Porous carbon materials with developed porosity,high surface area and good thermal-and chemicalresistance are advantageous for gas adsorption and separation.However,most carbon adsorbents are in powder form which exhi...Porous carbon materials with developed porosity,high surface area and good thermal-and chemicalresistance are advantageous for gas adsorption and separation.However,most carbon adsorbents are in powder form which exhibit high pressure drop when deployed in practical separation bed.While monolithic carbons have largely addressed the pulverization problem and preserved kinetics and usually suffer from abrasion during multiple adsorption-desorption cycles.Herein,we proposed the designed synthesis of mechanically robust carbon monoliths with hierarchical pores,solid nitrogen-containing framework.The synthesis started with the polymerization of resorcinol and formaldehyde under weakly acidic conditions generated from cyanuric acid,and then an appropriate amount of hexamethylenetetramine(HMTA)was added as a crosslinker to prompt the formation of three dimensional frameworks.After carbonization process,the as-obtained porous carbon monoliths have a high radial compressive strength of 886 N/cm as well as a BET specific surface area of up to 683 m2/g.At approximately 1 bar,the CO2 equilibrium capacities of the monoliths are in the range of 3.1–4.0 mmol/g at 273 K and of 2.3–3.0 mmol/g at 298 K,exhibiting high selectivity for the capture of CO2 over N2 from a stream which consists of 16.7%(v%)CO2 in N2.Meanwhile,they undergo a facile CO2 release in an argon stream at 298 K,indicating a good regeneration capacity.After cycle testing,sieving and regeneration,the adsorbent has no mass loss,compared to that of its fresh counterpart.展开更多
Binary oxide systems（Cu Cr2O4, Cu Co2O4）, deposited onto cordierite monoliths of honeycomb structure with a second support（finely dispersed Al2O3）, were prepared as filters for catalytic combustion of diesel soot ...Binary oxide systems（Cu Cr2O4, Cu Co2O4）, deposited onto cordierite monoliths of honeycomb structure with a second support（finely dispersed Al2O3）, were prepared as filters for catalytic combustion of diesel soot using internal combustion engine’s gas exhausts（O2, NOx, H2 O, CO2） and O3 as oxidizing agents. It is shown that the second support increases soot capacity of aforementioned filters, and causes dispersion of the particles of spinel phases as active components enhancing thereby catalyst activity and selectivity of soot combustion to CO2. Oxidants used can be arranged with reference to decreasing their activity in a following series： O3 NO2〉 H2 O 〉 NO 〉 O2〉 CO2. Ozone proved to be the most efficient oxidizing agent： the diesel soot combustion by O3 occurs intensively（in the presence of copper chromite based catalyst） even at closing to ambient temperatures.Results obtained give a basis for the conclusion that using a catalytic coating on soot filters in the form of aforementioned binary oxide systems and ozone as the initiator of the oxidation processes is a promising approach in solving the problem of comprehensive purification of automotive exhaust gases at relatively low temperatures, known as the ＂cold start＂ problem.展开更多
Metal-organic frameworks(MOFs)have been extensively considered as one of the most promising types of porous and crystalline organic-inorganic materials,thanks to their large specific surface area,high porosity,tailora...Metal-organic frameworks(MOFs)have been extensively considered as one of the most promising types of porous and crystalline organic-inorganic materials,thanks to their large specific surface area,high porosity,tailorable structures and compositions,diverse functionalities,and well-controlled pore/size distribution.However,most developed MOFs are in powder forms,which still have some technical challenges,including abrasion,dustiness,low packing densities,clogging,mass/heat transfer limitation,environmental pollution,and mechanical instability during the packing process,that restrict their applicability in industrial applications.Therefore,in recent years,attention has focused on techniques to convert MOF powders into macroscopic materials like beads,membranes,monoliths,gel/sponges,and nanofibers to overcome these challenges.Three-dimensional(3D)printing technology has achieved much interest because it can produce many high-resolution macroscopic frameworks with complex shapes and geometries from digital models.Therefore,this review summarizes the combination of different 3D printing strategies with MOFs and MOF-based materials for fabricating 3D-printed MOF monoliths and their environmental applications,emphasizing water treatment and gas adsorption/separation applications.Herein,the various strategies for the fabrication of 3D-printed MOF monoliths,such as direct ink writing,seed-assisted in-situ growth,coordination replication from solid precursors,matrix incorporation,selective laser sintering,and digital light processing,are described with the relevant examples.Finally,future directions and challenges of 3D-printed MOF monoliths are also presented to better plan future trajectories in the shaping of MOF materials with improved control over the structure,composition,and textural properties of 3D-printed MOF monoliths.展开更多
Hierarchically porous FAU monoliths were synthesized via the gel pre-aging route using seed gel as directing agent andα-Al2O3 as monolithic carrier.The as-synthesized samples were characterized by means of the Fourie...Hierarchically porous FAU monoliths were synthesized via the gel pre-aging route using seed gel as directing agent andα-Al2O3 as monolithic carrier.The as-synthesized samples were characterized by means of the Fourier transform infrared spectroscopy(FT-IR),X-ray powder diffraction(XRD),scanning electron microscopy(SEM),and N2 adsorption techniques.The effects of seed gel,gel pre-treatment,and gel pre-aging step were determined,while the possible mechanism for formation of alumina composites via different synthesis processes were discussed.The results showed that the crystal size,the shape,and the loading of the supported FAU could be readily tuned by varying the composition of the crystallization gel without notably changing the structure ofα-Al2O3.The proposed seed gel pre-treating and gel pre-aging route are simple,reproducible,and practically easy to integrate triple porous structures into large-dimension monoliths,which are proved to be very effective in depositing pure FAU crystals on theα-Al2O3 skeleton surface and strengthening the interfacial interaction between them.Moreover,it may provide inspiration to the synthesis of other hierarchical zeolites.展开更多
