Thermodynamic and sorption behavior of U(VI) and Th(IV) on unsaturated polyester–styrene polymeric beads

B. El-Gammal; G. M. Ibrahim; H. H. El-Nahas

doi:10.1002/app.23307

A Pseudo Five-Fold Symmetrical Ligand Drives Geometric Frustration in Porous Metal-Organic and Hydrogen Bonded Frameworks

10.26434/chemrxiv.12098142.v1 ◽

2020 ◽

Author(s):

Frederik Haase ◽

Gavin Craig ◽

Mickaele Bonneau ◽

kunihisa sugimoto ◽

Shuhei Furukawa

Keyword(s):

Topological Defects ◽

Porous Metal ◽

Building Blocks ◽

Structural Features ◽

Equilibrium Structure ◽

Sorption Behavior ◽

Building Unit ◽

Geometric Frustration ◽

Secondary Building Units ◽

Hydrogen Bonded

Reticular framework materials thrive on designability, but unexpected reaction outcomes are crucial in exploring new structures and functionalities. By combining “incompatible” building blocks, we employed geometric frustration in reticular materials leading to emergent structural features. The combination of a pseudo C5 symmetrical organic building unit based on a pyrrole core, with a C4 symmetrical copper paddlewheel synthon led to three distinct frameworks by tuning the synthetic conditions. The frameworks show structural features typical for geometric frustration: self-limiting assembly, internally stressed equilibrium structures and topological defects in the equilibrium structure, which manifested in the formation of a hydrogen bonded framework, distorted and broken secondary building units and dangling functional groups, respectively. The influence of geometric frustration on the CO2 sorption behavior and the discovery of a new secondary building unit shows geometric frustration can serve as a strategy to obtain highly complex porous frameworks.

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A Pseudo Five-Fold Symmetrical Ligand Drives Geometric Frustration in Porous Metal-Organic and Hydrogen Bonded Frameworks

10.26434/chemrxiv.12098142 ◽

2020 ◽

Author(s):

Frederik Haase ◽

Gavin Craig ◽

Mickaele Bonneau ◽

kunihisa sugimoto ◽

Shuhei Furukawa

Keyword(s):

Topological Defects ◽

Porous Metal ◽

Building Blocks ◽

Structural Features ◽

Equilibrium Structure ◽

Sorption Behavior ◽

Building Unit ◽

Geometric Frustration ◽

Secondary Building Units ◽

Hydrogen Bonded

Reticular framework materials thrive on designability, but unexpected reaction outcomes are crucial in exploring new structures and functionalities. By combining “incompatible” building blocks, we employed geometric frustration in reticular materials leading to emergent structural features. The combination of a pseudo C5 symmetrical organic building unit based on a pyrrole core, with a C4 symmetrical copper paddlewheel synthon led to three distinct frameworks by tuning the synthetic conditions. The frameworks show structural features typical for geometric frustration: self-limiting assembly, internally stressed equilibrium structures and topological defects in the equilibrium structure, which manifested in the formation of a hydrogen bonded framework, distorted and broken secondary building units and dangling functional groups, respectively. The influence of geometric frustration on the CO2 sorption behavior and the discovery of a new secondary building unit shows geometric frustration can serve as a strategy to obtain highly complex porous frameworks.

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A Study of Some Mechanical and Physical Properties for Palm Fiber/Polyester Composite

Engineering and Technology Journal ◽

10.30684/etj.v38i3b.598 ◽

2020 ◽

Vol 38 (3B) ◽

pp. 104-114

Author(s):

Samah M. Hussein

Keyword(s):

Mechanical Properties ◽

Thermal Conductivity ◽

Dielectric Constant ◽

Date Palm ◽

Volume Fraction ◽

Unsaturated Polyester ◽

Dielectric Strength ◽

Palm Fiber ◽

Mechanical And Physical Properties ◽

Polyester Composite

This research has been done by reinforcing the matrix (unsaturated polyester) resin with natural material (date palm fiber (DPF)). The fibers were exposure to alkali treatment before reinforcement. The samples have been prepared by using hand lay-up technique with fiber volume fraction of (10%, 20% and 30%). After preparation of the mechanical and physical properties have been studied such as, compression, flexural, impact strength, thermal conductivity, Dielectric constant and dielectric strength. The polyester composite reinforced with date palm fiber at volume fraction (10% and 20%) has good mechanical properties rather than pure unsaturated polyester material, while the composite reinforced with 30% Vf present poor mechanical properties. Thermal conductivity results indicated insulator composite behavior. The effect of present fiber polar group induces of decreasing in dielectric strength, and increasing dielectric constant. The reinforcement composite 20% Vf showed the best results in mechanical, thermal and electrical properties.

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