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Shao J, Feng P, Li B, Gao J, Chen Y, Dong M, Qin Z, Fan W, Wang J. The Effect of Water Co-Feeding on the Catalytic Performance of Zn/HZSM-5 in Ethylene Aromatization Reactions. Int J Mol Sci 2024; 25:2387. [PMID: 38397065 PMCID: PMC10888543 DOI: 10.3390/ijms25042387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 02/14/2024] [Accepted: 02/15/2024] [Indexed: 02/25/2024] Open
Abstract
During the methanol-to-aromatics (MTA) process, a large amount of water is generated, while the influence and mechanism of water on the activity and selectivity of the light olefin aromatization reaction are still unclear. Therefore, a study was conducted to systematically investigate the effects of water on the reactivity and the product distribution in ethylene aromatization using infrared spectroscopy (IR), intelligent gravitation analyzer (IGA), and X-ray absorption fine structure (XAFS) characterizations. The results demonstrated that the presence of water reduced ethylene conversion and aromatic selectivity while increasing hydrogen selectivity at the same contact time. This indicated that water had an effect on the reaction pathway by promoting the dehydrogenation reaction and suppressing the hydrogen transfer reaction. A detailed analysis using linear combination fitting (LCF) of Zn K-edge X-ray absorption near-edge spectroscopy (XANES) on Zn/HZSM-5 catalysts showed significant variations in the state of existence and the distribution of Zn species on the deactivated catalysts, depending on different reaction atmospheres and water contents. The presence of water strongly hindered the conversion of ZnOH+ species, which served as the active centers for the dehydrogenation reaction, to ZnO on the catalyst. As a result, the dehydrogenation activity remained high in the presence of water. This study using IR and IGA techniques revealed that water on the Zn/HZSM-5 catalyst inhibited the adsorption of ethylene on the zeolite, resulting in a noticeable decrease in ethylene conversion and a decrease in aromatic selectivity. These findings contribute to a deeper understanding of the aromatization reaction process and provide data support for the design of efficient aromatization catalysts.
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Affiliation(s)
- Jiabei Shao
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, P.O. Box 165, Taiyuan 030001, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Pengcheng Feng
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, P.O. Box 165, Taiyuan 030001, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Baichao Li
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, P.O. Box 165, Taiyuan 030001, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jie Gao
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, P.O. Box 165, Taiyuan 030001, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yanyan Chen
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, P.O. Box 165, Taiyuan 030001, China
| | - Mei Dong
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, P.O. Box 165, Taiyuan 030001, China
| | - Zhangfeng Qin
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, P.O. Box 165, Taiyuan 030001, China
| | - Weibin Fan
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, P.O. Box 165, Taiyuan 030001, China
| | - Jianguo Wang
- University of Chinese Academy of Sciences, Beijing 100049, China
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Geng R, Liu Y, Guo Y, Wang P, Dong M, Wang S, Wang J, Qin Z, Fan W. Structure Evolution of Zn Species on Fresh, Deactivated, and Regenerated Zn/ZSM-5 Catalysts in Ethylene Aromatization. ACS Catal 2022. [DOI: 10.1021/acscatal.2c04074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Rui Geng
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yacong Liu
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yanxia Guo
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Pengfei Wang
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mei Dong
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001, China
| | - Sen Wang
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001, China
| | - Jianguo Wang
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhangfeng Qin
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001, China
| | - Weibin Fan
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001, China
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Geng R, Liu Y, Gao J, Guo Y, Dong M, Wang S, Fan W, Wang J, Qin Z. The migration of Zn species on Zn/ZSM-5 catalyst during the process of ethylene aromatization. Catal Sci Technol 2022. [DOI: 10.1039/d2cy00661h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The Zn species in the Zn/ZSM-5 catalyst undergo reciprocal transformation of ZnO clusters and ZnOH+ during the ethylene aromatization process. They then migrate to form large-grain ZnO on the outer surface, and finally lost as Zn vapor.
