1
|
Jara Fornerod M, Alvarez-Fernandez A, Williams ER, Skoda MWA, Prieto-Simon B, Voelcker NH, Stefik M, Coppens MO, Guldin S. Enhanced Structural Control of Soft-Templated Mesoporous Inorganic Thin Films by Inert Processing Conditions. ACS APPLIED MATERIALS & INTERFACES 2022; 14:56143-56155. [PMID: 36503231 PMCID: PMC9782354 DOI: 10.1021/acsami.2c18090] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 11/28/2022] [Indexed: 06/17/2023]
Abstract
Mesoporous thin films are widely used for applications in need of high surface area and efficient mass and charge transport properties. A well-established fabrication process involves the supramolecular assembly of organic molecules (e.g., block copolymers and surfactants) with inorganic materials obtained by sol-gel chemistry. Typically, subsequent calcination in air removes the organic template and reveals the porous inorganic network. A significant challenge for such coatings is the anisotropic shrinkage due to the volume contraction related to solvent evaporation, inorganic condensation, and template removal, affecting the final porosity as well as pore shape, size, arrangement, and accessibility. Here, we show that a two-step calcination process, composed of high-temperature treatment in argon followed by air calcination, is an effective fabrication strategy to reduce film contraction and enhance structural control of mesoporous thin films. Crucially, the formation of a transient carbonaceous scaffold enables the inorganic matrix to fully condense before template removal. The resulting mesoporous films retain a higher porosity as well as bigger pores with extended porous order. Such films present favorable characteristics for mass transport of large molecules. This is demonstrated for lysozyme adsorption into the mesoporous thin films as an example of enzyme storage.
Collapse
Affiliation(s)
| | - Alberto Alvarez-Fernandez
- Department
of Chemical Engineering, University College
London, Torrington Place, London WC1E 7JE, U.K.
| | - Eric R. Williams
- Department
of Chemistry and Biochemistry, University
of South Carolina, Columbia, South Carolina 29208, United States
| | - Maximilian W. A. Skoda
- ISIS
Pulsed Neutron and Muon Source, Rutherford
Appleton Laboratory, Harwell, Oxfordshire OX11 OQX, U.K.
| | - Beatriz Prieto-Simon
- Department
of Electronic Engineering, Universitat Rovira
i Virgili, 43007 Tarragona, Spain
- ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Spain
| | - Nicolas H. Voelcker
- Monash Institute
of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
- Melbourne
Centre for Nanofabrication, Victorian Node
of the Australian National Fabrication Facility, Clayton, Victoria 3168, Australia
| | - Morgan Stefik
- Department
of Chemistry and Biochemistry, University
of South Carolina, Columbia, South Carolina 29208, United States
| | - Marc-Olivier Coppens
- Department
of Chemical Engineering, University College
London, Torrington Place, London WC1E 7JE, U.K.
- Centre
for Nature Inspired Engineering, University
College London, Torrington
Place, London WC1E 7JE, U.K.
| | - Stefan Guldin
- Department
of Chemical Engineering, University College
London, Torrington Place, London WC1E 7JE, U.K.
| |
Collapse
|
2
|
Ye Z, Zhao L, Nikiforov A, Giraudon JM, Chen Y, Wang J, Tu X. A review of the advances in catalyst modification using nonthermal plasma: Process, Mechanism and Applications. Adv Colloid Interface Sci 2022; 308:102755. [PMID: 36030562 DOI: 10.1016/j.cis.2022.102755] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 05/05/2022] [Accepted: 08/10/2022] [Indexed: 11/18/2022]
Abstract
With the continuous development of catalytic processes in chemistry, biology, organic synthesis, energy generation and many other fields, the design of catalysts with novel properties has become a new paradigm in both science and industry. Nonthermal plasma has aroused extensive interest in the synthesis and modification of catalysts. An increasing number of researchers are using plasma for the modification of target catalysts, such as modifying the dispersion of active sites, regulating electronic properties, enhancing metal-support interactions, and changing the morphology. Plasma provides an alternative choice for catalysts in the modification process of oxidation, reduction, etching, coating, and doping and is especially helpful for unfavourable thermodynamic processes or heat-sensitive reactions. This review focuses on the following points: (i) the fundamentals behind the nonthermal plasma modification of catalysts; (ii) the latest research progress on the application of plasma modified catalysts; and (iii) main challenges in the field and a vision for future development.
