1
|
Miyata T, Sato YK, Kawagoe Y, Shirasu K, Wang HF, Kumagai A, Kinoshita S, Mizukami M, Yoshida K, Huang HH, Okabe T, Hagita K, Mizoguchi T, Jinnai H. Effect of inorganic material surface chemistry on structures and fracture behaviours of epoxy resin. Nat Commun 2024; 15:1898. [PMID: 38459006 PMCID: PMC10923874 DOI: 10.1038/s41467-024-46138-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Accepted: 02/15/2024] [Indexed: 03/10/2024] Open
Abstract
The mechanisms underlying the influence of the surface chemistry of inorganic materials on polymer structures and fracture behaviours near adhesive interfaces are not fully understood. This study demonstrates the first clear and direct evidence that molecular surface segregation and cross-linking of epoxy resin are driven by intermolecular forces at the inorganic surfaces alone, which can be linked directly to adhesive failure mechanisms. We prepare adhesive interfaces between epoxy resin and silicon substrates with varying surface chemistries (OH and H terminations) with a smoothness below 1 nm, which have different adhesive strengths by ~13 %. The epoxy resins within sub-nanometre distance from the surfaces with different chemistries exhibit distinct amine-to-epoxy ratios, cross-linked network structures, and adhesion energies. The OH- and H-terminated interfaces exhibit cohesive failure and interfacial delamination, respectively. The substrate surface chemistry impacts the cross-linked structures of the epoxy resins within several nanometres of the interfaces and the adsorption structures of molecules at the interfaces, which result in different fracture behaviours and adhesive strengths.
Collapse
Affiliation(s)
- Tomohiro Miyata
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi, 980-8577, Japan
| | - Yohei K Sato
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi, 980-8577, Japan
| | - Yoshiaki Kawagoe
- Department of Aerospace Engineering, Graduate School of Engineering, Tohoku University, 6-6-01 Aramaki Aza Aoba, Aoba-ku, Sendai, Miyagi, 980-8579, Japan.
| | - Keiichi Shirasu
- Department of Finemechanics, Graduate School of Engineering, Tohoku University, 6-6-01 Aramaki Aza Aoba, Aoba-ku, Sendai, Miyagi, 980-8579, Japan.
| | - Hsiao-Fang Wang
- Department of Chemical and Materials Engineering, National Central University, No. 300, Zhongda Rd., Zhongli Dist., Taoyuan City, 320317, Taiwan
| | - Akemi Kumagai
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi, 980-8577, Japan
| | - Sora Kinoshita
- Department of Applied Chemistry, Graduate School of Engineering, Tohoku University, 6-6-07 Aramaki Aza Aoba, Aoba-ku, Sendai, Miyagi, 980-8579, Japan
| | - Masashi Mizukami
- New Industry Creation Hatchery Center, Tohoku University, Sendai, Miyagi, 980-0845, Japan
| | - Kaname Yoshida
- Nanostructures Research Laboratory, Japan Fine Ceramics Center, Nagoya, Aichi, 456-8587, Japan
| | - Hsin-Hui Huang
- Nanostructures Research Laboratory, Japan Fine Ceramics Center, Nagoya, Aichi, 456-8587, Japan
| | - Tomonaga Okabe
- Department of Aerospace Engineering, Graduate School of Engineering, Tohoku University, 6-6-01 Aramaki Aza Aoba, Aoba-ku, Sendai, Miyagi, 980-8579, Japan
- Research Center for Structural Materials, Polymer Matrix Hybrid Composite Materials Group, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047, Japan
- Department of Materials Science and Engineering, University of Washington, BOX 352120, Seattle, WA, 98195, USA
| | - Katsumi Hagita
- Department of Applied Physics, National Defense Academy, Yokosuka, Kanagawa, 239-0811, Japan
| | - Teruyasu Mizoguchi
- Institute of Industrial Science, The University of Tokyo, Meguro-ku, Tokyo, 153-8505, Japan
| | - Hiroshi Jinnai
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi, 980-8577, Japan.