The various advantages of organic polymer monoliths, including relatively simple preparation processes,abundant monomer availability, and a wide application range of pH, have attracted the attention of chromatographer...The various advantages of organic polymer monoliths, including relatively simple preparation processes,abundant monomer availability, and a wide application range of pH, have attracted the attention of chromatographers. Organic polymer monoliths prepared by traditional methods only have macropores and mesopores, and micropores of less than 50 nm are not commonly available. These typical monoliths are suitable for the separation of biological macromolecules such as proteins and nucleic acids, but their ability to separate small molecular compounds is poor. In recent years, researchers have successfully modified polymer monoliths to achieve uniform compact pore structures. In particular, microporous materials with pores of 50 nm or less that can provide a large enough surface area are the key to the separation of small molecules. In this review, preparation methods of polymer monoliths for high-performance liquid chromatography, including ultra-high cross-linking technology, post-surface modification, and the addition of nanomaterials, are discussed. Modified monolithic columns have been used successfully to separate small molecules with obvious improvements in column efficiency.展开更多
Liquid metal(LM)has become an emerging material paradigm in the electromagnetic interference shielding field owing to its excellent electrical conductivity.However,the processing of lightweight bulk LM composites with...Liquid metal(LM)has become an emerging material paradigm in the electromagnetic interference shielding field owing to its excellent electrical conductivity.However,the processing of lightweight bulk LM composites with finite package without leakage is still a great challenge,due to high surface tension and pump-out issues of LM.Here,a novel confined thermal expansion strategy based on expandable microsphere(EM)is proposed to develop a new class of LM-based monoliths with 3D continuous conductive network.The EM/LM monolith(EM/LMm)presents outstanding performance of lightweight like metallic aerogel(0.104 g cm^(-1)),high strength(3.43 MPa),super elasticity(90%strain),as well as excellent tailor ability and recyclability,rely on its unique gas-filled closed-cellular structure and refined LM network.Moreover,the assembled highly conducting EM/LMm exhibits a recorded shielding effectiveness(98.7 dB)over a broad frequency range of 8.2-40 GHz among reported LM-based composites at an ultra-low content of LM,and demonstrates excellent electromagnetic sealing capacity in practical electronics.The ternary EM/LM/Ni monoliths fabricated by the same approach could be promising universal design principles for multifunctional LM composites,and applicable in magnetic responsive actuator.展开更多
For delivering the nanoscaled extraordinary characteristics in macroscopical bulk,it is essential to integrate two-dimensional nanosheets into threedimensional(3D)porous monoliths,alternatively called as 3D architectu...For delivering the nanoscaled extraordinary characteristics in macroscopical bulk,it is essential to integrate two-dimensional nanosheets into threedimensional(3D)porous monoliths,alternatively called as 3D architectures,3D networks,or aerogels.The intersupported structure of porous monolithic 3D graphene(3DG)can prevent aggregation or restacking of graphene individuals,and the interconnected sp^(2) network of 3DG not only can provide the highway for the transport of electron/phonon but also can present continual cavities/channels for mass transfer.This review summarizes the synthesis methodology of 3DG porous monoliths and highlights the application for electric double-layer capacitors.Present challenges and future prospects about the manufacture and application of 3DG are also discussed.展开更多
A novelty method,frontal polymerization(FP),was employed to directly produce a series of polyacrylamide (PAM),poly(N-isopropylacrylamide)(PNIPAM) and acrylamide-N-isopropylacrylamide copolymer macroporous monoliths. F...A novelty method,frontal polymerization(FP),was employed to directly produce a series of polyacrylamide (PAM),poly(N-isopropylacrylamide)(PNIPAM) and acrylamide-N-isopropylacrylamide copolymer macroporous monoliths. Field emission scanning electronic microscope and mercury intrusion method were adopted to measure some parameters of these monoliths,such as frame,pore size distribution as well as porosity.Effects of types of monomer,thicker and surfactant on porous structure of monoliths were studied.A variet...展开更多
New energy sources that reduce the volume of harmful gases such as SO_(x)and NO_(x)released into the atmosphere are in constant development.Natural gas,primarily made up of methane,is being widely used as one reliable...New energy sources that reduce the volume of harmful gases such as SO_(x)and NO_(x)released into the atmosphere are in constant development.Natural gas,primarily made up of methane,is being widely used as one reliable energy source for heating and electricity generation due to its high combustion value.Currently,natural gas accounts for a large portion of electricity generation and chemical feedstock in manufacturing plastics and other commercially important organic chemicals.In the near future,natural gas will be widely used as a fuel for vehicles.Therefore,a practical storage device for its storage and transportation is very beneficial to the deployment of natural gas as an energy source for new technologies.In this tutorial review,biomaterials-based carbon monoliths(CMs),one kind of carbonaceous material,was reviewed as an adsorbent for natural gas(methane)adsorption and storage.展开更多