Collapse
Affiliation(s)
- Zhiping Ye
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China; State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing 100084, China; Department of Chemical Engineering, Sichuan University, Chengdu 610065, Sichuan, China
| | - Liang Zhao
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Anton Nikiforov
- Department of Applied Physics, Research Unit Plasma Technology Ghent University, Ghent 9000, Belgium
| | - Jean-Marc Giraudon
- Univ. Lille, CNRS, Centrale Lille, ENSCL, Univ. Artois, Lille F-59000, France
| | - Yue Chen
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jiade Wang
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China.
| | - Xin Tu
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool L69 3GJ, UK.
| |
Collapse
|
3
|
Alvarez-Fernandez A, Fornerod MJ, Reid B, Guldin S. Solvent Vapor Annealing for Controlled Pore Expansion of Block Copolymer-Assembled Inorganic Mesoporous Films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:3297-3304. [PMID: 35235337 PMCID: PMC9097528 DOI: 10.1021/acs.langmuir.2c00074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 02/23/2022] [Indexed: 05/18/2023]
Abstract
Mesoporous inorganic thin films are promising materials architectures for a variety of high-value applications, ranging from optical coatings and purification membranes to sensing and energy storage devices. Having precise control over the structural parameters of the porous network is crucial for broadening their applicability. To this end, the use of block copolymers (BCP) as sacrificial structure-directing agents via micelle coassembly is a particularly attractive route, since the resultant pore size is directly related to scaling laws for the radius of gyration of the pore-forming macromolecule. However, tailoring the molecular weight of the BCP via bespoke synthesis is an elaborate process that requires precise control over highly sensitive reactions conditions. Alternative methods have emerged, based on supramolecular assembly or the addition of different swelling agents. Nevertheleses, to date, these present a negative impact on the structural order and pore size dispersity of the final inorganic mesoporous films. In this work, we propose a novel and effective method for control over pore size, porosity, and structural order, which relies on a synergistic combination of BCP selective swelling via solvent vapor annealing (SVA) and locking of the structure by condensation of the inorganic sol-gel precursors. The results obtained in this work for TiO2 establish SVA as a new, straightforward, simple, and powerful route for the fabrication of mesoporous thin-film materials with controllable structural characteristics.
Collapse
|
4
|
Alvarez S, Marcasuzaa P, Billon L. Bio-Inspired Silica Films Combining Block Copolymers Self-Assembly and Soft Chemistry: Paving the Way toward Artificial Exosqueleton of Seawater Diatoms. Macromol Rapid Commun 2020; 42:e2000582. [PMID: 33274818 DOI: 10.1002/marc.202000582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 11/06/2020] [Indexed: 11/09/2022]
Abstract
This review is in line with the principles of bio-inspiration and biomimicry in order to envisage a softer and more environmentally friendly chemistry. Here, the source of inspiration is a microalga from the oceans with the ability to build an exoskeleton of silica under ambient conditions. Following this model, this review is interested in different ways of creating porous silica films with a hierarchical porosity similar to diatoms. For this purpose, polymeric/hybrid/inorganic films structured in honeycomb using the breath figure method are reported. This versatile and easy to implement method based on the principle of rapid evaporation of a solvent in a humid atmosphere is widely used in the formation of structured films with micron-sized pores. In addition to this, the self-assembly of copolymer at the nanoscale can be addressed to obtain a hierarchically structured film. Following this structuration step, the degradation of a sacrificial block is then described from the most energy-intensive to soft process, allowing an added nanoporosity to the micron porosity of the BF method. Finally, hierarchical porous silica films are described using the sol-gel process, which is known as a soft chemistry process.
