporous composites.

Novel CO2 adsorbents were prepared by grafting aminosilanes on mesoporous silica MCM-41. The effects of solvent and temperature on the grafting of the amine group were studied. The results of thermal gravimetric analysis of the AEAPDMS-MCM-41s produced in different solvents revealed that the nonpolar solvent toluene and the aprotic polar solvent THF are beneficial to the amine group modification reaction. The CO2 adsorption capacity of AEAPDMS-MCM-41s produced in toluene had a relatively high value of 2.20 mmol⋅g−1.

Adsorption of pure CO2 and N2 and separation of CO2/N2 mixture in MFI zeolite and MFI/MCM-41 micro/mesoporous composite have been studied by using atomistic simulations. Fully atomistic models of MFI and MFI/MCM-41 are constructed and characterized. A bimodal pore size distribution is observed in MFI/MCM-41 from simulated small- and broad-angle X-ray diffraction patterns. The density of MFI/MCM-41 is lower than MFI, while its free volume and specific surface area are greater than MFI due to the presence of mesopores. CO2 is preferentially adsorbed than N2, and thus, the loading and isosteric heat of CO2 are greater than N2 in both MFI and MFI/MCM-41. CO2 isotherm in MFI/MCM-41 is similar to that in MFI at low pressures, but resembles that in MCM-41 at high pressures. N2 shows similar amount of loading in MFI, MCM-41 and MFI/MCM-41. The selectivity of CO2 over N2 in the three adsorbents decreases in the order of MFI>MFI/MCM-41>MCM-41. With increasing pressure, the selectivity increases in MFI and MFI/MCM-41, but decreases in MCM-41. The self-diffusivity of CO2 and N2 in MFI decreases as loading increases, while in MFI/MCM-41, it first increases and then drops.

Dielectric materials with ultralow dielectric constants (<2.0) are desiderated in the integrated circuits (ICs). In this work, we fabricated polyimide (PI) films consisting of mesoporous nanoparticles (MPNPs-PF) through a one-step solvent evaporation induced self-assembly method. Poly(amic acid) was selected as the polymer matrix; and the commercial triblock copolymer F127 was adopted as the mesoporous template as well as the nanoparticle morphology controller, respectively. After imidization and template removal, the dense films consisting of closed-packed PI nanoparticles with an average diameter less than 50 nm were obtained. Since the nanoparticles were fully composed of worm-like mesopores, the dielectric constant (k value) of the resultant porous PI films can reach as low as 1.92. When the reactive end-capper of maleic anhydride (MA) was blended into poly(amic acid), k value decreased even lower to 1.86. Meanwhile, the modulus of the resultant porous PI films was higher than 1 GPa.Graphical abstractThe ultralow dielectric polyimide films consisting of mesoporous nanoparticles were fabricated via one-step assembly method. The nanoparticles were controlled as 50 nm with 1–2 nm mesopores inside. Both the mesopores inside and the interspaces among the nanoparticles contributed to the porosity of the resultant PI film, endowing the resultant MPNPs-PF an ultra-low k value of 1.86.Highlights► One-step fabrication of polyimide film consisting of mesoporous nanoparticles. ► F127 acted as both the mesoporous template and nanoparticle morphology controller. ► The average diameter of the nanoparticles was less than 50 nm. ► The k value reached as low as 1.92. ► The formation procedure of resultant porous PI film was studied.

A series of composite membranes of poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (P123) and polyacrylamide (PAM) have been successfully prepared by solvent-evaporation-induced self-assembly. Micellar self-assembly of P123 in aqueous solution plays an important role as a model for the formation of composite membranes. XRD patterns show that the synthesized compositions are in a lamellar mesostructure. The lattice spacing changes with P123 concentration: the higher the concentration of P123, the smaller the lattice spacing of the composite membranes. The data on sizes and zeta potentials of pure p-PAM aggregates, P123 micelles, p-PAM/P123 mixtures, and c-PAM/P123 composite aggregates suggest that interactions take place between PAM and P123 aggregations. The fabrication of the lamellar membranes via water-evaporation-induced self-assembly is recorded by fluorescent emission spectroscopy and dynamic light-scattering methods. Based on analysis of the results, a tentative mechanism for the formation of the lamellar membranes has been proposed.A possible schematic process of the transformation of the morphology of the composite aggregates formed by hydrogen bonds during the process of solvent-evaporation-induced self-assembly.

Immobilization of hemoglobin (Hb) in SBA-15 with various pore sizes by physical adsorption was studied. The structure changes of mesoporous SBA-15 before and after the immobilization of Hb were characterized by N2 adsorption isotherms, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Ultraviolet-visible spectroscopy (UV). The results indicate that SBA-15 is a good support for the immobilization of Hb due to its regular structure, large pore diameter, and high surface area. After immobilization of Hb, the regular structure of SBA-15 is still kept, but the pore diameter, pore volume and surface area decrease. With the increase of pore size, the binding amount and leaching amount of Hb increase. There is a maximum binding amount of Hb up to 355.2 mg/g SBA-15 when pore size is 8.9 nm. It is suggested that the immobilization of Hb depends significantly on the pore size of SBA-15.