Zwitterionic sulfobetaine-based monolithic stationary phases have attracted increasing attention for their use in hydrophilic interaction chromatography.In this study,a novel hydrophilic polymeric monolith was fabrica...Zwitterionic sulfobetaine-based monolithic stationary phases have attracted increasing attention for their use in hydrophilic interaction chromatography.In this study,a novel hydrophilic polymeric monolith was fabricated through photo-initiated copolymerization of 3-(3-vinyl-1-imidazolio)-1-propanesulfonate(SBVI)with pentaerythritol triacrylate using methanol and tetrahydrofuran as the porogenic system.Notably,the duration for the preparation of this novel monolith was as little as 5 min,which was significantly shorter than that required for previously reported sulfobetaine-based monoliths prepared via conventional thermally initiated copolymerization.Moreover,these monoliths showed good morphology,permeability,porosity(62.4%),mechanical strength(over 15 MPa),column efficiency(51,230 plates/m),and reproducibility(relative standard deviations for all analytes were lower than 4.6%).Mechanistic studies indicated that strong hydrophilic and negative electrostatic interactions might be responsible for the retention of polar analytes on the zwitterionic SBVI-based monolith.In particular,the resulting monolith exhibited good anti-protein adhesion ability and low nonspecific protein adsorption.These excellent features seem to favor its application in bioanalysis.Therefore,the novel zwitterionic sulfobetaine-based monolith was successfully employed for the highly selective separation of small bioactive compounds and the efficient enrichment of N-glycopeptides from complex samples.In this study,we prepared a novel zwitterionic sulfobetaine-based monolith with good performance and developed a simpler and faster method for preparation of zwitterionic monoliths.展开更多
In this paper,hierarchically porous Fe2O3 /CuO composite monoliths were first successfully synthesized by a mild method using silica monoliths as templates.The structure of composite monoliths was characterized by X-r...In this paper,hierarchically porous Fe2O3 /CuO composite monoliths were first successfully synthesized by a mild method using silica monoliths as templates.The structure of composite monoliths was characterized by X-ray diffraction,scanning electron microscopy,nitrogen adsorption-desorption.The results indicated that the molar ratio of Fe to Cu had a great influence on the crystal phase of Fe2O3,pore size and the structure of the macroporous wall.The Fe2O3 /CuO composite monoliths consist of hierarchically macroporous and mesoporous structure,while the sample with the Fe/Cu molar ratio of 2：1 possesses tighter wall structure than other samples.It is expected that asprepared Fe2O3/CuO composite monoliths have potential applications in several fields as catalysts,catalyst supports,chemical sensors and high-performance liquid chromatography （HPLC）.展开更多
A new method for preparing LiLaNiO/γ(-Al2O3 monolithic catalyst was described and discussed. The catalyst, which was supported over the monolith, was evaluated in a POM to syngas process. Relative stable catalytic pr...A new method for preparing LiLaNiO/γ(-Al2O3 monolithic catalyst was described and discussed. The catalyst, which was supported over the monolith, was evaluated in a POM to syngas process. Relative stable catalytic properties during the 120 hours operation at atmospheric pressure were found for the catalyst. Under the high space velocity of 9.0×104l/(kg·（h）（CH4）, the conversion of methane came to 95.5%, and the selectivity of carbon monoxide was not below 96.0% at 1123K when ratio of the feedstock （CH4/O2） was equal to 2.0.展开更多
A new route to synthesize ZSM-5 monoliths with hierarchical pore structure has been referred to in this study. The successful incorporation of the macropores and mesopores within the ZSM-5 struc- ture was achieved thr...A new route to synthesize ZSM-5 monoliths with hierarchical pore structure has been referred to in this study. The successful incorporation of the macropores and mesopores within the ZSM-5 struc- ture was achieved through transforming the skeleton of the macroporous silica gel into zeolite ZSM-5 using carbon materials as the transitional template. The ZSM-5 crystal covered part of the macroporous material, and provided micropores to the macroporous silica gel. The structure of carbon monolith was studied after dissolving the silica contained in the carbon/silica composite.展开更多
Methane adsorption by different forms of activated carbon obtained from coffee husks, including monolith honeycomb and disc types, was studied by activation with zinc salts and potassium hydroxide at 298.15 K and 303....Methane adsorption by different forms of activated carbon obtained from coffee husks, including monolith honeycomb and disc types, was studied by activation with zinc salts and potassium hydroxide at 298.15 K and 303.15 K and pressures up to 30.00 atm in a volumetric adsorption apparatus. We observed increased methane adsorption capacity on a mass basis in the different activated carbon monoliths with increasing surface area, total pore volume and micropore volume, with the honeycomb type displaying the highest methane absorption capacity. The maximum volumetric methane uptake by the synthesised carbon monoliths was observed to be 130 V/V at 298.15 K and 30.00 atm for honeycomb monoliths synthesised with zinc chloride (ZnCl2) and Polyvinyl alcohol (PVA) as the binder. Adsorption calorimetry results were used to describe the interaction between vip molecules and the adsorbent at low surface coverage and the energetic heterogeneous surface nature of the adsorbent.展开更多
