Temperature dependence of pyrolysed sol-gel planar waveguide parameters

Saini, Sajan; Kurrat, R.; Prenosil, J. E.; Ramsden, Jeremy J.

doi:10.1088/0022-3727/27/6/009

Cited by 15 publications

(10 citation statements)

References 10 publications

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“…The N TM ( t ) and N TE ( t ) values for the adsorption−desorption sequences were inserted into the two-mode equations characterizing propagation of the guided light in a four-layer structure with four isotropic layers: support (S), waveguiding film (F), glycoprotein adlayer (A), and cover (C) . Corrections for the varying temperature of the S and F layers were made according to the procedures outlined in ref . The equations were solved to yield the thickness and refractive index of the protein adlayer.…”

Section: Methodsmentioning

confidence: 99%

Temperature Dependence of Mucin Adsorption

Yakubov

Ramsden

2008

Langmuir

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The kinetics of adsorption and desorption on a silica-like surface of the large glycoprotein mucin have been measured across a range of temperatures from 25 to 60 degrees C. The area occupied per molecule diminishes with increasing temperature both in the bulk and adsorbed states, implying that the glycoprotein belongs to the "natively open" conformational class. Due to the conformational rearrangement, the specific interaction energy governing desorption greatly increases with temperature, resulting in an impressively regulated temperature-invariant dynamic surface coating.

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Section: Methodsmentioning

confidence: 99%

Temperature Dependence of Mucin Adsorption

Yakubov

Ramsden

2008

Langmuir

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“…It was observed that the temperature response slightly varies between the individual waveguides, although the general trend is always the same and relative changes in the waveguide properties are very similar. As indicated by Saini et al (1994), the change in the waveguide thickness can be attributed to thermal dilatation of the waveguide material.…”

Section: Deposition At Elevated Temperaturesmentioning

confidence: 98%

“…75453.41 ∆T + 2340.431 ∆T 2 + 6.363191 ∆T 3 10 7 T + 65.7081 × 10 7 Saini et al (1994) where Saini et al (1994) situ by light scattering without any sampling procedure.…”

Section: Refractive Index Parametermentioning

confidence: 99%

Effects of temperature and concentration on mechanism and kinetics of thermally induced deposition from coffee extracts

2014

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Production of soluble (instant) coffee powders typically involves extraction of roasted coffee by water followed by evaporation in order to concentrate extracts before spray or freeze drying to produce dry coffee powder. In the course of evaporation, deposition of dissolved material from coffee extracts is a major cause of fouling at the heat exchange surfaces of evaporators. Therefore, in order to improve the design and optimization of evaporation processes of coffee extracts, better understanding of the deposition mechanism and kinetics is needed. In this study, optical waveguide lightmode spectroscopy (OWLS) was used to monitor the initial formation of nanometer scale deposits on surfaces exposed to coffee extracts. OWLS measurements were complemented by light scattering from extract solutions, gravimetry of macroscopic deposits, and scanning electron microscopy imaging of deposited layers. Primary molecular-scale layers of about 1 mg m^−2 were rapidly formed in the first stage of deposition, even at ambient temperature, followed by the secondary deposition with kinetics strongly dependent on temperature. Secondary deposition rates were low and largely independent of the extract concentration at ambient temperature, but became strongly dependent on the extract concentration at elevated temperatures. In particular, activation energies for the deposition between 25◦C and 70◦C were much higher for the original extract (13.3 mass %, solids) than for diluted extracts (up to 1.3 mass %, solids). Furthermore, heating of the original extracts above 60◦C resulted in rapid aggregation of suspended macromolecules into large clusters, while only gradual aggregation was observed in diluted extracts

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“…With a typical flow rate in the range of microliters per second this usually means milliliters of solutions. Furthermore, given that OWLS (and DPI several orders of magnitude more so) is sensitive to changes in temperature and pH [47,89], it is critical to ensure that these parameters are the same for a subsequently introduced sample as those for the sample to be replaced. Moreover, some flow-through cuvettes might be inappropriate for working with mammalian cell suspensions due to geometrical issues; according to our experience, cells can adhere and aggregate in the immediate vicinity of the inlet aperture (before the sensing area), rather than being uniformly distributed on the entire bottom of the cuvette.…”

Section: Fluidic Systems With Flow-through Cuvettesmentioning

confidence: 99%

“…Another possibility is to incorporate a bubble trap into the fluidic setup [47]. Although the inner part of the bubble trap contains multiple arcs in which the sample is guided, we found that it has no undesirable mixing properties.…”

mentioning

confidence: 94%