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Měření aktivit - KEMS
1…Furnace
(0.1 – 20 K min-1,
25-1450ºC)
2…QMS
range 1-512 amu
resolution 0,5amu
IE = 25 -100 eV
3…Turbomolecular Pump
4…TA System Controller (TASC)
5..Vacuum Controller, (cca 9·10-6
mbar)
6…QMS Controller
7..Purification Column (oxygen)
(Argon 99,999)
Mass Flow Controller
(MFC)
Knudsen cell / mass spectroscopy
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Princip
http://www.kip.uni-heidelberg.de/AG_Pucci/Research/LaboratoryAstrophysics/Experiments/Evaporation/Evaporation.php
Kinetická teorie plynů:
dm/dt… hm. Ztráta (mikrováhy)
W0…Clausiusův pravděpod. faktor (0-1)
projití otvorem, α…pravděp.
Kondenzace (pro kovy=1)
Whitman-Motzfeld equation
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STA 409
CD/3/403/5/G -
detaily
Iontový zdroj
DSC držák na vzorek
Iontový zdroj
Knudsenova
komůrka
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MS detekce
více složek
pj = (Ijk
+ T) / Sjk
aj = Pj(A) / Pj(R) =
[Ijk
+(A)·T)] /
[Ijk
+(R)·T)] · [Sjk(R)] /
[Sjk(A)] = [Ijk
+(A)] /
[Ijk
+(R)]
Parciální tlak:
Aktivita
složky:
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Praktické provedení
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Termomechanická
analýza (TMA)
ICTAC: A technique in which a deformation of the
sample under non-oscillating stress is monitored
against time or temperature while the temperature
of the sample, in a specified atmosphere, is
programmed. The stress may be compression,
tension, flexure or torsion.
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Variace mechanického namáhání
Hlavní použití:
Polymery
použití
Method Mode Measured
Quantity
As a function of Information
Obtained
Bulk sample Flat probe/light
load
expansion Temperature Coefficient of Expansion
and Tg
Divided sample Dilatometer Volumetric
changes
Temperature Coefficient of
expansion and Tg
Thin film Penetration
probe/
Significant load
Depth of
penetration
Force Modulus,
Cross-link
densityTime Creep behaviour
Cure behaviour
Temperature Softening (Tg)
Melting
Film or fibre Tension
accessory
Uniaxial
extension or
shrinkage
Force Modulus,
Cross-link
densityTime Creep behaviour,
Cure behaviour
Temperature Tg, melting,
Cure behaviour,
Prepn. History
Fluid Parallel plates Distance Time Viscosity,
Gelation
Temperature Melting,
Viscosity,
Gelation
Bulk or
supported
Flexure
accessory
Bending Time Creep behaviour
Temperature Softening (Tg)
Melting
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Přístroje
ASTM E831
Linseis
Dilatometer Netzsch 402
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Kalibrace na teplotu
Mnohonásobný sendwič z čistých kovů
In
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Aplikace
Určení teploty skelného přechodu Tg PTFE
Velké zatížení
malé zatížení
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Reaktivita
GI Storage
modulus
GII Loss modulus
Uvolnění -
_COOCH3
ramen
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TBA
Vznik HCl
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Dynamická mechanická analýza
• A technique in which the sample's kinetic properties are analyzed by
measuring the strain or stress that is generated as a result of strain or
stress, varies (oscillate) with time, applied to the sample.
• Static Viscoelasticity Measurement
A technique in which the change in stress or strain is measured under
uniform stress or strain that remains constant across time.
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Cyklické zatížení (Tg)
•Metler TMA/STDA841e
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Diskuse