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Koch T, Zhang W, Tran TT, Wang Y, Mikitisin A, Puchhammer J, Greer JR, Ovsianikov A, Chalupa-Gantner F, Lunzer M. Approaching Standardization: Mechanical Material Testing of Macroscopic Two-Photon Polymerized Specimens. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2308497. [PMID: 38303404 DOI: 10.1002/adma.202308497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 01/02/2024] [Indexed: 02/03/2024]
Abstract
Two-photon polymerization (2PP) is becoming increasingly established as additive manufacturing technology for microfabrication due to its high-resolution and the feasibility of generating complex parts. Until now, the high resolution of 2PP is also its bottleneck, as it limited throughput and therefore restricted the application to the production of microparts. Thus, mechanical properties of 2PP materials can only be characterized using nonstandardized specialized microtesting methods. Due to recent advances in 2PP technology, it is now possible to produce parts in the size of several millimeters to even centimeters, finally permitting the fabrication of macrosized testing specimens. Besides suitable hardware systems, 2PP materials exhibiting favorable mechanical properties that allow printing of up-scaled parts are strongly demanded. In this work, the up-scalability of three different photopolymers is investigated using a high-throughput 2PP system and low numerical aperture optics. Testing specimens in the cm-range are produced and tested with common or even standardized material testing methods available in conventionally equipped polymer testing labs. Examples of the characterization of mechanical, thermo-mechanical, and fracture properties of 2PP processed materials are shown. Additionally, aspects such as postprocessing and aging are investigated. This lays a foundation for future expansion of the 2PP technology to broader industrial application.
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Affiliation(s)
- Thomas Koch
- Institute of Materials Science and Technology, TU Wien, Vienna, 1060, Austria
| | - Wenxin Zhang
- Division of Engineering and Applied Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Thomas T Tran
- Division of Engineering and Applied Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Yingjin Wang
- Division of Engineering and Applied Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Adrian Mikitisin
- Central Facility for Electron Microscopy, RWTH Aachen, 52074, Aachen, Germany
| | - Jakob Puchhammer
- Institute of Materials Science and Technology, TU Wien, Vienna, 1060, Austria
| | - Julia R Greer
- Division of Engineering and Applied Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
- Kavli Nanoscience Institute, California Institute of Technology, Pasadena, CA, 91125, USA
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Tang J, Xu N, Ren A, Ma L, Xu W, Han Z, Chen Z, Li Q. Two-Orders-of-Magnitude Enhancement of Photoinitiation Activity via a Simple Surface Engineering of Metal Nanoclusters. Angew Chem Int Ed Engl 2024; 63:e202403645. [PMID: 38530138 DOI: 10.1002/anie.202403645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 03/21/2024] [Accepted: 03/25/2024] [Indexed: 03/27/2024]
Abstract
Development of high-performance photoinitiator is the key to enhance the printing speed, structure resolution and product quality in 3D laser printing. Here, to improve the printing efficiency of 3D laser nanoprinting, we investigate the underlying photochemistry of gold and silver nanocluster initiators under multiphoton laser excitation. Experimental results and DFT calculations reveal the high cleavage probability of the surface S-C bonds in gold and silver nanoclusters which generate multiple radicals. Based on this understanding, we design several alkyl-thiolated gold nanoclusters and achieve a more than two-orders-of-magnitude enhancement of photoinitiation activity, as well as a significant improvement in printing resolution and fabrication window. Overall, this work for the first time unveils the detailed radical formation pathways of gold and silver nanoclusters under multiphoton activation and substantially improves their photoinitiation sensitivity via surface engineering, which pushes the limit of the printing efficiency of 3D laser lithography.