In this paper,the Ni/Al_(2)O_(3) monolithic catalyst with 15%Ni content was prepared using cordierite as a matrix,and the catalyst was modified with 10%NaOH to study the methanation performance of biomass gasification...In this paper,the Ni/Al_(2)O_(3) monolithic catalyst with 15%Ni content was prepared using cordierite as a matrix,and the catalyst was modified with 10%NaOH to study the methanation performance of biomass gasification simulated gas based on alkali-modified Ni/Al_(2)O_(3) monolithic catalyst.BET,TEM,H_(2)-TPR,XRD,CO_(2)-TPD and TG were used to characterize the physicochemical properties of the catalyst before and after modification.The results indicated that the CO conversion rate trends of unmodified and modified Ni/Al_(2)O_(3) monolithic catalysts over 2 h were fundamentally consistent.However,the Ni/Al_(2)O_(3) catalysts modified for 2 h demonstrated significantly enhanced performance compared to those modified for 1 h.Regarding CH4 selectivity,the modified Ni/Al_(2)O_(3) catalyst exhibited markedly better performance than the unmodified Ni/Al_(2)O_(3) catalyst,confirming the enhanced methane performance of the alkali-modified Ni/Al_(2)O_(3) monolithic catalyst.Under optimized conditions(H_(2)/CO volume ratio of 3∶1,space velocity of 10000 mL/(g·h),and temperature of 400℃),the methanation performance of the Ni/Al_(2)O_(3) monolithic catalyst modified for 2 h reached its peak,achieving a CO conversion rate of 97%with 100%CH4 selectivity.展开更多
Utilizing solar energy for sorbent regeneration during the CO_(2)swing adsorption process could potentially reduce CO_(2)capture costs.This study describes a new technique—solar thermal swing adsorption(STSA)for CO_(...Utilizing solar energy for sorbent regeneration during the CO_(2)swing adsorption process could potentially reduce CO_(2)capture costs.This study describes a new technique—solar thermal swing adsorption(STSA)for CO_(2)capture based on application of intermittent illumination onto porous carbon monolith(PCM)sorbents during the CO_(2)capture process.This allows CO_(2)to be selectively adsorbed on the sorbents during the light-off periods and thereafter released during the light-on periods due to the solar thermal effect.The freestanding and mechanically strong PCMs have rich ultramicropores with narrow pore size distributions,displaying relatively high CO_(2)adsorption capacity and high CO_(2)/N_(2) selectivity.Given the high CO_(2)capture performance,high solar thermal conversion efficiency,and high thermal conductivity,the PCM sorbents could achieve high CO_(2)capture rate of up to 0.226 kg·kgcarbon^(-1)·h^(-1)from a gas mixture of 20 vol.%CO_(2)/80 vol.%N_(2) under STSA conditions with a light intensity of 1000 W·m^(-2).In addition,the combination of STSA with the conventional vacuum swing adsorption technique further increases the CO_(2)working capacity.展开更多
Flexible electronics face critical challenges in achieving monolithic three-dimensional(3D)integration,including material compatibility,structural stability,and scalable fabrication methods.Inspired by the tactile sen...Flexible electronics face critical challenges in achieving monolithic three-dimensional(3D)integration,including material compatibility,structural stability,and scalable fabrication methods.Inspired by the tactile sensing mechanism of the human skin,we have developed a flexible monolithic 3D-integrated tactile sensing system based on a holey MXene paste,where each vertical one-body unit simultaneously functions as a microsupercapacitor and pressure sensor.The in-plane mesopores of MXene significantly improve ion accessibility,mitigate the self-stacking of nanosheets,and allow the holey MXene to multifunctionally act as a sensing material,an active electrode,and a conductive interconnect,thus drastically reducing the interface mismatch and enhancing the mechanical robustness.Furthermore,we fabricate a large-scale device using a blade-coating and stamping method,which demonstrates excellent mechanical flexibility,low-power consumption,rapid response,and stable long-term operation.As a proof-of-concept application,we integrate our sensing array into a smart access control system,leveraging deep learning to accurately identify users based on their unique pressing behaviors.This study provides a promising approach for designing highly integrated,intelligent,and flexible electronic systems for advanced human-computer interactions and personalized electronics.展开更多
Photonic neural networks(PNNs)of sufficiently large physical dimensions and high operation accuracies are envisaged as ideal candidates for breaking the major bottlenecks in the current artificial intelligence archite...Photonic neural networks(PNNs)of sufficiently large physical dimensions and high operation accuracies are envisaged as ideal candidates for breaking the major bottlenecks in the current artificial intelligence architectures in terms of latency,energy efficiency,and computational power.To achieve this vision,it is of vital importance to scale up the PNNs while simultaneously reducing the high demand on the dimensions required by them.The underlying cause of this strategy is the enormous gap between the scales of photonic and electronic integrated circuits.Here,we demonstrate monolithically integrated optical convolutional processors on thin film lithium niobate(TFLN)that harness inherent parallelism in photonics to enable large-scale programmable convolution kernels and,in turn,greatly reduce the dimensions required by subsequent fully connected layers.Experimental validation achieves high classification accuracies of 96%(86%)on the MNIST(Fashion-MNIST)dataset and 84.6%on the AG News dataset while dramatically reducing the required subsequent fully connected layer dimensions to 196×10(from 784×10)and 175×4(from 800×4),respectively.Furthermore,our devices can be driven by commercial field-programmable gate array systems;a unique advantage in addition to their scalable channel number and kernel size.Our architecture provides a solution to build practical machine learning photonic devices.展开更多
基金financially supported by a Joint Sino-German Research Project(21761132011)the National Natural Science Foundation of China(No.21776041)the Cheung Kong Scholars Programme of China(T2015036).
