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Odlyha M. Cohen N. S. Foster G. M. Aliev A. Verdonck E. Grandy D. 《Journal of Thermal Analysis and Calorimetry》2003,71(3):939-951
DMA and solid state 13C NMR techniques were used to measure historical parchment samples within the framework of the project (MAP) Micro Analysis
of Parchment (EC contract No. SMT4-96-2101) in collaboration with the School of Conservation in Copenhagen. DMA was used in
both thermal scan and creep modes. Thermal scans provided information on the transitions associated with the collagen polymer.
Microthermal analysis was also used to obtain information on the topography and thermal conductivity of sample areas of 100
μm. Localised heating enabled measurements of softening transitions in the sample. This behaviour is influenced by the chemical
composition of parchment. 13C NMR provided information on the carbon atoms associated with the polypeptide chains of the collagen
in parchment. The behaviour of samples immersed in water and measured in DMA creep mode was used to measure the shrinkage
behaviour of the parchment samples. The different but complementary techniques provided a means for characterising the physicochemical
state of parchment samples.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
2.
Identification of collagen-based materials that are supports of cultural and historical objects 总被引:1,自引:0,他引:1
Budrugeac P. Miu L. Popescu C. Wortmann F.-J. 《Journal of Thermal Analysis and Calorimetry》2004,77(3):975-985
The TG, DTG, DTA methods were used for investigation of the thermal degradation in static air atmosphere of some collagen-based
materials (some sorts of collagen, recent manufactured parchments and tanned leathers, patrimonial (historical) leathers).
At the progressive heating, all investigated materials exhibit two main successive processes, associated with the dehydration
and thermo-oxidative degradation. The patrimonial leathers were divided in two groups, namely: a group containing the majority
of the analyzed materials, for which the rates of the thermo-oxidation process are substantially lower than those corresponding
to the recent manufactured leathers, and a group for which the rates of thermo-oxidation process are closed to those corresponding
to the recent manufactured leathers. Consequently, if by the thermal analysis in air atmosphere of a leather sample, a value
of the rate of the thermo-oxidation process smaller than that corresponding to the recent manufactured leathers is obtained,
then the analyzed leather is a patrimonial one. The reciprocal statement of this qualitative criterion for distinction between
recent manufactured leather and patrimonial leather is not valid. The DSC analyses of collagen-based materials were performed
in air (DSC(air)) and in water (DSC(water)). The denaturation process takes place at lower temperatures in water than in air.
Unlike recent manufactured leathers and parchments, each patrimonial leather exhibits on DSC(water) plot 2-4 peaks. Consequently,
the number of peaks from DSC(water) curve could be another qualitative criterion for distinction between a recently manufactured
leather and a patrimonial leather.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
3.
The hyphenated thermal analysis-mass spectrometry
technique (TA-MS) was applied for the investigation of the thermal behavior
of reference and aged parchment samples. The kinetic parameters of the process
were calculated independently from all recorded TA and MS signals. The kinetic
analysis showed the distinct dependence of the activation energy on the reaction
progress. Such behavior is characteristic for the multistage mechanism of
the reaction.
The comparison of the kinetic parameters calculated
from the different signals i.e. TG, DSC, MS for H2O,
NO and CO2, however, indicated that they were differently
dependent on the aging of the sample. For the parchment samples, the aging
almost does not change the kinetics of the decomposition calculated from the
DSC data: the influence of aging seems to be too negligible to be detected
by these techniques. On the other hand, the much more sensitive mass spectrometric
technique applied to the kinetic analysis allowed monitoring of visible changes
in the thermal behavior of the parchment samples due to the aging process.
The influence of aging was especially visible when the MS signals of water
and nitric oxide were applied for the determination of the kinetic parameters.
The applied method of the kinetic analysis allowed also the prediction
of the thermal behaviour of reference and aged parchment samples under isothermal
and modulated temperature conditions. Presented results have confirmed the
usefulness of thermoanalytical methods for investigating behaviour of such
complicated systems as leather or parchment. 相似文献
4.
Detection of polydimethylsiloxanes transferred from silicone‐coated parchment paper to baked goods using direct analysis in real time mass spectrometry
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Andreas Jakob Elizabeth A. Crawford Jürgen H. Gross 《Journal of mass spectrometry : JMS》2016,51(4):298-304
The non‐stick properties of parchment papers are achieved by polydimethylsiloxane (PDMS) coatings. During baking, PDMS can thus be extracted from the silicone‐coated parchment into the baked goods. Positive‐ion direct analysis in real time (DART) mass spectrometry (MS) is highly efficient for the analysis of PDMS. A DART‐SVP source was coupled to a quadrupole‐time‐of‐flight mass spectrometer to detect PDMS on the contact surface of baked goods after use of silicone‐coated parchment papers. DART spectra from the bottom surface of baked cookies and pizzas exhibited signals because of PDMS ions of the general formula [(C2H6SiO)n + NH4]+ in the m/z 800–1900 range. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
5.
G. Della Gatta E. Badea R. Ceccarelli T. Usacheva A. Maši? S. Coluccia 《Journal of Thermal Analysis and Calorimetry》2005,82(3):637-649
Summary Environmental impact on parchment was investigated by differential scanning calorimetry (DSC) and scanning electron microscopy
(SEM). Parchments subjected to accelerated ageing and old parchments were compared to evaluate quality and extent of deterioration.
Stability of fibrillar collagen within parchment was determined from the changes in thermodynamic parameters associated with
thermal denaturation. Parchment surface was characterised, and specific morphological criteria were selected for damage assessment.
The thermodynamic and morphological changes of collagen induced by deterioration are discussed, and their correlations are
proposed as a means of ranking damage in old parchments.</o:p> 相似文献
6.
To reveal the fire injuring of parchment, the changes in the thermal behaviour of some goat parchments, obtained from skins
originating from different animals, as a result of thermal aging were determined by thermal analysis methods (DSC; simultaneous
TG/DTG, DSC; micro hot table (MHT)). Thermal aging of parchments was revealed to bring about the decrease in shrinkage temperature,
absolute value of enthalpy of denaturation in water and some changes in non-isothermal parameters characteristic for dehydration
process in static air atmosphere.
The results obtained by DSC analysis performed in N2 and O2 flows as well as those obtained by simultaneous TG/DTG, DSC analyses have shown that both softening (melting) process parameters
and parameters of thermo-oxidative processes have not been changed by thermal ageing. The results obtained by thermal analysis
methods were correlated with those obtained by microscopic investigation of parchment samples immersed in water and scanning
electron microscopy (SEM). The application of these microscopic techniques has revealed the morphology changes in the investigated
parchments as a result of thermal degradation. 相似文献
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