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Affiliation(s)
- Jin Tang
- Ministry of Education Key Laboratory of Macromolecular Synthesis and Functionalization; Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Ning Xu
- School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310058, China
- Department of Physics, School of Physical Science and Technology, Ningbo University, Ningbo, 315211, China
| | - An Ren
- The State Key Laboratory of Fluid Power and Mechatronic Systems. School of Mechanical Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Liang Ma
- The State Key Laboratory of Fluid Power and Mechatronic Systems. School of Mechanical Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Wenwu Xu
- Department of Physics, School of Physical Science and Technology, Ningbo University, Ningbo, 315211, China
| | - Zhongkang Han
- School of Materials Science and Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Zijie Chen
- Ministry of Education Key Laboratory of Macromolecular Synthesis and Functionalization; Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Qi Li
- Ministry of Education Key Laboratory of Macromolecular Synthesis and Functionalization; Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, China
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Masilamani G, Krishna GR, Debnath S, Bedi A. Origin of Optoelectronic Contradictions in 3,4-Cycloalkyl[ c]-chalcogenophenes: A Computational Study. Polymers (Basel) 2023; 15:4240. [PMID: 37959920 PMCID: PMC10650045 DOI: 10.3390/polym15214240] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 10/21/2023] [Accepted: 10/24/2023] [Indexed: 11/15/2023] Open
Abstract
The planar morphology of the backbone significantly contributes to the subtle optoelectronic features of π-conjugated polymers. On the other hand, the atomistic tuning of an otherwise identical π-backbone could also impact optoelectronic properties systematically. In this manuscript, we compare a series of 3,4-cycloalkylchalcogenophenes by tuning them atomistically using group-16 elements. Additionally, the effect of systematically extending these building blocks in the form of oligomers and polymers is studied. The size of the 3,4-substitution affected the morphology of the oligomers. In addition, the heteroatoms contributed to a further alteration in their geometry and resultant optoelectronic properties. The chalcogenophenes, containing smaller 3,4-cycloalkanes, resulted in lower bandgap oligomers or polymers compared to those with larger 3,4-cycloalkanes. Natural bonding orbital (NBO) calculations were performed to understand the disparity alongside the contour maps of frontier molecular orbitals (FMO).
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Affiliation(s)
- Ganesh Masilamani
- Department of Chemistry, SRM Institute of Science and Technology, Kattankulathur 603203, India
| | - Gamidi Rama Krishna
- Organic Chemistry Division, CSIR—National Chemical Laboratory, Pune 411008, India
| | - Sashi Debnath
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Anjan Bedi
- Department of Chemistry, SRM Institute of Science and Technology, Kattankulathur 603203, India
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Verma P, Tasior M, Roy P, Meech SR, Gryko DT, Vauthey E. Excited-state symmetry breaking in quadrupolar pull-push-pull molecules: dicyanovinyl vs. cyanophenyl acceptors. Phys Chem Chem Phys 2023; 25:22689-22699. [PMID: 37602791 PMCID: PMC10467566 DOI: 10.1039/d3cp02810k] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 08/02/2023] [Indexed: 08/22/2023]
Abstract
A significant number of quadrupolar dyes behave as their dipolar analogues when photoexcited in polar environments. This is due to the occurrence of excited-state symmetry breaking (ES-SB), upon which the electronic excitation, initially distributed over the whole molecule, localises preferentially on one side. Here, we investigate the ES-SB properties of two A-D-A dyes, consisting of a pyrrolo-pyrrole donor (D) and either cyanophenyl or dicyanovinyl acceptors (A). For this, we use time-resolved vibrational spectroscopy, comparing IR absorption and femtosecond stimulated Raman spectroscopies. Although dicyanovinyl is a stronger electron-withdrawing group, ES-SB is not observed with the dicyanovinyl-based dye even in highly polar media, whereas it already takes place in weakly polar solvents with dyes containing cyanophenyl accepting groups. This difference is attributed to the large electronic coupling between the D-A branches in the former dye, whose loss upon symmetry breaking cannot be counterbalanced by a gain in solvation energy. Comparison with analogues of the cyanophenyl-based dye containing different spacers reveals that interbranch coupling does not so much depend on the distance between the D-A subunits than on the nature of the spacer. We show that transient Raman spectra probe different modes of these centrosymmetric molecules but are consistent with the transient IR data. However, lifetime broadening of the Raman bands, probably due to the resonance enhancement, may limit the application of this technique for monitoring ES-SB.
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Affiliation(s)
- Pragya Verma
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, CH-1211, Geneva 4, Switzerland.
| | - Mariusz Tasior
- Institute of Organic Chemistry, Polish Academy of Sciences, 01-224 Warsaw, Poland
| | - Palas Roy
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Stephen R Meech
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Daniel T Gryko
- Institute of Organic Chemistry, Polish Academy of Sciences, 01-224 Warsaw, Poland
| | - Eric Vauthey
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, CH-1211, Geneva 4, Switzerland.
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