Glass transition of partially crystallized gelatin-water mixtures studied by broadband dielectric spectroscopy

By using Broadband Dielectric Spectroscopy with nanostructured silicon electrodes we found that the segmental dynamics (dynamic glass transition) of a series of P2VP brushes is bulk-like.

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Kinetically controlled glass transition measurement of organic aerosol thin films using broadband dielectric spectroscopy

Atmospheric Measurement Techniques ◽

10.5194/amt-11-3479-2018 ◽

2018 ◽

Vol 11 (6) ◽

pp. 3479-3490 ◽

Cited By ~ 7

Author(s):

Yue Zhang ◽

Shachi Katira ◽

Andrew Lee ◽

Andrew T. Lambe ◽

Timothy B. Onasch ◽

...

Keyword(s):

Glass Transition ◽

Dielectric Spectroscopy ◽

Organic Aerosols ◽

Transition Temperatures ◽

Glass Transitions ◽

Relaxation Rates ◽

Heating Rates ◽

Glass Transition Temperatures ◽

Broadband Dielectric Spectroscopy ◽

Kinetically Controlled

Abstract. Glass transitions from liquid to semi-solid and solid phase states have important implications for reactivity, growth, and cloud-forming (cloud condensation nuclei and ice nucleation) capabilities of secondary organic aerosols (SOAs). The small size and relatively low mass concentration of SOAs in the atmosphere make it difficult to measure atmospheric SOA glass transitions using conventional methods. To circumvent these difficulties, we have adapted a new technique for measuring glass-forming properties of atmospherically relevant organic aerosols. Aerosol particles to be studied are deposited in the form of a thin film onto an interdigitated electrode (IDE) using electrostatic precipitation. Dielectric spectroscopy provides dipole relaxation rates for organic aerosols as a function of temperature (373 to 233 K) that are used to calculate the glass transition temperatures for several cooling or heating rates. IDE-enabled broadband dielectric spectroscopy (BDS) was successfully used to measure the kinetically controlled glass transition temperatures of aerosols consisting of glycerol and four other compounds with selected cooling and heating rates. The glass transition results agree well with available literature data for these five compounds. The results indicate that the IDE-BDS method can provide accurate glass transition data for organic aerosols under atmospheric conditions. The BDS data obtained with the IDE-BDS technique can be used to characterize glass transitions for both simulated and ambient organic aerosols and to model their climate effects.

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Kinetic Controlled Glass Transition Measurement of Organic Aerosol Thin Films Using Broadband Dielectric Spectroscopy

10.5194/amt-2017-425 ◽

2018 ◽

Author(s):

Yue Zhang ◽

Shachi Katira ◽

Andrew Lee ◽

Andrew T. Lambe ◽

Timothy B. Onasch ◽

...

Keyword(s):

Glass Transition ◽

Dielectric Spectroscopy ◽

Solid Phase ◽

Organic Aerosols ◽

Transition Temperatures ◽

Glass Transitions ◽

Relaxation Rates ◽

Cooling Rates ◽

Glass Transition Temperatures ◽

Broadband Dielectric Spectroscopy

Abstract. Glass transitions from liquid to semi-solid and solid phase states have important implications for reactivity, growth, and cloud forming (cloud condensation nuclei and ice nucleation) capabilities of secondary organic aerosols (SOA). The small size and relatively low mass concentration of SOA in the atmosphere make it difficult to measure atmospheric SOA glass transitions using conventional methods. To circumvent these difficulties, we have adopted a new technique for measuring glass forming properties of atmospherically relevant organic aerosols. Aerosol particles to be studied are deposited in the form of a thin film onto an interdigitated electrode (IDE) using electrostatic precipitation. Dielectric spectroscopy provides dipole relaxation rates for organic aerosols as a function of temperature (373 to 233 K) that are used to calculate the glass transition temperatures for several cooling rates. IDE-enabled broadband dielectric spectroscopy (BDS) was successfully used to measure the kinetically controlled glass transition temperatures of glycerol and citric acid aerosols with selected cooling rates. The glass transition results agree well with available literature data for these two compounds. The results indicate that the IDE-BDS method can provide accurate glass transition data for organic aerosols under atmospheric conditions. The BDS data obtained with the IDE-BDS technique can be used to characterize glass transitions for both simulated and ambient organic aerosols and to model their climate effects.

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Broadband dielectric spectroscopy for monitoring temperature-dependent chloride ion motion in BiOCl plates

Scientific Reports ◽

10.1038/s41598-020-79018-2 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Adrian Radoń ◽

Dariusz Łukowiec ◽

Patryk Włodarczyk

Keyword(s):

Electrical Conductivity ◽

Dielectric Spectroscopy ◽

Low Frequency ◽

Chloride Ion ◽

Ion Source ◽

Chloride Ions ◽

Ion Concentration ◽

Broadband Dielectric Spectroscopy ◽

Free Chloride ◽

Structure Rebuilding

AbstractThe dielectric properties and electrical conduction mechanism of bismuth oxychloride (BiOCl) plates synthesized using chloramine-T as the chloride ion source were investigated. Thermally-activated structure rebuilding was monitored using broadband dielectric spectroscopy, which showed that the onset temperature of this process was 283 K. This rebuilding was related to the introduction of free chloride ions into [Bi2O2]2+ layers and their growth, which increased the intensity of the (101) diffraction peak. The electrical conductivity and dielectric permittivity were related to the movement of chloride ions between plates (in the low-frequency region), the interplanar motion of Cl− ions at higher frequencies, vibrations of these ions, and charge carrier hopping at frequencies above 10 kHz. The influence of the free chloride ion concentration on the electrical conductivity was also described. Structure rebuilding was associated with a lower concentration of free chloride ions, which significantly decreased the conductivity. According to the analysis, the BiOCl plate conductivity was related to the movement of Cl− ions, not electrons.

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