| |
Collapse
|
2
|
Reimers JR, Yang J, Darwish N, Kosov DS. Silicon - single molecule - silicon circuits. Chem Sci 2021; 12:15870-15881. [PMID: 35024111 PMCID: PMC8672724 DOI: 10.1039/d1sc04943g] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 10/28/2021] [Indexed: 12/23/2022] Open
Abstract
In 2020, silicon - molecule - silicon junctions were fabricated and shown to be on average one third as conductive as traditional junctions made using gold electrodes, but in some instances to be even more conductive, and significantly 3 times more extendable and 5 times more mechanically stable. Herein, calculations are performed of single-molecule junction structure and conductivity pertaining to blinking and scanning-tunnelling-microscopy (STM) break junction (STMBJ) experiments performed using chemisorbed 1,6-hexanedithiol linkers. Some strikingly different characteristics are found compared to analogous junctions formed using the metals which, to date, have dominated the field of molecular electronics. In the STMBJ experiment, following retraction of the STM tip after collision with the substrate, unterminated silicon surface dangling bonds are predicted to remain after reaction of the fresh tips with the dithiol solute. These dangling bonds occupy the silicon band gap and are predicted to facilitate extraordinary single-molecule conductivity. Enhanced junction extendibility is attributed to junction flexibility and the translation of adsorbed molecules between silicon dangling bonds. The calculations investigate a range of junction atomic-structural models using density-functional-theory (DFT) calculations of structure, often explored at 300 K using molecular dynamics (MD) simulations. These are aided by DFT calculations of barriers for passivation reactions of the dangling bonds. Thermally averaged conductivities are then evaluated using non-equilibrium Green's function (NEGF) methods. Countless applications through electronics, nanotechnology, photonics, and sensing are envisaged for this technology.
Collapse
Affiliation(s)
- Jeffrey R Reimers
- International Centre for Quantum and Molecular Structures and School of Physics, Shanghai University Shanghai 200444 China
- School of Mathematical and Physical Sciences, University of Technology Sydney NSW 2007 Australia
| | - Junhao Yang
- International Centre for Quantum and Molecular Structures and School of Physics, Shanghai University Shanghai 200444 China
| | - Nadim Darwish
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University Bentley WA 6102 Australia
| | - Daniel S Kosov
- College of Science and Engineering, James Cook University Townsville QLD 4811 Australia
| |
Collapse
|
3
|
Soliman AIA, Wu CT, Utsunomiya T, Ichii T, Sugimura H. Controlled Growth of Organosilane Micropatterns on Hydrophilic and Hydrophobic Surfaces Templated by Vacuum Ultraviolet Photolithography. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:13932-13940. [PMID: 34780193 DOI: 10.1021/acs.langmuir.1c02516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In this report, micropatterns of (3-aminopropyl)trimethoxysilane (APTMS) were developed on hydrophilic and hydrophobic surfaces after patterning using 172 nm vacuum ultraviolet (VUV) photolithography. Self-assembled monolayers (SAMs) formed on Si substrates through UV hydrosilylation of 1-hexadecene (HD) and 10-undecenoic acid (UDA) were used as hydrophilic and hydrophobic surfaces, respectively. For templating the HD- and UDA-SAMs, the VUV light was exposed to HD- and UDA-SAMs from the slits of photomasks in atmospheric and evacuated environments, respectively. Various oxygenated groups were generated at the exposed domains of HD-SAM, while the COOH groups were trimmed from the irradiated domains of UDA-SAM. The APTMS molecules were immobilized on the domains that were terminated by oxygenated groups after chemical vapor deposition (CVD). The thicknesses of the developed APTMS micropatterns increased significantly by raising the CVD temperature and in the presence of ambient air in the CVD Teflon container as well. The increase in thicknesses was ascribed to the formation of APTMS multilayers, which were mediated by H3N+ ions. Also, the developed APTMS micropatterns on the UDA-SAM patterned by VUV light irradiation in a high-vacuum environment (HV-VUV) were thicker than those on the VUV/(O) patterned HD-SAM due to the presence of inactive oxygenated groups at the surface of VUV/(O)-terminated domains of HD-SAM such as COO-C and C-O-C groups. The presence of water or ambient air facilitated the silane coupling between the silyl groups with the oxygenated and amino groups The combination of VUV photolithography and the CVD method with control of the conditions would enable us to control the thicknesses and shapes of the developed APTMS micropatterns. These findings illustrate the applicability of VUV photolithography for templating hydrophobic and hydrophobic surfaces toward the development of organosilane architectures, which can be feasible for several applications.