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Affiliation(s)
- Rui Geng
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, Shanxi, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yacong Liu
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, Shanxi, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jie Gao
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, Shanxi, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yanxia Guo
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, Shanxi, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mei Dong
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, Shanxi, China
| | - Sen Wang
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, Shanxi, China
| | - Weibin Fan
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, Shanxi, China
| | - Jianguo Wang
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, Shanxi, China
| | - Zhangfeng Qin
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, Shanxi, China
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4
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Heydarpoor S, Abbasi F, Jalili K, Najafpour M. Synthesis of core-shell PS/PMMA expandable particles via seeded suspension polymerization. JOURNAL OF POLYMER RESEARCH 2015. [DOI: 10.1007/s10965-015-0789-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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5
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XAFS Applications on Polymers and Related Materials. ACTA POLYM SIN 2014. [DOI: 10.3724/sp.j.1105.2014.13303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Nho HW, Kim JY, Wang J, Shin HJ, Choi SY, Yoon TH. Scanning transmission X-ray microscopy probe for in situ mechanism study of graphene-oxide-based resistive random access memory. JOURNAL OF SYNCHROTRON RADIATION 2014; 21:170-176. [PMID: 24365933 DOI: 10.1107/s1600577513026696] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 09/27/2013] [Indexed: 06/03/2023]
Abstract
Here, an in situ probe for scanning transmission X-ray microscopy (STXM) has been developed and applied to the study of the bipolar resistive switching (BRS) mechanism in an Al/graphene oxide (GO)/Al resistive random access memory (RRAM) device. To perform in situ STXM studies at the C K- and O K-edges, both the RRAM junctions and the I0 junction were fabricated on a single Si3N4 membrane to obtain local XANES spectra at these absorption edges with more delicate I0 normalization. Using this probe combined with the synchrotron-based STXM technique, it was possible to observe unique chemical changes involved in the BRS process of the Al/GO/Al RRAM device. Reversible oxidation and reduction of GO induced by the externally applied bias voltages were observed at the O K-edge XANES feature located at 538.2 eV, which strongly supported the oxygen ion drift model that was recently proposed from ex situ transmission electron microscope studies.
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Affiliation(s)
- Hyun Woo Nho
- Department of Chemistry, Hanyang University, 222 Wangsimniro, Seoul 133-791, Republic of Korea
| | - Jong Yun Kim
- Department of Chemistry, Hanyang University, 222 Wangsimniro, Seoul 133-791, Republic of Korea
| | - Jian Wang
- Canadian Light Source Inc., University of Saskatchewan, 44 Innovation Boulevard, Saskatoon, Saskatchewan, Canada S7N 2V3
| | - Hyun-Joon Shin
- Pohang Accelerator Laboratory and Department of Physics, Pohang University of Science and Technology, 80 Jigokro-127-beongil, Pohang, Gyeongbuk 790-834, Republic of Korea
| | - Sung-Yool Choi
- Department of Electrical Engineering and Graphene Research Center, KAIST, 291 Daehak-ro, Daejeon 305-701, Republic of Korea
| | - Tae Hyun Yoon
- Department of Chemistry, Hanyang University, 222 Wangsimniro, Seoul 133-791, Republic of Korea
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Mu Y, Qiu T, Li X, Guan Y, Zhang S, Li X. Layer-by-layer synthesis of multilayer core-shell latex and the film formation properties. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:4968-4978. [PMID: 21425825 DOI: 10.1021/la104862h] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Polymer latex particles were synthesized with multilayer core-shell structure via surface cross-linking emulsion polymerization. The latex core is coated with a five-layer shell. The polymerization was done in a semicontinuous fashion monitored by a dynamic laser scattering (DLS). The copolymer in each layer is designed with alternating high and low glass transition temperature (T(g)). Divinylbenzene (DVB) was added as the cross-linking agent in the synthesis of the "hard" layers to prevent the molecular diffusion from the adjacent "soft" layers. The layer-by-layer increment on the latex core is proved by the alternating changes on the film-formation capabilities of different latex emulsions at room temperature in correspondence with the variance in the T(g) of the outermost polymer layer. The detailed morphologies of the films formed by the latex with different number of layers were characterized by atom force microscopy (AFM). The deformation of the latex particles is largely depended on the nature of the polymer in the outermost layer of the latex particles. Further characterization carried out by multifrequency temperature-modulated differential scanning calorimetry (TOPEM-DSC) confirmed the layer-by-layer structure of the particles, although the molecular redistribution and the interlayer structures were observed. The work provides a routine toward the synthesis of multilayer polymer latexes.
