3D-printed slit nozzles for Fourier transform microwave spectroscopy

Dewberry, Christopher T.; Mackenzie, Rebecca B.; Green, Sue; Leopold, K. R.

doi:10.1063/1.4922852

Cited by 27 publications

(19 citation statements)

References 38 publications

(12 reference statements)

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“…Rotational spectra of the triflic acid hydrates were collected using a combined cavity and chirped-pulse Fourier transform microwave spectrometer, details of which have been given elsewhere. , Transition frequencies obtained on the chirped-pulse system were typically accurate to ∼12 kHz, while those obtained in the cavity mode of the spectrometer were accurate to ∼3 kHz. In the case of di-deuterated isotopologues, however, the dense deuterium hyperfine structure decreased the measurement accuracy such that only approximate line centers could be obtained.…”

Section: Experimental Methods and Resultsmentioning

confidence: 99%

Microwave Study of Triflic Acid Hydrates: Evidence for the Transition from Hydrogen-Bonded Clusters to a Microsolvated Ion Pair

2021

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Rotational spectra of the mono-, di-, and trihydrates of triflic acid, CF 3 SO 3 H•••(H 2 O) n=1−3 , have been recorded by pulsed nozzle Fourier transform microwave spectroscopy and spectroscopic constants obtained have been compared with values calculated at several levels of theory. The experimental results are consistent with the theoretical predictions presented here and elsewhere, indicating that with only one or two water molecules, triflic acid remains un-ionized in a cold molecular complex. The experiments further concur with theoretical predictions that the addition of a third water molecule transforms the system into what is best regarded as a hydrated hydronium triflate ion pair. Thus, only three water molecules are needed to induce ionization of triflic acid in a cold molecular cluster. This number is somewhat low compared with that for other simple protic acids and likely reflects the superacidity of triflic acid. Simple energetic arguments can be used to rationalize this result.

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Section: Experimental Methods and Resultsmentioning

confidence: 99%

Microwave Study of Triflic Acid Hydrates: Evidence for the Transition from Hydrogen-Bonded Clusters to a Microsolvated Ion Pair

2021

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“…The rotational spectrum of 3,5-difluoropyridine•••CO 2 was obtained using a Fourier transform microwave spectrometer with tandem cavity [9] and chirped-pulse [10] capabilities. Details of the instrument have been provided elsewhere [11,12]. Briefly, the cavity mode of the spectrometer operates along one axis and the chirped-pulse mode along an orthogonal axis.…”

Section: Experimental Methods and Resultsmentioning

confidence: 99%

“…Initially, a chirped pulse spectrum from 6-18 GHz was taken using our standard circular 0.8 mm orifice nozzle, but the number of observed transitions was insufficient to make definitive spectral assignments. Using a newly developed 3D-printed nozzle that terminates in a 1.25 x 0.0085 slit [12], however, a sufficient number of rotational transitions were observed that spectral assignments could be made and an initial rough fit generated. Figure 1 shows a comparison between the chirped-pulse spectra with the traditional nozzle and the slit nozzle.…”

Section: Experimental Methods and Resultsmentioning

confidence: 99%

Microwave spectrum and structure of the 3,5-difluoropyridine⋯CO2 van der Waals complex

Dewberry

Cornelius

Mackenzie

et al. 2016

Journal of Molecular Spectroscopy

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The rotational spectrum of the weakly bound complex 3,5-difluoropyridine•••CO 2 has been observed using pulsed-nozzle Fourier transform microwave spectroscopy. Spectroscopic constants are reported for the parent and 13 CO 2 isotopologues. The data indicate a planar structure in which the nitrogen approaches the carbon of the CO 2 with either a C 2v or effectively C 2v geometry in the ground vibrational state. The N•••C van der Waals bond distance is 2.8245(16) Å and the oxygen•••ortho-hydrogen distance is 3.091(2) Å. The N•••C van der Waals bond length is 0.027(8) Å longer than that previously determined for pyridineCO 2 , but is still considerably shorter than the 2.998 Å distance in HCN•••CO 2. M06-2X/6-311++G(3df,3pd) calculations place the binding energy of the complex at 4.3 kcal/mol (4.1 kcal/mol with counterpoise correction). The calculations further indicate that a secondary interaction between the ortho-hydrogens of the ring and the CO 2 oxygens account for ~50% of the total binding energy.

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“…While developments in accessible 3D printing and microcontrollers has seen widespread use amongst amateur users, these technologies have only seen limited application within the scientific community. Two examples of scientific equipment manufactured with 3D printing include static optical components[ 5 ] and supersonic expansion nozzles[ 6 ]. However, these are both simple products without moving parts.…”

Section: Introductionmentioning

confidence: 99%

“…The overall structure forms a paper several microns thick ( Fig 1a ) with lamellae that are highly interconnected in a honeycomb-like structure as pictured in Fig 1b . The GO papers used in this study are manufactured using a process called vacuum-assisted self-assembly[ 2 , 6 , 13 ] (VASA). The process involves the suspension of GO nano-sheets in an aqueous solution and filtering the solution with the assistance of a vacuum pump to remove the water and create GO paper.…”

Section: Introductionmentioning

confidence: 99%

Open-source micro-tensile testers via additive manufacturing for the mechanical characterization of thin films and papers

et al. 2018

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The cost of specialized scientific equipment can be high and with limited funding resources, researchers and students are often unable to access or purchase the ideal equipment for their projects. In the fields of materials science and mechanical engineering, fundamental equipment such as tensile testing devices can cost tens to hundreds of thousands of dollars. While a research lab often has access to a large-scale testing machine suitable for conventional samples, loading devices for meso- and micro-scale samples for in-situ testing with the myriad of microscopy tools are often hard to source and cost prohibitive. Open-source software has allowed for great strides in the reduction of costs associated with software development and open-source hardware and additive manufacturing have the potential to similarly reduce the costs of scientific equipment and increase the accessibility of scientific research. To investigate the feasibility of open-source hardware, a micro-tensile tester was designed with a freely accessible computer-aided design package and manufactured with a desktop 3D-printer and off-the-shelf components. To our knowledge this is one of the first demonstrations of a tensile tester with additively manufactured components for scientific research. The capabilities of the tensile tester were demonstrated by investigating the mechanical properties of Graphene Oxide (GO) paper and thin films. A 3D printed tensile tester was successfully used in conjunction with an atomic force microscope to provide one of the first quantitative measurements of GO thin film buckling under compression. The tensile tester was also used in conjunction with an atomic force microscope to observe the change in surface topology of a GO paper in response to increasing tensile strain. No significant change in surface topology was observed in contrast to prior hypotheses from the literature. Based on this result obtained with the new open source tensile stage we propose an alternative hypothesis we term ‘superlamellae consolidation’ to explain the initial deformation of GO paper. The additively manufactured tensile tester tested represents cost savings of >99% compared to commercial solutions in its class and offers simple customization. However, continued development is needed for the tensile tester presented here to approach the technical specifications achievable with commercial solutions.

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3D-printed slit nozzles for Fourier transform microwave spectroscopy

Cited by 27 publications

References 38 publications

Microwave Study of Triflic Acid Hydrates: Evidence for the Transition from Hydrogen-Bonded Clusters to a Microsolvated Ion Pair

Microwave Study of Triflic Acid Hydrates: Evidence for the Transition from Hydrogen-Bonded Clusters to a Microsolvated Ion Pair

Microwave spectrum and structure of the 3,5-difluoropyridine⋯CO2 van der Waals complex

Open-source micro-tensile testers via additive manufacturing for the mechanical characterization of thin films and papers

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