Collapse
Affiliation(s)
- Sandra Alvarez
- Universite de Pau et Pays de l'Adour, E2S UPPA, CNRS, Institut des Sciences Analytiques & de PhysicoChimie pour l'Environnement & les Matériaux, UMR5254, 2 avenue du Président Angot, Pau, F-64053, France.,Bio-Inspired Materials Group: Functionalities and Self-Assembly, E2S UPPA, IPREM UMR 5254, 2 avenue du Président Angot, Pau, F-64053, France
| | - Pierre Marcasuzaa
- Universite de Pau et Pays de l'Adour, E2S UPPA, CNRS, Institut des Sciences Analytiques & de PhysicoChimie pour l'Environnement & les Matériaux, UMR5254, 2 avenue du Président Angot, Pau, F-64053, France.,Bio-Inspired Materials Group: Functionalities and Self-Assembly, E2S UPPA, IPREM UMR 5254, 2 avenue du Président Angot, Pau, F-64053, France
| | - Laurent Billon
- Universite de Pau et Pays de l'Adour, E2S UPPA, CNRS, Institut des Sciences Analytiques & de PhysicoChimie pour l'Environnement & les Matériaux, UMR5254, 2 avenue du Président Angot, Pau, F-64053, France.,Bio-Inspired Materials Group: Functionalities and Self-Assembly, E2S UPPA, IPREM UMR 5254, 2 avenue du Président Angot, Pau, F-64053, France
| |
Collapse
|
5
|
Alvarez-Fernandez A, Reid B, Suthar J, Choy SY, Jara Fornerod M, Mac Fhionnlaoich N, Yang L, Schmidt-Hansberg B, Guldin S. Fractionation of block copolymers for pore size control and reduced dispersity in mesoporous inorganic thin films. NANOSCALE 2020; 12:18455-18462. [PMID: 32941587 DOI: 10.1039/d0nr05132b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Mesoporous inorganic thin films are promising materials architectures for a variety of applications, including sensing, catalysis, protective coatings, energy generation and storage. In many cases, precise control over a bicontinuous porous network on the 10 nm length scale is crucial for their operation. A particularly promising route for structure formation utilizes block copolymer (BCP) micelles in solution as sacrificial structure-directing agents for the co-assembly of inorganic precursors. This method offers pore size control via the molecular weight of the pore forming block and is compatible with a broad materials library. On the other hand, the molecular weight dependence impedes continuous pore tuning and the intrinsic polymer dispersity presents challenges to the pore size homogeneity. To this end, we demonstrate how chromatographic fractionation of BCPs provides a powerful method to control the pore size and dispersity of the resulting mesoporous thin films. We apply a semi-preparative size exclusion chromatographic fractionation to a polydisperse poly(isobutylene)-block-poly(ethylene oxide) (PIB-b-PEO) BCP obtained from scaled-up synthesis. The isolation of BCP fractions with distinct molecular weight and narrowed dispersity allowed us to not only tune the characteristic pore size from 9.1 ± 1.5 to 14.1 ± 2.1 nm with the identical BCP source material, but also significantly reduce the pore size dispersity compared to the non-fractionated BCP. Our findings offer a route to obtain a library of monodisperse BCPs from a polydisperse feedstock and provide important insights on the direct relationship between macromolecular characteristics and the resulting structure-directed mesopores, in particular related to dispersity.
Collapse
Affiliation(s)
- Alberto Alvarez-Fernandez
- Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, UK.
| | - Barry Reid
- Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, UK.
| | - Jugal Suthar
- Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, UK. and UCL School of Pharmacy, University College London, 29-39 Brunswick Square, Bloomsbury, London, WC1N 1AX, UK
| | - Swan Yia Choy
- Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, UK.
| | - Maximiliano Jara Fornerod
- Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, UK.
| | - Niamh Mac Fhionnlaoich
- Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, UK.
| | - Lixu Yang
- Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, UK.
| | - Benjamin Schmidt-Hansberg
- BASF SE, Process Research & Chemical Engineering, Coating & Film Processing, Carl-Bosch-Strasse 38, 67056 Ludwigshafen am Rhein, Germany
| | - Stefan Guldin
- Department of Chemical Engineering, University College London, Torrington Place, London, WC1E 7JE, UK.