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Affiliation(s)
- Yuanchun Mu
- College of Materials Science and Engineering, Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Key Laboratory for Nanomaterials, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029, PR China
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Yang M, Wang G, Ma H. An efficient approach for production of polystyrene/poly(4-vinylpridine) particles with various morphologies based on dynamic control. Chem Commun (Camb) 2011; 47:911-3. [DOI: 10.1039/c0cc03435e] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Li J, Hitchcock AP, Stöver HDH. Pickering emulsion templated interfacial atom transfer radical polymerization for microencapsulation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:17926-17935. [PMID: 21028818 DOI: 10.1021/la102867v] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This Article describes a new microencapsulation method based on a Pickering emulsion templated interfacial atom transfer radical polymerization (PETI-ATRP). Cationic LUDOX CL nanoparticles were coated electrostatically with an anionic polymeric ATRP initiator, poly(sodium styrene sulfonate-co-2-(2-bromoisobutyryloxy)ethyl methacrylate) (PSB), prepared by radical copolymerization of sodium styrene sulfonate and 2-(2-bromoisobutyryloxy)ethyl methacrylate (BIEM). The resulting PSB-modified CL particles were surface active and could be used to stabilize oil-in-water Pickering emulsions. ATRP of water-soluble cross-linking monomers, confined to the oil-water interface by the surface-bound PSB, then led to nanoparticle/polymer composite shells. This method allowed encapsulation of core solvents (xylene, hexadecane, perfluoroheptane) with different solubility parameters. The microcapsule (MC) wall chemistry could accommodate different monomers, demonstrating the versatility of this method. Double-walled MCs were formed by sequentially carrying out PETI-ATRP and in situ polymerization of encapsulated monomers. The double-walled structure was verified by both transmission electron microscopy (TEM) and scanning transmission X-ray microscopy (STXM).
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Affiliation(s)
- Jian Li
- Department of Chemistry & Chemical Biology, McMaster University, Hamilton, ON, Canada L8S 4M1
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Tanaka T, Saito N, Okubo M. Control of Layer Thickness of Onionlike Multilayered Composite Polymer Particles Prepared by the Solvent Evaporation Method. Macromolecules 2009. [DOI: 10.1021/ma901100n] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Takuya Tanaka
- Graduate School of Engineering, Kobe University, Kobe 657-8501, Japan
| | - Naohiko Saito
- Graduate School of Engineering, Kobe University, Kobe 657-8501, Japan
| | - Masayoshi Okubo
- Graduate School of Engineering, Kobe University, Kobe 657-8501, Japan
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11
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Zetterlund PB, Aldabbagh F, Okubo M. Controlled/living heterogeneous radical polymerization in supercritical carbon dioxide. ACTA ACUST UNITED AC 2009. [DOI: 10.1002/pola.23432] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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12
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Zhu Y, Yu H, Zhu J, Zhao G, Jiang W, Yang X. Morphological transition of dry vesicles into onion-like multilamellar micelles induced through heating at high temperature. Chem Phys Lett 2008. [DOI: 10.1016/j.cplett.2008.06.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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13
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NEXAFS microscopy and resonant scattering: Composition and orientation probed in real and reciprocal space. POLYMER 2008. [DOI: 10.1016/j.polymer.2007.10.030] [Citation(s) in RCA: 239] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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14
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Felten A, Bittencourt C, Pireaux JJ, Reichelt M, Mayer J, Hernandez-Cruz D, Hitchcock AP. Individual multiwall carbon nanotubes spectroscopy by scanning transmission X-ray microscopy. NANO LETTERS 2007; 7:2435-40. [PMID: 17625906 DOI: 10.1021/nl071134e] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Scanning transmission X-ray microscopy (STXM) has been used to probe the electronic structure of individual multiwall carbon nanotubes by chemical mapping at the nanoscale. Carbon 1s near-edge X-ray absorption fine structure (NEXAFS) spectra of individual structures are shown to be able to differentiate carbon nanotubes from onionlike carbon nanoparticles and to differentiate nanotubes synthesized by different growth methods. Imaging of the very same region by both STXM and transmission electron microscopy is shown to be a very useful and complementary approach.
