TUNNELING AND TUNNELING SWITCHING DYNAMICS IN PHENOL AND ORTHO-D-PHENOL: FTIR SPECTROSCOPY WITH SYNCHROTRON RADIATION AND THEORY

Author Institution: Physical Chemistry, Eth ZUrich, Ch-8093 ZUrich, Switzerland; SWISS LIGHT SOURCE, PAUL-SCHERRER-INSTITUTE, CH-5232; Villigen, SwitzerlandThe understanding of tunneling in chemical reactions in \emph{Handbook of High Resolution Spectroscopy}, Vol.~1(Eds. M. Quack and F. Merkt), Wiley, Chicester (2011), 659-722.} is of fundamental interest. A particularly intriguing recent development is the theoretical prediction of tunneling switching in ortho-D-phenol (C$_6$H$_4$DOH) as opposed to phenol (C$_6$H$_5$OH) \textbf{2013}, \emph{52}, 346-349.} where only tunneling dominates the dynamics. For ortho-D-phenol at low energy, tunneling is completely suppressed due to isotopic substitution, which introduces an asymmetry in the effective potential including zero point energy. This localizes the molecular wavefunction in either the syn or the anti structure of ortho-D-phenol. At higher torsional states of ortho-D-phenol, tunneling becomes dominant, thus switching the dynamics to a delocalized quantum wavefunction. Therefore, we have investigated the rotationally resolved THz and IR spectra of phenol and ortho-D-phenol measured with our FTIR setup at the Swiss Light Source (SLS), \textbf{2007}, \emph{8}, 1271-1281, S. Albert, K. Keppler Albert and M. Quack, \emph{High Resolution Fourier Transform Infrared Spectroscopy} in \emph{Handbook of High Resolution Spectroscopy}, Vol.~2 (Eds. M. Quack and F. Merkt), Wiley, Chicester \textbf{2011}, 965-1021, S. Albert, K.K. Albert, Ph. Lerch and M. Quack, \emph{Faraday Discussions} \textbf{2011}, \emph{150}, 71-99.} using synchrotron radiation. We have been able to analyse the torsional fundamentals, the first and second overtones of both isotopomers. A comparison of the spectra of phenol and ortho-D-phenol indicates the theoretically predicted behavior of tunneling switching upon excitation of the torsional mode. In detail, we shall discuss the splitting of the torsional fundamental, of its first and second overtones of phenol as well as the fundamentals of syn- and anti- ortho-D-phenol and the possible tunneling switching in the torsional overtone region of ortho-D-phenol. The results shall be also discussed in relation to the quasiadiabatic channel Reaction Path Hamiltonian approach \textbf{2011}, \emph{150}, 130-132.}. We shall also discuss the comparison with results for meta-D-phenol

Effects of channel surface finish on blood flow in microfluidic devices

The behaviour of blood flow in relation to microchannel surface roughness has been investigated. Special attention was focused on the techniques used to fabricate the microchannels and on the apparent viscosity of the blood as it flowed through these microchannels. For the experimental comparison of smooth and rough surface channels, each channel was designed to be 10mm long and rectangular in cross-section with aspect ratios of ⠥100:1 for channel heights of 50 and 100μm. Polycarbonate was used as the material for the device construction. The shims, which created the heights of the channels, were made of polyethylene terephthalate. Surface roughnesses of the channels were varied from Rz of 60nm to 1.8μm. Whole horse blood and filtered water were used as the test fluids and differential pressures ranged from 200 to 5000Pa. The defibrinated horse blood was treated further to prevent coagulation. The results indicate that a surface roughness above an unknown value lowers the apparent viscosity of blood dramatically due to boundary effects. Furthermore, the roughness seemed to influence both water and whole blood almost equally. A set of design rules for channel fabrication is also presented in accordance with the experiments performed

Effects of channel surface finish on blood flow in microfluidic devices

The behaviour of blood flow in relation to microchannel surface roughness has been investigated. Special attention was focused on the techniques used to fabricate the microchannels and on the apparent viscosity of the blood as it flowed through these microchannels. For the experimental comparison of smooth and rough surface channels, each channel was designed to be 10mm long and rectangular in cross-section with aspect ratios of ⊵100:1 for channel heights of 50 and 100μm. Polycarbonate was used as the material for the device construction. The shims, which created the heights of the channels, were machined from poly(ethylene terephthalate). Surface roughnesses of the channels were varied from Rz of 60nm to 1.8μm. Whole horse blood and filtered water were used as the test fluids and differential pressures ranged from 200 to 5000 Pa. The defibrinated horse blood was further treated to prevent coagulation. The results indicate that a roughness above an unknown value lowers the apparent viscosity of blood dramatically due to boundary effects. Furthermore, the roughness seemed to influence both water and whole blood almost equally. A set of design rules for channel fabrication is also presented in accordance with the experiments performed. ©EDA Publishing/DTIP 2009

Effects of channel surface finish on blood flow in microfluidic devices

The behaviour of blood flow in relation to microchannel surface roughness has been investigated. Special attention was focused on the techniques used to fabricate the microchannels and on the apparent viscosity of the blood as it flowed through these microchannels. For the experimental comparison of smooth and rough surface channels, each channel was designed to be 10mm long and rectangular in cross-section with aspect ratios of ⊵100:1 for channel heights of 50 and 100μm. Polycarbonate was used as the material for the device construction. The shims, which created the heights of the channels, were machined from poly(ethylene terephthalate). Surface roughnesses of the channels were varied from Rz of 60nm to 1.8μm. Whole horse blood and filtered water were used as the test fluids and differential pressures ranged from 200 to 5000 Pa. The defibrinated horse blood was further treated to prevent coagulation. The results indicate that a roughness above an unknown value lowers the apparent viscosity of blood dramatically due to boundary effects. Furthermore, the roughness seemed to influence both water and whole blood almost equally. A set of design rules for channel fabrication is also presented in accordance with the experiments performed. ©EDA Publishing/DTIP 2009