Collapse
Affiliation(s)
- Ahmed I A Soliman
- Department of Materials Science and Engineering, Kyoto University, Yoshida-hommachi, Sakyo-Ku, Kyoto 606-8501, Japan
- Chemistry Department, Faculty of Science, Assiut University, Assiut 71516, Egypt
| | - Cheng-Tse Wu
- Department of Materials Science and Engineering, Kyoto University, Yoshida-hommachi, Sakyo-Ku, Kyoto 606-8501, Japan
| | - Toru Utsunomiya
- Department of Materials Science and Engineering, Kyoto University, Yoshida-hommachi, Sakyo-Ku, Kyoto 606-8501, Japan
| | - Takashi Ichii
- Department of Materials Science and Engineering, Kyoto University, Yoshida-hommachi, Sakyo-Ku, Kyoto 606-8501, Japan
| | - Hiroyuki Sugimura
- Department of Materials Science and Engineering, Kyoto University, Yoshida-hommachi, Sakyo-Ku, Kyoto 606-8501, Japan
| |
Collapse
|
4
|
Rahpeima S, Dief EM, Ciampi S, Raston CL, Darwish N. Impermeable Graphene Oxide Protects Silicon from Oxidation. ACS APPLIED MATERIALS & INTERFACES 2021; 13:38799-38807. [PMID: 34342425 DOI: 10.1021/acsami.1c06495] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The presence of a natural silicon oxide (SiOx) layer over the surface of silicon (Si) has been a roadblock for hybrid semiconductor and organic electronics technology. The presence of an insulating oxide layer is a limiting operational factor, which blocks charge transfer and therefore electrical signals for a range of applications. Etching the SiOx layer by fluoride solutions leaves a reactive Si-H surface that is only stable for few hours before it starts reoxidizing under ambient conditions. Controlled passivation of silicon is also of key importance for improving Si photovoltaic efficiency. Here, we show that a thin layer of graphene oxide (GOx) prevents Si surfaces from oxidation under ambient conditions for more than 30 days. In addition, we show that the protective GOx layer can be modified with molecules enabling a functional surface that allows for further chemical conjugation or connections with upper electrodes, while preserving the underneath Si in a nonoxidized form. The GOx layer can be switched electrochemically to reduced graphene oxide, allowing the development of a dynamic material for molecular electronics technologies. These findings demonstrate that 2D materials are alternatives to organic self-assembled monolayers that are typically used to protect and tune the properties of Si and open a realm of possibilities that combine Si and 2D materials technologies.