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Affiliation(s)
- Alexandre Felten
- LISE, University of Namur, 61 rue de Bruxelles, 5000 Namur, Belgium.
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Kim JW, Larsen RJ, Weitz DA. Synthesis of Nonspherical Colloidal Particles with Anisotropic Properties. J Am Chem Soc 2006; 128:14374-7. [PMID: 17076511 DOI: 10.1021/ja065032m] [Citation(s) in RCA: 322] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We describe a promising and flexible technique for fabricating uniform nonspherical particles with anisotropic phase and surface properties. Our approach is based on the seeded polymerization technique in which monomer-swollen particles are polymerized. The polymerization causes a phase separation to occur, giving rise to two-phase nonspherical particles. We show that the elastic contraction of the swollen polymer particles induced by elevated polymerization temperatures plays an important role in the phase separation. Moreover, chemical anisotropy of nonspherical particles can be obtained by using immiscible polymer pairs and by employing surface treatments. Furthermore, we are able to produce amphiphilic dumbbell particles consisting of two different bulbs: hydrophilic poly (ethylene imine)-coated polystyrene and hydrophobic polystyrene. Controlled geometries of these amphiphilic nonspherical particles will allow a wide range of potential applications, such as engineered colloid surfactants.
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Affiliation(s)
- Jin-Woong Kim
- Division of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
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Wei Z, Gourevich I, Field L, Coombs N, Kumacheva E. TEM Imaging of Polymer Multilayer Particles: Advantages, Limitations, and Artifacts. Macromolecules 2006. [DOI: 10.1021/ma052029z] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Zhixiang Wei
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada; Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada; and Institute of Biomaterials & Biomedical Engineering, University of Toronto, 4 Taddle Creek Road, Toronto, Ontario M5S 3G9, Canada
| | - Ilya Gourevich
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada; Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada; and Institute of Biomaterials & Biomedical Engineering, University of Toronto, 4 Taddle Creek Road, Toronto, Ontario M5S 3G9, Canada
| | - Lora Field
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada; Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada; and Institute of Biomaterials & Biomedical Engineering, University of Toronto, 4 Taddle Creek Road, Toronto, Ontario M5S 3G9, Canada
| | - Neil Coombs
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada; Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada; and Institute of Biomaterials & Biomedical Engineering, University of Toronto, 4 Taddle Creek Road, Toronto, Ontario M5S 3G9, Canada
| | - Eugenia Kumacheva
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada; Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada; and Institute of Biomaterials & Biomedical Engineering, University of Toronto, 4 Taddle Creek Road, Toronto, Ontario M5S 3G9, Canada
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Hitchcock AP, Stöver HDH, Croll LM, Childs RF. Chemical Mapping of Polymer Microstructure Using Soft X-ray Spectromicroscopy. Aust J Chem 2005. [DOI: 10.1071/ch05054] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Recently, synchrotron-based soft X-ray spectromicroscopy techniques have been applied to studies of polymer microstructure at the ~50 nm spatial scale. Functional group based chemical speciation and quantitative mapping is provided by near edge X-ray absorption fine structure spectral (NEXAFS) contrast. The techniques, sample data, and analysis methods of scanning transmission X-ray microscopy (STXM) and X-ray photoemission electron microscopy (X-PEEM) are outlined. The capabilities of STXM are illustrated by results from recent studies of (a) controlled release microcapsules and microspheres, (b) microcapsules being developed for gene therapy applications, (c) conducting polymer films studied in the presence of electrolyte and under potential control, and (d) studies of protein interactions with patterned polymer surfaces. In the latter area, the capabilities of STXM and X-PEEM are compared directly.
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