Three-dimensional Porous Metal Research Articles

A Novel Chiral Doubly Folded Interpenetrating 3D Metal−Organic Framework Based on the Flexible Zwitterionic Ligand

A novel chiral 2-fold interpenetrating three-dimensional (3D) porous metal−organic framework (MOF), [PbCl(C7H7N2O4)] (1), has been constructed from the flexible zwitterionic ligand N,N‘-diacetic acid imidazolium chloride and Pb(NO3)2. The 3D MOF possesses right-handed helical rectangular channels with 41 helices running along the c-axis. Compound 1 represents the first even number-fold interpenetrating 3D chiral MOF constructed from a symmetrical flexible ligand without any chiral auxiliary.

Synthesis, structure, and adsorption properties of a three-dimensional porous yttrium–organic coordination network

Deprotonation of 4,4′-biphenyldicarboxylic acid (H 2BPDC) with triethylamine followed by the copolymerization with Y(III) in N,N-dimethylformamide (DMF) at room temperature yields a new three-dimensional (3-D) porous metal–organic coordination network, [Y 2(BPDC) 3(DMF) 2(H 2O) 2] n · (DMF) n · (H 2O) n ( 1). Compound 1 (C 24.50H 19N 1.50O 9Y) crystallizes in the triclinic P-1 space group ( a = 8.220 (2), b = 13.998 (4), c = 14.212 (4) Å, α = 111.058 (5)°, β = 90.187 (5)°, γ = 94.318 (5)°, V = 1520.9 (7) Å 3, and Z = 2). X-ray crystallography reveals that 1 consists of a 3-D framework contained open 1-D channels with the dimension of 5 × 10 Å along the crystallographic a axis. The adsorption measurements show that compound 1 can adsorb N 2, Ar and CO 2 into its pores. The adsorption isotherms for MeOH and H 2O were also measured.

A three-dimensional porous metal–organic framework with the rutile topology constructed from triangular and distorted octahedral building blocks

The solvothermal reaction of zinc acetate dihydrate with 1,3,5-benzenetricarboxylic acid yields a three-dimensional porous metal-organic framework constructed from triangular and distorted octahedral building blocks, the framework of which can be described as a decorated rutile net.

Linearized turbulent lubrication equation for finite self-acting porous bearings considering slip velocity over a hydrodynamically rough permeable boundary

A first attempt to derive a new lubrication equation for the hydrodynamic pressure generation in a three-dimensional self-acting porous metal bearing operating in a turbulent regime (fully developed) with single-phase Newtonian incompressible lubricant is presented considering simultaneously the slip velocity and the hydrodynamically rough permeable surface (in terms of the median diameter of the graded constituent particles of the sintered porous matrix and their standard deviation) with a hydrodynamically rough rotor. The analysis is analogous to boundary layer theory wherein the lubricant motion is treated as a generalized turbulent channel flow in which the rough porous wall is stationary and the impervious wall (also considered rough) is in longitudinal motion so that the flow is a turbulent shear flow coupled with codirectional and transverse turbulent pressure flow. A linearization or perturbation technique is used to decouple the two orthogonal turbulent flows by assuming that the turbulent shear stress in a finite bearing is a small perturbation of the shear stress for turbulent couette flow. Using Boussinesq's eddy viscosity formulation and the experimentally established logarithmic law as the universal law of wall, the governing pressure distribution equation is obtained from consideration of the conservation of momentum and continuity. The whole treatment is approached from the point of view of fluid film design. No ad hoc slip model is used, and the lubrication equation is fully analytical and can be applied to a number of particular bearing problems by applying suitable simplifying restrictive conditions. The derived lubrication equation can be used to predict bearing performance characteristics even in situations where the bearing permeability is non-isotropic.