文摘Porous carbon materials with developed porosity,high surface area and good thermal-and chemicalresistance are advantageous for gas adsorption and separation.However,most carbon adsorbents are in powder form which exhibit high pressure drop when deployed in practical separation bed.While monolithic carbons have largely addressed the pulverization problem and preserved kinetics and usually suffer from abrasion during multiple adsorption-desorption cycles.Herein,we proposed the designed synthesis of mechanically robust carbon monoliths with hierarchical pores,solid nitrogen-containing framework.The synthesis started with the polymerization of resorcinol and formaldehyde under weakly acidic conditions generated from cyanuric acid,and then an appropriate amount of hexamethylenetetramine(HMTA)was added as a crosslinker to prompt the formation of three dimensional frameworks.After carbonization process,the as-obtained porous carbon monoliths have a high radial compressive strength of 886 N/cm as well as a BET specific surface area of up to 683 m2/g.At approximately 1 bar,the CO2 equilibrium capacities of the monoliths are in the range of 3.1–4.0 mmol/g at 273 K and of 2.3–3.0 mmol/g at 298 K,exhibiting high selectivity for the capture of CO2 over N2 from a stream which consists of 16.7%(v%)CO2 in N2.Meanwhile,they undergo a facile CO2 release in an argon stream at 298 K,indicating a good regeneration capacity.After cycle testing,sieving and regeneration,the adsorbent has no mass loss,compared to that of its fresh counterpart.
文摘Binary oxide systems（Cu Cr2O4, Cu Co2O4）, deposited onto cordierite monoliths of honeycomb structure with a second support（finely dispersed Al2O3）, were prepared as filters for catalytic combustion of diesel soot using internal combustion engine’s gas exhausts（O2, NOx, H2 O, CO2） and O3 as oxidizing agents. It is shown that the second support increases soot capacity of aforementioned filters, and causes dispersion of the particles of spinel phases as active components enhancing thereby catalyst activity and selectivity of soot combustion to CO2. Oxidants used can be arranged with reference to decreasing their activity in a following series： O3 NO2〉 H2 O 〉 NO 〉 O2〉 CO2. Ozone proved to be the most efficient oxidizing agent： the diesel soot combustion by O3 occurs intensively（in the presence of copper chromite based catalyst） even at closing to ambient temperatures.Results obtained give a basis for the conclusion that using a catalytic coating on soot filters in the form of aforementioned binary oxide systems and ozone as the initiator of the oxidation processes is a promising approach in solving the problem of comprehensive purification of automotive exhaust gases at relatively low temperatures, known as the ＂cold start＂ problem.
文摘Metal-organic frameworks(MOFs)have been extensively considered as one of the most promising types of porous and crystalline organic-inorganic materials,thanks to their large specific surface area,high porosity,tailorable structures and compositions,diverse functionalities,and well-controlled pore/size distribution.However,most developed MOFs are in powder forms,which still have some technical challenges,including abrasion,dustiness,low packing densities,clogging,mass/heat transfer limitation,environmental pollution,and mechanical instability during the packing process,that restrict their applicability in industrial applications.Therefore,in recent years,attention has focused on techniques to convert MOF powders into macroscopic materials like beads,membranes,monoliths,gel/sponges,and nanofibers to overcome these challenges.Three-dimensional(3D)printing technology has achieved much interest because it can produce many high-resolution macroscopic frameworks with complex shapes and geometries from digital models.Therefore,this review summarizes the combination of different 3D printing strategies with MOFs and MOF-based materials for fabricating 3D-printed MOF monoliths and their environmental applications,emphasizing water treatment and gas adsorption/separation applications.Herein,the various strategies for the fabrication of 3D-printed MOF monoliths,such as direct ink writing,seed-assisted in-situ growth,coordination replication from solid precursors,matrix incorporation,selective laser sintering,and digital light processing,are described with the relevant examples.Finally,future directions and challenges of 3D-printed MOF monoliths are also presented to better plan future trajectories in the shaping of MOF materials with improved control over the structure,composition,and textural properties of 3D-printed MOF monoliths.
基金This work was supported by the National Natural Science Foundation of China(No.61673004 and No.11472048)the Fundamental Research Funds for the Central Universities of China(XK1802-4).