Collapse
Affiliation(s)
- Soraya Rahpeima
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University, Bentley, Perth, Western Australia 6102, Australia
- Flinders Institute for Nanoscale Science and Technology, College of Science and Engineering, Flinders University, Bedford Park, South Australia 5042, Australia
| | - Essam M Dief
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University, Bentley, Perth, Western Australia 6102, Australia
| | - Simone Ciampi
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University, Bentley, Perth, Western Australia 6102, Australia
| | - Colin L Raston
- Flinders Institute for Nanoscale Science and Technology, College of Science and Engineering, Flinders University, Bedford Park, South Australia 5042, Australia
| | - Nadim Darwish
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University, Bentley, Perth, Western Australia 6102, Australia
| |
Collapse
|
5
|
Kubota W, Utsunomiya T, Ichii T, Sugimura H. Chemical Etching of Silicon Assisted by Graphene Oxide in an HF-HNO 3 Solution and Its Catalytic Mechanism. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:9920-9926. [PMID: 34351164 DOI: 10.1021/acs.langmuir.1c01681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Chemical etching of silicon assisted by various types of carbon materials is drawing much attention for the fabrication of silicon micro/nanostructures. We developed a method of chemical etching of silicon that utilizes graphene oxide (GO) sheets to promote the etching reaction in a hydrofluoric acid-nitric acid (HF-HNO3) etchant. By using an optimized composition of the HF-HNO3 etchant, the etching rate under the GO sheets was 100 times faster than that of our HF-H2O2 system used in a previous report. Kinetic analyses showed that the activation energy of the etching reaction was almost the same at both the bare silicon and GO-covered areas. We propose that adsorption sites for the reactant in the GO sheets enhance the reaction frequency, leading to a deeper etching in the GO areas than the bare areas. Furthermore, GO sheets with more defects were found to have higher catalytic activities. This suggests that defects in the GO sheets function as adsorption sites for the reactant, thereby enhancing the etching rate under the sheets.
Collapse
Affiliation(s)
- Wataru Kubota
- Department of Materials Science and Engineering, Graduate School of Engineering, Kyoto University, Kyoto 606-8501, Japan
| | - Toru Utsunomiya
- Department of Materials Science and Engineering, Graduate School of Engineering, Kyoto University, Kyoto 606-8501, Japan
| | - Takashi Ichii
- Department of Materials Science and Engineering, Graduate School of Engineering, Kyoto University, Kyoto 606-8501, Japan
| | - Hiroyuki Sugimura
- Department of Materials Science and Engineering, Graduate School of Engineering, Kyoto University, Kyoto 606-8501, Japan
| |
Collapse
|
6
|
Peiris CR, Ciampi S, Dief EM, Zhang J, Canfield PJ, Le Brun AP, Kosov DS, Reimers JR, Darwish N. Spontaneous S-Si bonding of alkanethiols to Si(111)-H: towards Si-molecule-Si circuits. Chem Sci 2020; 11:5246-5256. [PMID: 34122981 PMCID: PMC8159313 DOI: 10.1039/d0sc01073a] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We report the synthesis of covalently linked self-assembled monolayers (SAMs) on silicon surfaces, using mild conditions, in a way that is compatible with silicon-electronics fabrication technologies. In molecular electronics, SAMs of functional molecules tethered to gold via sulfur linkages dominate, but these devices are not robust in design and not amenable to scalable manufacture. Whereas covalent bonding to silicon has long been recognized as an attractive alternative, only formation processes involving high temperature and/or pressure, strong chemicals, or irradiation are known. To make molecular devices on silicon under mild conditions with properties reminiscent of Au–S ones, we exploit the susceptibility of thiols to oxidation by dissolved O2, initiating free-radical polymerization mechanisms without causing oxidative damage to the surface. Without thiols present, dissolved O2 would normally oxidize the silicon and hence reaction conditions such as these have been strenuously avoided in the past. The surface coverage on Si(111)–H is measured to be very high, 75% of a full monolayer, with density-functional theory calculations used to profile spontaneous reaction mechanisms. The impact of the Si–S chemistry in single-molecule electronics is demonstrated using STM-junction approaches by forming Si–hexanedithiol–Si junctions. Si–S contacts result in single-molecule wires that are mechanically stable, with an average lifetime at room temperature of 2.7 s, which is five folds higher than that reported for conventional molecular junctions formed between gold electrodes. The enhanced “ON” lifetime of this single-molecule circuit enables previously inaccessible electrical measurements on single molecules. Spontaneously formed Si–S bonds enable monolayer and single-molecule Si–molecule–Si circuits.![]()