Novel CO2 adsorbents were prepared by grafting two different aminosilanes on mesoporous silica MCM-41 and SBA-15. The properties of the mesoporous materials before and after surface modification were investigated by powder X-ray diffraction (XRD) pattern, solid-state 29Si nuclear magnetic resonance (NMR), Fourier transform infrared (FT-IR) spectra, and measurements of N2 adsorption and desorption isothermal, which confirmed that aminosilanes were grafted on the surface of the channels in the mesoporous materials. Thermogravimetry analysis (TGA) evaluated the amount of grafted amine to be about 1.5–2.9 mmol·g−1. The CO2 adsorption capacity of MCM-41 increased from 0.67 mmol·g−1 to 2.20 mmol·g−1 after AEAPMDS (N-β-(aminoethyl)-γ-aminopropyl dimethoxy methylsilane) modification (p=101 kPa) at room temperature. The studies of the mechanism of CO2 adsorption suggested that there were two main contributions to the increase: the chemical adsorption based on the active sites of amine groups and the capillary condensation caused by the nano-scale channels of the mesoporous materials.

TiO2 microspheres containing carbon have been synthesized viaa one-pot hydrothermal process using CTAB as the mesoporous template and nanoparticle stabilizer and Ti(SO4)2 and sucrose as titanium and carbon precursors, respectively. Through well designed calcinations, TiO2 microspheres with various amounts of carbon-residue, such as core/shell C@TiO2, hollow neat H–TiO2, and hollow C/TiO2 composites, are obtained. When these microspheres are used as anode materials for lithium ion batteries, the lithium storage performance is significantly influenced by the structure and carbon-residue. With a thin shell of TiO2 nanoparticles and carbon-residue, the capacity of hollow C/TiO2 composites maintains at 143.3 mA·h·g− 1 at 0.5 C (83.5 mA·g− 1) after 100 cycles. Moreover, after high rate charge/discharge cycles from 0.2 C to 20 C and back to 0.2 C again, the reversible capacity recovers atas high as 195.1 mA·h·g− 1 with respect to its initial value of 205.0 mA·h·g− 1. The results of cycle voltammograms and electrochemical impedance spectroscopy further reveal that Li+ insertion/extraction processes are reversible, and the diffusion coefficient of Li+ in the hollow C/TiO2 composites is much higher than those of others, because the hollow structure can act as the ion-buffering reservoir and facilitate Li+ transfer from both sides of the shell, and the carbon-residue in the shell improves the conductivity as well.TiO2 microspheres with various amounts of carbon-residue, such as core/shell C@TiO2, hollow neat H–TiO2, and hollow C/TiO2 composites have been obtained viaa one-pot hydrothermal process. With a thin shell of TiO2 nanoparticles and carbon-residues, the capacity of hollow C/TiO2 composites maintains at 143.3 mAh·g− 1 at 0.5 C (83.5 mA·g− 1) after 100 cycles.Download full-size image

Most organic dyes dissipate their excitation energy in the aggregated state because of the “aggregation-caused quenching” effect, deteriorating their application in optoelectronic devices. To prevent the “aggregation-caused quenching” effect, we incorporate a dye-based fluorophore into a porous organic polymer skeleton because porosity would allow the spatial isolation of fluorophores to maintain their emission. Tuning the fraction of fluorophores in the skeleton of FL-SNW-DPPs could spread the emission color coverage from red to blue in both solid-state and suspension. More importantly, the combination of fluorescence and porosity of FL-SNW-DPPs would provide more space to transduce the molecular interaction between adsorbed analytes and fluorophores to the detectable changes in light emission, leading to the fluorescence-off or fluorescence-on detection of electron-deficient or electron-rich analytes.

For the real industrial process of CO2 capture, it is still a great challenge for adsorbents to exhibit excellent CO2 adsorption capacity in the presence of water. By combining a pre-seeding process and a two-step temperature controlling crystallization, a zeolitic imidazolate framework (ZIF-8) shell is introduced on the commercial zeolite adsorbent (5A) core to produce a series of 5A@ZIF-8 composites with an enhanced surface hydrophobicity. Each 5A@ZIF-8 composite exhibits a dynamic hydrophobic hindrance effect for the separation of CO2 from the simulated humid flue gas (15% CO2 and 90% humidity at 298 K). Among these, the CO2 adsorption capacity and the CO2/H2O selectivity of 5A@ZIF-8(I) can be as high as 2.67 mmol g−1 and 6.61, respectively, at the optimized adsorption time of 10 min. More importantly, over 10 adsorption–desorption cycles, there is almost no degradation of the adsorption performance. Therefore, the novel strategy of utilizing the dynamic hydrophobic hindrance effect through a core–shell structure would be a good solution for improving the CO2 separation performance in practical applications.