文摘Hierarchically porous FAU monoliths were synthesized via the gel pre-aging route using seed gel as directing agent andα-Al2O3 as monolithic carrier.The as-synthesized samples were characterized by means of the Fourier transform infrared spectroscopy(FT-IR),X-ray powder diffraction(XRD),scanning electron microscopy(SEM),and N2 adsorption techniques.The effects of seed gel,gel pre-treatment,and gel pre-aging step were determined,while the possible mechanism for formation of alumina composites via different synthesis processes were discussed.The results showed that the crystal size,the shape,and the loading of the supported FAU could be readily tuned by varying the composition of the crystallization gel without notably changing the structure ofα-Al2O3.The proposed seed gel pre-treating and gel pre-aging route are simple,reproducible,and practically easy to integrate triple porous structures into large-dimension monoliths,which are proved to be very effective in depositing pure FAU crystals on theα-Al2O3 skeleton surface and strengthening the interfacial interaction between them.Moreover,it may provide inspiration to the synthesis of other hierarchical zeolites.
文摘The various advantages of organic polymer monoliths, including relatively simple preparation processes,abundant monomer availability, and a wide application range of pH, have attracted the attention of chromatographers. Organic polymer monoliths prepared by traditional methods only have macropores and mesopores, and micropores of less than 50 nm are not commonly available. These typical monoliths are suitable for the separation of biological macromolecules such as proteins and nucleic acids, but their ability to separate small molecular compounds is poor. In recent years, researchers have successfully modified polymer monoliths to achieve uniform compact pore structures. In particular, microporous materials with pores of 50 nm or less that can provide a large enough surface area are the key to the separation of small molecules. In this review, preparation methods of polymer monoliths for high-performance liquid chromatography, including ultra-high cross-linking technology, post-surface modification, and the addition of nanomaterials, are discussed. Modified monolithic columns have been used successfully to separate small molecules with obvious improvements in column efficiency.
基金This work was financially supported by the National Natural Science Foundation of China(62074154)China Postdoctoral Science Foundation(Grant No.2020M682983)+2 种基金Guangdong Basic and Applied Basic Research Fund(2020A1515110962,2020A1515110154)Shenzhen Basic Research Plan(JCYJ20180507182530279)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(2017411).
文摘Liquid metal(LM)has become an emerging material paradigm in the electromagnetic interference shielding field owing to its excellent electrical conductivity.However,the processing of lightweight bulk LM composites with finite package without leakage is still a great challenge,due to high surface tension and pump-out issues of LM.Here,a novel confined thermal expansion strategy based on expandable microsphere(EM)is proposed to develop a new class of LM-based monoliths with 3D continuous conductive network.The EM/LM monolith(EM/LMm)presents outstanding performance of lightweight like metallic aerogel(0.104 g cm^(-1)),high strength(3.43 MPa),super elasticity(90%strain),as well as excellent tailor ability and recyclability,rely on its unique gas-filled closed-cellular structure and refined LM network.Moreover,the assembled highly conducting EM/LMm exhibits a recorded shielding effectiveness(98.7 dB)over a broad frequency range of 8.2-40 GHz among reported LM-based composites at an ultra-low content of LM,and demonstrates excellent electromagnetic sealing capacity in practical electronics.The ternary EM/LM/Ni monoliths fabricated by the same approach could be promising universal design principles for multifunctional LM composites,and applicable in magnetic responsive actuator.
基金The authors acknowledge the support from National Natural Science Foundation of China(51972168,51672124,21603096)Program for Innovative Talents and Entrepreneur in Jiangsu,State Key Laboratory of Catalytic Materials and Reaction Engineering(RIPP,SINOPEC),and Technical Center of Nano Fabrication and Characterization of Nanjing University.
文摘For delivering the nanoscaled extraordinary characteristics in macroscopical bulk,it is essential to integrate two-dimensional nanosheets into threedimensional(3D)porous monoliths,alternatively called as 3D architectures,3D networks,or aerogels.The intersupported structure of porous monolithic 3D graphene(3DG)can prevent aggregation or restacking of graphene individuals,and the interconnected sp^(2) network of 3DG not only can provide the highway for the transport of electron/phonon but also can present continual cavities/channels for mass transfer.This review summarizes the synthesis methodology of 3DG porous monoliths and highlights the application for electric double-layer capacitors.Present challenges and future prospects about the manufacture and application of 3DG are also discussed.
基金supported by the National Natural Science Foundation of China(No50772013)
文摘A novelty method,frontal polymerization(FP),was employed to directly produce a series of polyacrylamide (PAM),poly(N-isopropylacrylamide)(PNIPAM) and acrylamide-N-isopropylacrylamide copolymer macroporous monoliths. Field emission scanning electronic microscope and mercury intrusion method were adopted to measure some parameters of these monoliths,such as frame,pore size distribution as well as porosity.Effects of types of monomer,thicker and surfactant on porous structure of monoliths were studied.A variet...
基金Acknowledgment is made to the Donors of the American Chemical Society Petroleum Research Fund for support of this research.
文摘New energy sources that reduce the volume of harmful gases such as SO_(x)and NO_(x)released into the atmosphere are in constant development.Natural gas,primarily made up of methane,is being widely used as one reliable energy source for heating and electricity generation due to its high combustion value.Currently,natural gas accounts for a large portion of electricity generation and chemical feedstock in manufacturing plastics and other commercially important organic chemicals.In the near future,natural gas will be widely used as a fuel for vehicles.Therefore,a practical storage device for its storage and transportation is very beneficial to the deployment of natural gas as an energy source for new technologies.In this tutorial review,biomaterials-based carbon monoliths(CMs),one kind of carbonaceous material,was reviewed as an adsorbent for natural gas(methane)adsorption and storage.
