Enhance gas-separation efficiency of mixed matrix membranes by lamellarly arranged metal-organic polyhedron

Eliminating the nonselective permeation path inside the mixed-matrix membranes(MMMs)is critical for fabrication of gas separation membranes.We demonstrate that by utilizing the phase separation of block copolymers,we are able to introduce metal-organic polyhedrons(MOPs)with precise pore sizes into a polymer matrix and form an ordered layered structure.We also prove that,by arranging MOP cages into a continuous nanosheet-like layer structure,we are able to generate repeated MOP-effective pathways and deplete the MOP-free permeation pathways,thus enhancing the gas-separation efficiency of MMMs.

Spatiotemporal studies of molecular clusters with neutron scattering methodology

Molecular clusters(MCs)refer to a class of atom collections with sizes ranging from 1 to 10 nms,which are structurally precise and mono-dispersed.Typically,the MC family contains polyoxometalates(POMs),polyhedral oligomeric silsesquioxanes(POSSs),metal-organic poly-hedrons(MOPs),fullerene,metal clusters,etc.

A polymeric co-assembly of subunit vaccine with polyoxometalates induces enhanced immune responses

Long-lasting protective immune responses are expected following vaccination.However,most vaccines alone are inability to evoke an efficient protection.The combinatory administration of adjuvants with vaccines is critical for generating the enhanced immune responses.Herein,with biocompatible poly(4-vinylpyridine)(P4VP)as template,2.5 nm iron/molybdenum oxide cluster,{Mo_(72)Fe_(30)},is applied as an adjuvant to co-assemble with antigens of Mycobacterium bovis via hydrogen bonding at molecular scale.Molecular scale integration of the antigens and{Mo_(72)Fe_(30)}and their full exposure to body fluid media contribute to the augmentation of both humoral and cellular immune responses of the vaccines after inoculation in mice.Anti-inflammatory factor IL-10 gradually increases after 2 weeks followed by a final back to normal level by the 5th week.The balance between proinflammatory cytokines and anti-inflammatory factors suggests that immune system can be activated in the early stage of infection by the antigens carried by the supra-particles and secrete acute inflammatory factors for host defense and anti-inflammatory factors for immune protection.

Wearable membranes from zirconium-oxo clusters cross-linked polymer networks for ultrafast chemical warfare agents decontamination

The urgent need for immediate personal protection against chemical warfare agents(CWAs)spurs the requirement on robust and highly efficient catalytic systems that can be conveniently integrated to wearable devices.Herein,as a new concept for CWA decontamination catalyst design,sub-nanoscale,catalytically active zirconium-oxo molecular clusters are covalently integrated in flexible polymer network as crosslinkers for the full exposure of catalytic sites as well as robust framework structures.The obtained membrane catalysts exhibit high swelling ratio with aqueous content as 84 wt%and therefore,demonstrate quasi-homogeneous catalytic activity toward the rapid hydrolysis of both CWA,soman(GD)(t_(1/2)=5.0 min)and CWA simulant,methyl paraoxon(DMNP)(t_(1/2)=8.9 min).Meanwhile,due to the covalent nature of cross-linkages and the high flexibility of polymer strands,the membranes possess promising mechanical strength and toughness that can stand the impact of high gas pressures and show high permeation for both CO_(2)and O_(2),enabling their extended applications in the field of collective/personal protective materials with body comfort.

Polymerization-induced microphase separation of polymer-polyoxometalate nanocomposites for anhydrous solid state electrolytes

Solid-state electrolytes(SSEs)with high ionic conductivity,mechanical stability,and high thermal stability,as well as the stringent requirement of application in high-temperature fuel cells and lithium-ion batteries is receiving increasing attention.Polymer nanocomposites(PNCs),combining the advantages of inorganic materials with those of polymeric materials,offer numerous opportunities for SSEs design.In this work,we report a facile and general one-pot approach based on polymerization-induced microphase separation(PIMS)to generate PNCs with bi-continuous microphases.This synthetic strategy transforms a homogeneous liquid precursor consisting of polyoxometalates(POMs,H_(3)PW_(12)O_(40),Li_(7)[V_(15)O_(36)(CO_(3))]),poly(ethylene glycol)(PEG)macro-chain-transfer agent,styrene and divinylbenzene monomers,into a robust and transparent monolith.The resulting POMs are uniformly dispersed in the PEG block(PEG/POM)to form a conducting pathway that successfully realizes the effective transfer of protons and lithium ions,while the highly cross-linked polystyrene domains(P(S-co-DVB))as mechanical support provide outstanding mechanical properties and thermal stability.As the POM loading ratio up to 35 wt%,the proton conductivity of nanocomposite reaches as high as 5.99×10^(-4) S/cm at 100℃ in anhydrous environment,which effectively promotes proton transfer under extreme environments.This study broadens the application of fuel cells and lithium-ion batteries in extreme environments.

Unique Ligand Exchange Dynamics of Metal-Organic Polyhedra for Vitrimer-like Gas Separation Membranes

Metal-organic polyhedra(MOPs)possess a microporous framework and impose hierarchical constraints on their surface ligands,leading to the long-ignored,logarithmic ligand exchange dynamics.Herein,polymer networks with MOP as nanoscale cross-linkers(MOP-CNs)can integrate unique ligand exchange dynamics and microporosity,affording vitrimer-like gas separation membranes with promising mechanical performance and(re)processability.All the ligands on the MOP surfaces are confined and correlated via a 3D coordination framework and their neighboring spaces,giving rise to a high energy barrier for ligand exchange.Therefore,MOP-CNs demonstrate high mechanical strengths at room temperature due to their negligible ligand dynamics.The thermo-activated ligand exchange process with integrated network topology enables facile(re)processing and high solvo-resistance at high temperatures.This facilitates Arrhenius type temperature dependence of flowability and stress relaxation,giving rise to the simultaneous achievement of promising mechanical strengths and(re)processability.Finally,the cage topologies of MOPs endow the materials with a bonus microporous feature and spur their applications as gas separation membranes.