A study of the curing behavior of polyamic acid coated on a Cu or Zn layer

Dong, Wenguo; Kim, Gun-Hong; Choi, Jae-Youn; Yoon, Junro; Kim, Young‐Ho

doi:10.1016/j.colsurfa.2008.04.026

Cited by 16 publications

(7 citation statements)

References 23 publications

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“…For MMMs containing ZIF-8 to perform stably and to recover an original gas separation performance of PI, the deimidized PI (i.e., PAA) needs to be imidized. Nevertheless, the very stable coordination bond between zinc cations and carboxylate anions is expected to hamper complete imidization . Previous studies , showed that Zn ion-coordinated polymer (PAA-Zn), in particular, exhibited a lower DI (Equation ) than PAA as well as PAAs coordinated with other metal ions.…”

Section: Resultsmentioning

confidence: 99%

“…Nevertheless, the very stable coordination bond between zinc cations and carboxylate anions is expected to hamper complete imidization . Previous studies , showed that Zn ion-coordinated polymer (PAA-Zn), in particular, exhibited a lower DI (Equation ) than PAA as well as PAAs coordinated with other metal ions. Kim et al found that a relatively high imidization temperature (≥250 °C) was required in order to disengage coordinated Zn ions from chelate complexes and to form imide groups.…”

Section: Resultsmentioning

confidence: 99%

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Highly Propylene-Selective Mixed-Matrix Membranes by in Situ Metal–Organic Framework Formation Using a Polymer-Modification Strategy

Park

Hamid

Jeong

2019

ACS Appl. Mater. Interfaces

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Despite the potential of C 3 H 6 /C 3 H 8 separation, there have been no industrial applications of zeolitic-imidazole framework-8 (ZIF-8) mixed-matrix membranes (MMMs) because of the moderate separation performances and several challenging processing issues. Herein, we present a new paradigm of MMM fabrication, named polymer-modification-enabled in situ metal−organic framework formation (PMMOF), enabling in situ formation of ZIF-8 fillers inside the 4,4-(hexafluoroisopropylidene)diphthalic anhydride 2,4,6-trimethyl-1,3phenylenediamine polymer. PMMOF consists of four steps including hydrolysis of a polymer, ion-exchange, ligand treatment, and imidization. Each step was thoroughly analyzed and important processing parameters were identified, enabling the structural control of MMMs by PMMOF. The binary C 3 H 6 /C 3 H 8 separation performance of the MMMs showed much higher separation factors than conventionally prepared MMMs at similar filler loadings, satisfying the commercial C 3 H 6 /C 3 H 8 separation performance criteria. PMMOF was successfully applied for other MOFs, demonstrating that the process could be general. Finally, as a proof of concept, asymmetric mixed-matrix hollow fiber membranes (i.d. of 0.45 mm and o.d. of 0.63 mm) with ultrathin selective skin layers were prepared by PMMOF, showing C 3 H 6 permeance of 2.17 GPU and C 3 H 6 /C 3 H 8 separation factor of ∼20.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Highly Propylene-Selective Mixed-Matrix Membranes by in Situ Metal–Organic Framework Formation Using a Polymer-Modification Strategy

Park

Hamid

Jeong

2019

ACS Appl. Mater. Interfaces

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“…Because the distance between chains of 6FDA-ODA PI are far greater than that of BPDA-PDA PI, it is more difficult for Cu atoms rejected from the 6FDA-ODA PAA-Cu complex to diffuse and grow as bigger particles. Also, each PI has a different imidization rate, which may affect the formation of nanoparticles [39,40].…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Cu or Cu₂O-polyimide nanocomposites using Cu powders and their optical properties

et al. 2014

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Nanocomposites consisting of Cu or Cu2O nanoparticles in various polyimide (PI) films were successfully prepared using polyamic acid (PAA) and Cu powders. Cu powders were dissolved into PAA solutions, and the solutions were spin-coated onto the substrates. Cu or Cu2O nanoparticles were formed in PI film by curing in a reducing or inert atmosphere, respectively. The Cu nanoparticles were transformed to Cu2O nanoparticles by post-heat treatment in an oxidizing atmosphere after curing in a reducing atmosphere. Transmission electron microscopy showed that uniform, round Cu2O nanoparticles 6.0 nm in diameter were dispersed in the PI film by post-heat treatment. The addition of Cu2O nanoparticles in the 4,4'-(hexafluoroisopropylidene)diphthalic anhydride-4,4'-oxydianiline (6FDA-ODA) PI film enhanced the refractive index of the 6FDA-ODA PI film from 1.60 to 1.72 at 633 nm, and the transparency of the nanocomposite film was about 70-90% in the visible region and remained around 90% beyond 550 nm.

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“…Different nano-metal oxides have been of great interest in recent years due to their catalytic, thermal, mechanical, optical and biomedical applications [30][31][32]. Various ZnO nanostructures, such as nanoparticles, nanorods, nanowires, nanobelts, nanotubes, nanobridges and nanonails, nanowalls, nanohelixes and polyhedral cages have been synthesized and characterized in recent years [33][34][35][36].…”

Section: Page 3 Of 22mentioning

confidence: 99%

ZnO nanorods: Efficient and reusable catalysts for the synthesis of substituted imidazoles in water

Nikoofar

Haghighi

Lashanizadegan

et al. 2015

Journal of Taibah University for Science

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Please cite this article as: K. Nikoofar, M. Haghighi, M. Lashanizadegan, Z. Ahmadvand, ZnO nanorodes: efficient and reusable catalyst for the synthesis of substituted imidazoles in water media, Journal of Taibah University for Science (2015), http://dx. Abstract:A simple procedure has been represented for the synthesis of ZnO nanorodes (ZnO NRs). The characterization of newly synthesized crystals were studied by X-ray diffraction pattern (XRD), fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) techniques. Moreover the catalytic activity has been examined in a one-pot, three component synthesis of 2,4,5-triaryl-1H-imidazoles in water under reflux conditions. The results confirmed ZnO NRs to be a mild, benign and effective catalyst for the trisubstituted imidazoles preparation in high yield via an operationally simple and environmentally-friendly procedure. Furthermore, the catalyst can be recovered conveniently and reused for at least three runs without any activity loss.

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A study of the curing behavior of polyamic acid coated on a Cu or Zn layer

Cited by 16 publications

References 23 publications

Highly Propylene-Selective Mixed-Matrix Membranes by in Situ Metal–Organic Framework Formation Using a Polymer-Modification Strategy

Highly Propylene-Selective Mixed-Matrix Membranes by in Situ Metal–Organic Framework Formation Using a Polymer-Modification Strategy

Synthesis of Cu or Cu₂O-polyimide nanocomposites using Cu powders and their optical properties

ZnO nanorods: Efficient and reusable catalysts for the synthesis of substituted imidazoles in water

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A study of the curing behavior of polyamic acid coated on a Cu or Zn layer

Cited by 16 publications

References 23 publications

Highly Propylene-Selective Mixed-Matrix Membranes by in Situ Metal–Organic Framework Formation Using a Polymer-Modification Strategy

Highly Propylene-Selective Mixed-Matrix Membranes by in Situ Metal–Organic Framework Formation Using a Polymer-Modification Strategy

Synthesis of Cu or Cu2O-polyimide nanocomposites using Cu powders and their optical properties

ZnO nanorods: Efficient and reusable catalysts for the synthesis of substituted imidazoles in water

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Synthesis of Cu or Cu₂O-polyimide nanocomposites using Cu powders and their optical properties