| |
Collapse
|
6
|
Alvarez-Fernandez A, Reid B, Fornerod MJ, Taylor A, Divitini G, Guldin S. Structural Characterization of Mesoporous Thin Film Architectures: A Tutorial Overview. ACS APPLIED MATERIALS & INTERFACES 2020; 12:5195-5208. [PMID: 31961128 DOI: 10.1021/acsami.9b17899] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Mesoporous thin film architectures are an important class of materials that exhibit unique properties, which include high surface area, versatile surface functionalization, and bicontinuous percolation paths through a broad library of pore arrangements on the 10 nm length scale. Although porosimetry of bulk materials via sorption techniques is common practice, the characterization of thin mesoporous films with small sample volumes remains a challenge. A range of techniques are geared toward providing information over pore morphology, pore size distribution, surface area and overall porosity, but none of them offers a holistic evaluation and results are at times inconsistent. In this work, we present a tutorial overview for the reliable structural characterization of mesoporous films. Three model samples with variable pore size and porosity prepared by block copolymer (BCP) coassembly serve for a rational comparison. Various techniques are assessed side-by-side, including scanning electron microscopy (SEM), atomic force microscopy (AFM), grazing incidence small-angle X-ray scattering (GISAXS), and ellipsometric porosimetry (EP). We critically discuss advantages and limitations of each technique and provide guidelines for reliable implementation.
Collapse
Affiliation(s)
- Alberto Alvarez-Fernandez
- Department of Chemical Engineering , University College London , Torrington Place , London WC1E 7JE , United Kingdom
| | - Barry Reid
- Department of Chemical Engineering , University College London , Torrington Place , London WC1E 7JE , United Kingdom
| | - Maximiliano J Fornerod
- Department of Chemical Engineering , University College London , Torrington Place , London WC1E 7JE , United Kingdom
| | - Alaric Taylor
- Department of Chemical Engineering , University College London , Torrington Place , London WC1E 7JE , United Kingdom
| | - Giorgio Divitini
- Department of Materials Science and Metallurgy , University of Cambridge , 27 Charles Babbage Road , Cambridge CB3 0FS , United Kingdom
| | - Stefan Guldin
- Department of Chemical Engineering , University College London , Torrington Place , London WC1E 7JE , United Kingdom
| |
Collapse
|
7
|
Reid B, Alvarez-Fernandez A, Schmidt-Hansberg B, Guldin S. Tuning Pore Dimensions of Mesoporous Inorganic Films by Homopolymer Swelling. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:14074-14082. [PMID: 31577151 DOI: 10.1021/acs.langmuir.9b03059] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The functionality and applications of mesoporous inorganic films are closely linked to their mesopore dimensions. For material architectures derived from a block copolymer (BCP) micelle coassembly, the pore size is typically manipulated by changing the molecular weight corresponding to the pore-forming block. However, bespoke BCP synthesis is often a costly and time-consuming process. An alternative method for pore size tuning involves the use of swelling agents, such as homopolymers (HPs), which selectively interact with the core-forming block to increase the micelle size in solution. In this work, poly(isobutylene)-block-poly(ethylene oxide) micelles were swollen with poly(isobutylene) HP in solution and coassembled with aluminosilicate sol with the aim of increasing the resulting pore dimensions. An analytical approach implementing spectroscopic ellipsometry (SE) and ellipsometric porosimetry (EP) alongside atomic force microscopy (AFM) and small-angle X-ray scattering (SAXS) in transmission and grazing-incidence (GISAXS) modes enabled us to study the material evolution from solution processing through the manifestation of the mesoporous inorganic film after BCP removal. The in-depth SE/EP analysis evidenced an increase of more than 45% in mesopore diameter with HP swelling and a consistent scaling of the overall void volume and number of pores. Importantly, our analytical toolbox enabled us to study the effect of swelling on the connecting necks between adjacent pores, with observed increases as high as ≈35%, offering novel pathways to sensing, electrochemical, and other mass-transfer-dependent applications.
Collapse
Affiliation(s)
- Barry Reid
- Department of Chemical Engineering , University College London , Torrington Place , London WC1E 7JE , U.K
| | - Alberto Alvarez-Fernandez
- Department of Chemical Engineering , University College London , Torrington Place , London WC1E 7JE , U.K
| | - Benjamin Schmidt-Hansberg
- BASF SE, Process Research & Chemical Engineering, Coating & Film Processing , Carl-Bosch-Strasse 38 , 67056 Ludwigshafen am Rhein , Germany
| | - Stefan Guldin
- Department of Chemical Engineering , University College London , Torrington Place , London WC1E 7JE , U.K
| |
Collapse
|