Encapsulation and Chemical Resistance of Electrospun Nylon Nanofibers Coated Using Integrated Atomic and Molecular Layer Deposition

Oldham, Christopher J.; Gong, Bin; Spagnola, Joseph C.; Senecal, Kris; Godfrey, Thomas; Parsons, Gregory N.

doi:10.1149/1.3609046

Cited by 41 publications

(54 citation statements)

References 28 publications

(46 reference statements)

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“…35 On the other hand, in the case of poly(propylene) bers, an Al 2 O 3 base layer is employed to deposit ZnO, where the former protects the diffusion of DEZn into the polymer. 36 Apart from these limitations ALD in fact can yield coral, 37 core-shell 38 like complex nanostructures, which are potential materials for photocatalytic applications.…”

Section: Photocatalytic Activity Of Core-shell Heterojunction Nanobersmentioning

confidence: 99%

Selective isolation of the electron or hole in photocatalysis: ZnO–TiO2 and TiO2–ZnO core–shell structured heterojunction nanofibers via electrospinning and atomic layer deposition

et al. 2014

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Heterojunctions are a well-studied material combination in photocatalysis studies, the majority of which aim to improve the efficacy of the catalysts. Developing novel catalysts begs the question of which photo-generated charge carrier is more efficient in the process of catalysis and the associated mechanism. To address this issue we have fabricated core-shell heterojunction (CSHJ) nanofibers from ZnO and TiO 2 in two combinations where only the 'shell' part of the heterojunction is exposed to the environment to participate in the photocatalysis. Core and shell structures were fabricated via electrospinning and atomic layer deposition, respectively which were then subjected to calcination. These CSHJs were characterized and studied for photocatalytic activity (PCA). These two combinations expose electrons or holes selectively to the environment. Under suitable illumination of the ZnO-TiO 2 CSHJ, e/h pairs are created mainly in TiO 2 and the electrons take part in catalysis (i.e. reduce the organic dye) at the conduction band or oxygen vacancy sites of the 'shell', while holes migrate to the core of the structure. Conversely, holes take part in catalysis and electrons diffuse to the core in the case of a TiO 2 -ZnO CSHJ. The results further revealed that the TiO 2 -ZnO CSHJ shows $1.6 times faster PCA when compared to the ZnO-TiO 2 CSHJ because of efficient hole capture by oxygen vacancies, and the lower mobility of holes.

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Section: Photocatalytic Activity Of Core-shell Heterojunction Nanobersmentioning

confidence: 99%

Selective isolation of the electron or hole in photocatalysis: ZnO–TiO2 and TiO2–ZnO core–shell structured heterojunction nanofibers via electrospinning and atomic layer deposition

et al. 2014

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“…In this article, we compare the relative densities of some of the above listed intrinsic defects with reference to the calcination effect and PCA. The catalysts examined here were fabricated via a renounced and industrially applicable combination [10,11,18,28,29,[39][40][41], viz. electrospinning [42][43][44] and atomic layer deposition (ALD) [45][46][47][48][49].…”

Section: Introductionmentioning

confidence: 99%

Transformation of polymer-ZnO core–shell nanofibers into ZnO hollow nanofibers: Intrinsic defect reorganization in ZnO and its influence on the photocatalysis

Kayacı

Vempati

Özgit-Akgün

et al. 2015

Applied Catalysis B: Environmental

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a b s t r a c tPhotocatalytic activity (PCA) on semiconductors is known to be majorly influenced by specific surface area and intrinsic lattice defects of the catalyst. In this report, we tested the efficiencies of 1D ZnO catalysts of varying fiber diameter (80 nm and 650 nm of inner diameter) in two formats, viz. core-shell and hollow nanofibers, where the former is calcined to yield the latter. These nanofibrous catalysts were produced by combining electrospinning and atomic layer deposition processes which were then subjected to thorough characterization including photoluminescence (PL) unveiling the details of intrinsic defects/densities. During the thermal treatment, intrinsic defects are reorganized and as a result a new PL band is observed apart from some significant changes in the intensities of other emissions. The densities of various intrinsic defects from PL are compared for all samples and juxtaposed with the PCA. Careful scrutiny of the various results suggested an anti-correlation between surface area and PCA; i.e., higher surface area does not necessarily imply better PCA. Beyond a limit, the most deterministic factor would be the density of surface defects rather than the specific surface area. The results of this study enable the researchers to fabricate 1D semiconductor photocatalysts while striking the balance between surface area and density of defects.

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“…[1][2][3][4][5][6][7][8][9][10] In fact ALD can yield coral, 6 core-shell, 4,5,11 hollow 6,7,9 like complex nanostructures. Although various polymers are the subjects of electrospinning, the compatibility between the polymer and the ALD precursor is vital.…”

Section: Introductionmentioning

confidence: 99%

“…Although various polymers are the subjects of electrospinning, the compatibility between the polymer and the ALD precursor is vital. 2 The foremost condition is the thermal stability of the polymer as ALD generally takes places at slightly elevated temperatures. The other factor is the chemical compatibility, see the ALD of Al 2 O 3 on nylon-6 polymer, 2 ALD of ZnO on poly(propylene) bers with Al 2 O 3 base layer to inhibit the diffusion of diethylzinc (DEZn) into the polymer.…”

Section: Introductionmentioning

confidence: 99%

Water-soluble non-polymeric electrospun cyclodextrin nanofiber template for the synthesis of metal oxide tubes by atomic layer deposition

et al. 2014

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We report on the suitability of water-soluble non-polymeric electrospun cyclodextrin (CD) nanofiber templates by using atomic layer deposition (ALD) to yield metal oxide tubes. To demonstrate this, watersoluble electrospun CD nanofibers were chosen as template to produce metal oxide tubes where we have tested two examples of ALD coatings, namely, Al 2 O 3 and ZnO. After the ALD coating on the CD nanofibers, the CD core is simply dissolved in water to yield metal oxide tubes. Morphological investigations suggested that Al 2 O 3 is smoother in contrast to ZnO which shows a grainy structure.Structural characterization evidenced amorphous Al 2 O 3 and highly crystalline ZnO. Given the applicability of Al 2 O 3 and ZnO in various contexts the ionic states of Al, Zn and O are also investigated.After the washing step to remove the CD core, Al 2 O 3 developed some hydroxylation, while ZnO hosts various oxygen related functional groups.

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Encapsulation and Chemical Resistance of Electrospun Nylon Nanofibers Coated Using Integrated Atomic and Molecular Layer Deposition

Cited by 41 publications

References 28 publications

Selective isolation of the electron or hole in photocatalysis: ZnO–TiO2 and TiO2–ZnO core–shell structured heterojunction nanofibers via electrospinning and atomic layer deposition

Selective isolation of the electron or hole in photocatalysis: ZnO–TiO2 and TiO2–ZnO core–shell structured heterojunction nanofibers via electrospinning and atomic layer deposition

Transformation of polymer-ZnO core–shell nanofibers into ZnO hollow nanofibers: Intrinsic defect reorganization in ZnO and its influence on the photocatalysis

Water-soluble non-polymeric electrospun cyclodextrin nanofiber template for the synthesis of metal oxide tubes by atomic layer deposition

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