基金supported by the National Natural Science Foundation of China(Grant Nos.:82173773 and 82073806)the Natural Science Foundation of Guangdong Province,China(Grant Nos.:2020A1515010569 and 2021A0505030039)Science and Technology Program of Guangzhou,China(Grant No.:202102020729).
文摘Zwitterionic sulfobetaine-based monolithic stationary phases have attracted increasing attention for their use in hydrophilic interaction chromatography.In this study,a novel hydrophilic polymeric monolith was fabricated through photo-initiated copolymerization of 3-(3-vinyl-1-imidazolio)-1-propanesulfonate(SBVI)with pentaerythritol triacrylate using methanol and tetrahydrofuran as the porogenic system.Notably,the duration for the preparation of this novel monolith was as little as 5 min,which was significantly shorter than that required for previously reported sulfobetaine-based monoliths prepared via conventional thermally initiated copolymerization.Moreover,these monoliths showed good morphology,permeability,porosity(62.4%),mechanical strength(over 15 MPa),column efficiency(51,230 plates/m),and reproducibility(relative standard deviations for all analytes were lower than 4.6%).Mechanistic studies indicated that strong hydrophilic and negative electrostatic interactions might be responsible for the retention of polar analytes on the zwitterionic SBVI-based monolith.In particular,the resulting monolith exhibited good anti-protein adhesion ability and low nonspecific protein adsorption.These excellent features seem to favor its application in bioanalysis.Therefore,the novel zwitterionic sulfobetaine-based monolith was successfully employed for the highly selective separation of small bioactive compounds and the efficient enrichment of N-glycopeptides from complex samples.In this study,we prepared a novel zwitterionic sulfobetaine-based monolith with good performance and developed a simpler and faster method for preparation of zwitterionic monoliths.
基金supported by the National Natural Science Foundation of China(No. 20977052)the Chinese Academy of Sciences(Grant No. KZCX2-YW-420)the National 973 Program(No. 2009CB421606)
文摘In this paper,hierarchically porous Fe2O3 /CuO composite monoliths were first successfully synthesized by a mild method using silica monoliths as templates.The structure of composite monoliths was characterized by X-ray diffraction,scanning electron microscopy,nitrogen adsorption-desorption.The results indicated that the molar ratio of Fe to Cu had a great influence on the crystal phase of Fe2O3,pore size and the structure of the macroporous wall.The Fe2O3 /CuO composite monoliths consist of hierarchically macroporous and mesoporous structure,while the sample with the Fe/Cu molar ratio of 2：1 possesses tighter wall structure than other samples.It is expected that asprepared Fe2O3/CuO composite monoliths have potential applications in several fields as catalysts,catalyst supports,chemical sensors and high-performance liquid chromatography （HPLC）.
基金the National Advanced Materials Committee of China (Grant No. 715-006-0122) and the Ministry of Science and Technology, China (
文摘A new method for preparing LiLaNiO/γ(-Al2O3 monolithic catalyst was described and discussed. The catalyst, which was supported over the monolith, was evaluated in a POM to syngas process. Relative stable catalytic properties during the 120 hours operation at atmospheric pressure were found for the catalyst. Under the high space velocity of 9.0×104l/(kg·（h）（CH4）, the conversion of methane came to 95.5%, and the selectivity of carbon monoxide was not below 96.0% at 1123K when ratio of the feedstock （CH4/O2） was equal to 2.0.
文摘A new route to synthesize ZSM-5 monoliths with hierarchical pore structure has been referred to in this study. The successful incorporation of the macropores and mesopores within the ZSM-5 struc- ture was achieved through transforming the skeleton of the macroporous silica gel into zeolite ZSM-5 using carbon materials as the transitional template. The ZSM-5 crystal covered part of the macroporous material, and provided micropores to the macroporous silica gel. The structure of carbon monolith was studied after dissolving the silica contained in the carbon/silica composite.
文摘Methane adsorption by different forms of activated carbon obtained from coffee husks, including monolith honeycomb and disc types, was studied by activation with zinc salts and potassium hydroxide at 298.15 K and 303.15 K and pressures up to 30.00 atm in a volumetric adsorption apparatus. We observed increased methane adsorption capacity on a mass basis in the different activated carbon monoliths with increasing surface area, total pore volume and micropore volume, with the honeycomb type displaying the highest methane absorption capacity. The maximum volumetric methane uptake by the synthesised carbon monoliths was observed to be 130 V/V at 298.15 K and 30.00 atm for honeycomb monoliths synthesised with zinc chloride (ZnCl2) and Polyvinyl alcohol (PVA) as the binder. Adsorption calorimetry results were used to describe the interaction between vip molecules and the adsorbent at low surface coverage and the energetic heterogeneous surface nature of the adsorbent.
