During a protein spray drying process, thermal and mechanical stresses are exerted on the proteins leading to degradation. We hypothesize that in situ measurements of the droplet size, temperature distribution inside droplets and UV fluorescence will provide degradation kinetics.
Final Report Abstract
The investigation of denaturation and degradation of proteins in the spray drying process with the help of optical techniques in single droplet experiments require theoretical understanding of light scattering by a multilayered droplet in a laser beam. To describe laser beams of interest, transverse model Bessel beams and a general description of circularly symmetric Bessel beams provide insight of the light scattering and its interaction with droplet. Drying a protein droplet results in a radially inhomogeneous droplet. The internal field distribution of such multilayered droplet is also investigated because it would be of interest in fluorescence thermography considered to check our rainbow thermography. To improve on the size resolution of interferometric particle imaging, phase interferometric particle imaging technique is developed to investigate nanoscale size changes. In first drying stage, the size change, evaporation rate and temperature profile of deionized water and whey protein isolate of various concentrations have been investigated by using two single droplet experimental techniques including the free fall or free moving and the glass filament technique. In free fall or free moving technique, results show that the size change, evaporation rate and temperature profile have been determined accurately using phase interferometric particle imaging and rainbow refractometry. However, the observation time was restricted to 25 milliseconds. Within this short time interval, the position of the rainbow and hence the temperature profile remained constant. To increase the drying time, the glass filament technique is used and droplets of 80-90 µm are levitated on a silicon carbide fiber of 15 µm diameter. The investigation shows that in drying time of 100 milliseconds, a size change of 18-20 µm is observed. There is also a change of the scattering angle of rainbow position and hence a transient temperature profile is deduced. However, due to some discrepancies in droplet trajectory and levitation point of droplet used for calibration, the temperature profile has some error. Using a droplet generator, which can produce a droplet of relatively large size of 150 µm and uniform trajectory, the error in temperature profile could be removed.
Publications
- General description of circularly symmetric Bessel beam of arbitrary order. Journal of Quantitative Spectroscopy & Radiative Transfer 184 (2016) 218-232
Jia Jie Wang, Thomas Wriedt, James A. Lock, Lutz Mädler
(See online at https://doi.org/10.1016/j.jqsrt.2016.07.011) - General description of transverse model Bessel beams and construction of basis Bessel fields. Journal of Quantitative Spectroscopy & Radiative Transfer 195 (2017) 8-17
Jia Jie Wang, Thomas Wriedt, James A. Lock, Young Chang Jiao
(See online at https://doi.org/10.1016/j.jqsrt.2016.10.010) - Multipole expansion of circularly symmetric Bessel beams of arbitrary order for scattering calculations. Optics Communications 387 (2017) 102-109
Jia Jie Wang, Thomas Wriedt, Lutz Mädler, Yi Ping Han, Peter Hartmann
(See online at https://doi.org/10.1016/j.optcom.2016.11.038) - Phase interferometric particle imaging for simultaneous measurements of evaporating micronsized droplet and nanoscale size changes. Appl. Phys. Lett. 111, 041905 (2017)
Yingchun Wu, Haipeng Li, Marc Brunel, Jia Chen, Gérard Gréhan, Lutz Mädler
(See online at https://doi.org/10.1063/1.4996363) - Internal field distribution of a radially inhomogeneous droplet illuminated by an arbitrary shaped beam. Journal of Quantitative Spectroscopy & Radiative Transfer 210 (2018) 19-34
Jia Jie Wang, Thomas Wriedt, Yi Ping Han, Lutz Mädler, Young Chang Jiao
(See online at https://doi.org/10.1016/j.jqsrt.2018.02.012) - Simultaneous measurement of monocomponent droplet temperature/refractive index, size and evaporation rate with phase rainbow refractometry. Journal of Quantitative Spectroscopy & Radiative Transfer 214 (2018) 146-157
Yingchun Wu,Cyril Crua, Haipeng Li, Sawitree Saengkaew, Lutz Mädler, Xuecheng Wu, Gérard Gréhan
(See online at https://doi.org/10.1016/j.jqsrt.2018.04.034) - Rainbow pattern analysis of a multilayered sphere for optical diagnostic of a heating droplet. Optics Communications 441 (2019) 113-120
Jianxi Zhou, Yuan Fang, Jia Jie Wang, Le Zhu, Thomas Wriedt
(See online at https://doi.org/10.1016/j.optcom.2019.02.061)
