Fourier Transform Ion Mobility Measurement of Chain Branching in Mass-Selected, Chemically Trapped Oligomers from Methylalumoxane-Activated, Metallocene-Catalyzed Polymerization of Ethylene

2007 ◽  
Vol 129 (10) ◽  
pp. 2796-2802 ◽  
Author(s):  
Rolf Dietiker ◽  
Fabio di Lena ◽  
Peter Chen
Keyword(s):  
Fourier Transform ◽  
Ion Mobility ◽  
Chain Branching ◽  
Mobility Measurement ◽  
Catalyzed Polymerization

scholarly journals Improving Ion Mobility Measurement Sensitivity by Utilizing Helium in an Ion Funnel Trap

2014 ◽  
Vol 86 (11) ◽  
pp. 5295-5299 ◽  
Author(s):  
Yehia M. Ibrahim ◽  
Sandilya V. B. Garimella ◽  
Aleksey V. Tolmachev ◽  
Erin S. Baker ◽  
Richard D. Smith
Keyword(s):  
Ion Mobility ◽  
Measurement Sensitivity ◽  
Funnel Trap ◽  
Mobility Measurement ◽  
Ion Funnel

Ion mobility spectrometry: a review. Part 1. Structural analysis by mobility measurement

The Analyst ◽  
2004 ◽  
Vol 129 (11) ◽  
pp. 984 ◽  
Author(s):  
Colin S. Creaser ◽  
John R. Griffiths ◽  
Claire J. Bramwell ◽  
Sadaf Noreen ◽  
Carol A. Hill ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Ion Mobility Spectrometry ◽  
Ion Mobility ◽  
Mobility Measurement

Apodization functions in Fourier transform ion mobility spectrometry

1992 ◽  
Vol 64 (2) ◽  
pp. 171-177 ◽  
Author(s):  
Robert H. St. Louis ◽  
William F. Siems ◽  
Herbert H. Hill
Keyword(s):  
Fourier Transform ◽  
Ion Mobility Spectrometry ◽  
Ion Mobility

Gaseous ion mobility measurement: N2H+ in helium and argon at 295 K

1982 ◽  
Vol 89 (5) ◽  
pp. 443-445 ◽  
Author(s):  
T.T.C. Jones ◽  
J.D.C. Jones ◽  
K. Birkinshaw ◽  
N.D. Twiddy
Keyword(s):  
Ion Mobility ◽  
Mobility Measurement

scholarly journals Fourier transform ion mobility spectrometry with multinozzle emitter array electrospray ionization

RSC Advances ◽  
2017 ◽  
Vol 7 (13) ◽  
pp. 7836-7842 ◽  
Author(s):  
Hongling Shen ◽  
Xu Jia ◽  
Qingyan Meng ◽  
Wenjie Liu ◽  
Herbert H. Hill
Keyword(s):  
Fourier Transform ◽  
Electrospray Ionization ◽  
Ion Mobility Spectrometry ◽  
Ion Mobility ◽  
Duty Cycle ◽  
Ion Current ◽  
Square Wave ◽  
Emitter Array

Fourier transform ion mobility spectrometry (FT-IMS) is a useful multiplexing method for improving the duty cycle (DC) of IMS from 1 to 25% when using an entrance and exit ion gate to modulate the ion current with a synchronized square wave chirp.

Characterisation of Long Chain Branching (LCB) in Polyolefins and Elastomers Using Large Amplitude Oscillatory Shear (LAOS) and Fourier Transform Rheology Using Harmonics of the Stress Signal

2002 ◽  
Author(s):  
Henri G. Burhin
Keyword(s):  
Molecular Weight ◽  
Fourier Transform ◽  
Production Control ◽  
Average Molecular Weight ◽  
Signal Distortion ◽  
Chain Branching ◽  
Long Chain Branching ◽  
Fourier Transform Rheology ◽  
Stress Signal ◽  
Long Chain

It is difficult, if not impossible to quantify LCB in polymers using rheological test methods only. Most of the reported rheological methods are affected by polymer characteristics other than LCB (Molecular weight Distribution (MWD), polymer microstructure, polymer type etc…). Poly-Propylene samples having different level of LCB produced by reactive extrusion with Per-Oxi-Dicarbonate have been characterised at strain ratios between 2.5 and 10. Stress signal distortion has been found to be sensitive only to the presence and level of LCB and not to Average Molecular Weight (AMW) and MWD. Quantification of the signal distortion was performed using Fourier transform rheology. As linear visco-elasticity equations are not applicable to LAOS, the approach of Giacomin and Dealy was applied. This considers the stress signal as a Fourier series and enables the calculation of G′n and G″n. LCB has a strong effect on both G′n and G″n, on their ratio and especially on G′ from the first harmonic (G′1). Repeatability data (CV) on G′1 and G″1 shows excellent sensitivity (<1%). The technique has been successfully applied to commercially available elastomers (BR and EPDM) enabling comparisons based on LCB level irrespectively of the AMW and MWD. Rapid graphical differentiation between linear and non linear polymers is achieved with stress/strain rate curves (Lissajou figure). The development of this technique provides polymer suppliers and their customers the ability to rapidly assess variations in Long Chain Branching, essential for incoming material and/or production control.

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