基金Supported by the National Natural Science Foundation of China(52506188,52476215)Natural Science Foundation of Liaoning Province(2024-MS-139,2024JH3/10200047)Scientific Research Program of Department of Education of Liaoning Province(310125042,LJ212410143033。
文摘In this paper,the Ni/Al_(2)O_(3) monolithic catalyst with 15%Ni content was prepared using cordierite as a matrix,and the catalyst was modified with 10%NaOH to study the methanation performance of biomass gasification simulated gas based on alkali-modified Ni/Al_(2)O_(3) monolithic catalyst.BET,TEM,H_(2)-TPR,XRD,CO_(2)-TPD and TG were used to characterize the physicochemical properties of the catalyst before and after modification.The results indicated that the CO conversion rate trends of unmodified and modified Ni/Al_(2)O_(3) monolithic catalysts over 2 h were fundamentally consistent.However,the Ni/Al_(2)O_(3) catalysts modified for 2 h demonstrated significantly enhanced performance compared to those modified for 1 h.Regarding CH4 selectivity,the modified Ni/Al_(2)O_(3) catalyst exhibited markedly better performance than the unmodified Ni/Al_(2)O_(3) catalyst,confirming the enhanced methane performance of the alkali-modified Ni/Al_(2)O_(3) monolithic catalyst.Under optimized conditions(H_(2)/CO volume ratio of 3∶1,space velocity of 10000 mL/(g·h),and temperature of 400℃),the methanation performance of the Ni/Al_(2)O_(3) monolithic catalyst modified for 2 h reached its peak,achieving a CO conversion rate of 97%with 100%CH4 selectivity.
基金This study was supported byÅForsk research grant and Anhui Provincial Natural Science Foundation(No.2108085QB72)。
文摘Utilizing solar energy for sorbent regeneration during the CO_(2)swing adsorption process could potentially reduce CO_(2)capture costs.This study describes a new technique—solar thermal swing adsorption(STSA)for CO_(2)capture based on application of intermittent illumination onto porous carbon monolith(PCM)sorbents during the CO_(2)capture process.This allows CO_(2)to be selectively adsorbed on the sorbents during the light-off periods and thereafter released during the light-on periods due to the solar thermal effect.The freestanding and mechanically strong PCMs have rich ultramicropores with narrow pore size distributions,displaying relatively high CO_(2)adsorption capacity and high CO_(2)/N_(2) selectivity.Given the high CO_(2)capture performance,high solar thermal conversion efficiency,and high thermal conductivity,the PCM sorbents could achieve high CO_(2)capture rate of up to 0.226 kg·kgcarbon^(-1)·h^(-1)from a gas mixture of 20 vol.%CO_(2)/80 vol.%N_(2) under STSA conditions with a light intensity of 1000 W·m^(-2).In addition,the combination of STSA with the conventional vacuum swing adsorption technique further increases the CO_(2)working capacity.
基金supported by the National Natural Science Foundation of China(52272177,12204010)the Foundation for the Introduction of High-Level Talents of Anhui University(S020118002/097)+1 种基金the University Synergy Innovation Program of Anhui Province(GXXT-2023-066)the Scientific Research Project of Anhui Provincial Higher Education Institution(2023AH040008)。
文摘Flexible electronics face critical challenges in achieving monolithic three-dimensional(3D)integration,including material compatibility,structural stability,and scalable fabrication methods.Inspired by the tactile sensing mechanism of the human skin,we have developed a flexible monolithic 3D-integrated tactile sensing system based on a holey MXene paste,where each vertical one-body unit simultaneously functions as a microsupercapacitor and pressure sensor.The in-plane mesopores of MXene significantly improve ion accessibility,mitigate the self-stacking of nanosheets,and allow the holey MXene to multifunctionally act as a sensing material,an active electrode,and a conductive interconnect,thus drastically reducing the interface mismatch and enhancing the mechanical robustness.Furthermore,we fabricate a large-scale device using a blade-coating and stamping method,which demonstrates excellent mechanical flexibility,low-power consumption,rapid response,and stable long-term operation.As a proof-of-concept application,we integrate our sensing array into a smart access control system,leveraging deep learning to accurately identify users based on their unique pressing behaviors.This study provides a promising approach for designing highly integrated,intelligent,and flexible electronic systems for advanced human-computer interactions and personalized electronics.
基金supported by the National Natural Science Foundation of China (Grant Nos.12192251,12334014,62335019,12134001,1230441812474378)+1 种基金the Quantum Science and Technology National Science and Technology Major Project(Grant No.2021ZD0301403)the Shanghai Municipal Science and Technology Major Project (Grant No.2019SHZDZX01)。
文摘Photonic neural networks(PNNs)of sufficiently large physical dimensions and high operation accuracies are envisaged as ideal candidates for breaking the major bottlenecks in the current artificial intelligence architectures in terms of latency,energy efficiency,and computational power.To achieve this vision,it is of vital importance to scale up the PNNs while simultaneously reducing the high demand on the dimensions required by them.The underlying cause of this strategy is the enormous gap between the scales of photonic and electronic integrated circuits.Here,we demonstrate monolithically integrated optical convolutional processors on thin film lithium niobate(TFLN)that harness inherent parallelism in photonics to enable large-scale programmable convolution kernels and,in turn,greatly reduce the dimensions required by subsequent fully connected layers.Experimental validation achieves high classification accuracies of 96%(86%)on the MNIST(Fashion-MNIST)dataset and 84.6%on the AG News dataset while dramatically reducing the required subsequent fully connected layer dimensions to 196×10(from 784×10)and 175×4(from 800×4),respectively.Furthermore,our devices can be driven by commercial field-programmable gate array systems;a unique advantage in addition to their scalable channel number and kernel size.Our architecture provides a solution to build practical machine learning photonic devices.