Collapse
Affiliation(s)
- Chandramalika R Peiris
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University Bentley WA 6102 Australia
| | - Simone Ciampi
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University Bentley WA 6102 Australia
| | - Essam M Dief
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University Bentley WA 6102 Australia
| | - Jinyang Zhang
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University Bentley WA 6102 Australia
| | - Peter J Canfield
- International Centre for Quantum and Molecular Structures, School of Physics, Shanghai University Shanghai 200444 China.,School of Chemistry, The University of Sydney NSW 2006 Australia
| | - Anton P Le Brun
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organization (ANSTO) Lucas Heights NSW 2234 Australia
| | - Daniel S Kosov
- College of Science and Engineering, James Cook University Townsville QLD 4811 Australia
| | - Jeffrey R Reimers
- International Centre for Quantum and Molecular Structures, School of Physics, Shanghai University Shanghai 200444 China.,School of Mathematical and Physical Sciences, University of Technology Sydney NSW 2007 Australia
| | - Nadim Darwish
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University Bentley WA 6102 Australia
| |
Collapse
|
7
|
Wu CT, Soliman AIA, Utsunomiya T, Ichii T, Sugimura H. Formation of submicron-sized silica patterns on flexible polymer substrates based on vacuum ultraviolet photo-oxidation. RSC Adv 2019; 9:32313-32322. [PMID: 35530761 PMCID: PMC9072887 DOI: 10.1039/c9ra07256j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 09/30/2019] [Indexed: 11/21/2022] Open
Abstract
Formation of precise and high-resolution silica micropatterns on polymer substrates is of importance in surface structuring for flexible device fabrication of optics, microelectronic, and biotechnology. To achieve that, substrates modified with affinity-patterns serve as a strategy for site-selective deposition. In the present paper, vacuum ultraviolet (VUV) treatment is utilized to achieve spatially-controlled surface functionalization on a cyclo-olefin polymer (COP) substrate. An organosilane, 2,4,6,8-tetramethylcyclotetrasiloxane (TMCTS), preferentially deposits on the functionalized regions. Well-defined patterns of TMCTS are formed with a minimum feature of ∼500 nm. The secondary VUV/(O)-treatment converts TMCTS into SiO x , meanwhile etches the bare COP surface, forming patterned SiO x /COP microstructures with an average height of ∼150 nm. The resulting SiO x patterns retain a good copy of TMCTS patterns, which are also consistent with the patterns of photomask used in polymer affinity-patterning. The high quality SiO x patterns are of interests in microdevice fabrication, and the hydrophilicity contrast and adjustable heights reveal their potential application as a "stamp" for microcontact printing (μCP) techniques.
Collapse
Affiliation(s)
- Cheng-Tse Wu
- Department of Materials Science and Engineering, Graduate School of Engineering, Kyoto University Kyoto 606-8501 Japan +81-75-753-9131
| | - Ahmed I A Soliman
- Department of Materials Science and Engineering, Graduate School of Engineering, Kyoto University Kyoto 606-8501 Japan +81-75-753-9131.,Chemistry Department, Faculty of Science, Assiut University Assiut 71516 Egypt
| | - Toru Utsunomiya
- Department of Materials Science and Engineering, Graduate School of Engineering, Kyoto University Kyoto 606-8501 Japan +81-75-753-9131
| | - Takashi Ichii
- Department of Materials Science and Engineering, Graduate School of Engineering, Kyoto University Kyoto 606-8501 Japan +81-75-753-9131
| | - Hiroyuki Sugimura
- Department of Materials Science and Engineering, Graduate School of Engineering, Kyoto University Kyoto 606-8501 Japan +81-75-753-9131
| |
Collapse
|