Evaporative cooling of microscopic water droplets <i>in vacuo</i>: Molecular dynamics simulations and kinetic gas theory

Schlesinger, Daniel; Sellberg, Jonas A.; Nilsson, Anders; Pettersson, Lars G. M.

doi:10.1063/1.4944387

Cited by 24 publications

(22 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A microscope was used to estimate the droplet diameter in situ (95 μm), the droplet spacing (285 μm), and the velocity (~12 m s −1 ). The droplet temperature was estimated as described elsewhere 27 , 31 using the Knudsen theory of evaporation, which has in addition been confirmed by MD simulations 69 . For reaching higher temperatures, the jet was used in a continuous mode (not droplet mode) with a dispenser with diameter 100 μm and was used under Helium environment at atmospheric pressure.…”

Section: Methodsmentioning

confidence: 86%

Coherent X-rays reveal the influence of cage effects on ultrafast water dynamics

et al. 2018

Self Cite

View full text Add to dashboard Cite

The dynamics of liquid water feature a variety of time scales, ranging from extremely fast ballistic-like thermal motion, to slower molecular diffusion and hydrogen-bond rearrangements. Here, we utilize coherent X-ray pulses to investigate the sub-100 fs equilibrium dynamics of water from ambient conditions down to supercooled temperatures. This novel approach utilizes the inherent capability of X-ray speckle visibility spectroscopy to measure equilibrium intermolecular dynamics with lengthscale selectivity, by measuring oxygen motion in momentum space. The observed decay of the speckle contrast at the first diffraction peak, which reflects tetrahedral coordination, is attributed to motion on a molecular scale within the first 120 fs. Through comparison with molecular dynamics simulations, we conclude that the slowing down upon cooling from 328 K down to 253 K is not due to simple thermal ballistic-like motion, but that cage effects play an important role even on timescales over 25 fs due to hydrogen-bonding.

show abstract

Section: Methodsmentioning

confidence: 86%

Coherent X-rays reveal the influence of cage effects on ultrafast water dynamics

et al. 2018

Self Cite

View full text Add to dashboard Cite

show abstract

“…The droplets are cooled by evaporation and the temperature is calculated using Knudsen's theory of evaporation and Fourier's law of heat conduction (24,25). This approach to determining droplet temperatures has been proven to be successful in various experimental setups (13,14,26) and has been validated using ME simulations (25). A 2.05-μm infrared (IR) pulse heats the sample, increasing the temperature of the droplets by 0.5-1 K. The droplets are then probed by a femtosecond X-ray pulse after a 1-μs delay time, allowing the liquid to expand.…”

Section: Significancementioning

confidence: 99%

Enhancement and maximum in the isobaric specific-heat capacity measurements of deeply supercooled water using ultrafast calorimetry

Pathak

Späh

Esmaeildoost

et al. 2021

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

Knowledge of the temperature dependence of the isobaric specific heat (Cp) upon deep supercooling can give insights regarding the anomalous properties of water. If a maximum in Cp exists at a specific temperature, as in the isothermal compressibility, it would further validate the liquid–liquid critical point model that can explain the anomalous increase in thermodynamic response functions. The challenge is that the relevant temperature range falls in the region where ice crystallization becomes rapid, which has previously excluded experiments. Here, we have utilized a methodology of ultrafast calorimetry by determining the temperature jump from femtosecond X-ray pulses after heating with an infrared laser pulse and with a sufficiently long time delay between the pulses to allow measurements at constant pressure. Evaporative cooling of ∼15-µm diameter droplets in vacuum enabled us to reach a temperature down to ∼228 K with a small fraction of the droplets remaining unfrozen. We observed a sharp increase in Cp, from 88 J/mol/K at 244 K to about 218 J/mol/K at 229 K where a maximum is seen. The Cp maximum is at a similar temperature as the maxima of the isothermal compressibility and correlation length. From the Cp measurement, we estimated the excess entropy and self-diffusion coefficient of water and these properties decrease rapidly below 235 K.

show abstract

“…Since their temperature depends on the travel time in vacuum, various temperature points could be systematically measured by simply adjusting the distance between the dispenser and the measurement point. The temperature calibration [38,39] and error estimation of our temperature calibration method are described in detail in the SM [26] and in Ref. [25].…”

mentioning

confidence: 99%

Temperature-Independent Nuclear Quantum Effects on the Structure of Water

Kim¹,

Pathak²,

Späh³

et al. 2017

Phys. Rev. Lett.

Self Cite

View full text Add to dashboard Cite

Nuclear quantum effects (NQEs) have a significant influence on the hydrogen bonds in water and aqueous solutions and have thus been the topic of extensive studies. However, the microscopic origin and the corresponding temperature dependence of NQEs have been elusive and still remain the subject of ongoing discussion. Previous x-ray scattering investigations indicate that NQEs on the structure of water exhibit significant temperature dependence [Phys. Rev. Lett. 94, 047801 (2005)PRLTAO0031-900710.1103/PhysRevLett.94.047801]. Here, by performing wide-angle x-ray scattering of H_{2}O and D_{2}O droplets at temperatures from 275 K down to 240 K, we determine the temperature dependence of NQEs on the structure of water down to the deeply supercooled regime. The data reveal that the magnitude of NQEs on the structure of water is temperature independent, as the structure factor of D_{2}O is similar to H_{2}O if the temperature is shifted by a constant 5 K, valid from ambient conditions to the deeply supercooled regime. Analysis of the accelerated growth of tetrahedral structures in supercooled H_{2}O and D_{2}O also shows similar behavior with a clear 5 K shift. The results indicate a constant compensation between NQEs delocalizing the proton in the librational motion away from the bond and in the OH stretch vibrational modes along the bond. This is consistent with the fact that only the vibrational ground state is populated at ambient and supercooled conditions.

show abstract

Evaporative cooling of microscopic water droplets in vacuo: Molecular dynamics simulations and kinetic gas theory

Cited by 24 publications

References 28 publications

Coherent X-rays reveal the influence of cage effects on ultrafast water dynamics

Coherent X-rays reveal the influence of cage effects on ultrafast water dynamics

Enhancement and maximum in the isobaric specific-heat capacity measurements of deeply supercooled water using ultrafast calorimetry

Temperature-Independent Nuclear Quantum Effects on the Structure of Water

Contact Info

Product

Resources

About