scholarly journals Determination of the molar mass of surface-grafted weak polyelectrolyte brushes using force spectroscopy

Polymer ◽  
2015 ◽  
Vol 67 ◽  
pp. 111-117 ◽  
Author(s):  
Ateyyah AL-Baradi ◽  
Michael R. Tomlinson ◽  
Zhenyu J. Zhang ◽  
Mark Geoghegan
Keyword(s):  
Molar Mass ◽  
Force Spectroscopy ◽  
Polyelectrolyte Brushes

scholarly journals Molar mass determination of lignins and characterization of their polymeric structures by multi-detector gel permeation chromatography

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Evamaria C. Gaugler ◽  
Wolfgang Radke ◽  
Andrew P. Vogt ◽  
Dawn A. Smith
Keyword(s):  
Molar Mass ◽  
Lithium Bromide ◽  
Gel Permeation Chromatography ◽  
Mass Determination ◽  
Organosolv Lignin ◽  
Gel Permeation ◽  
Softwood Kraft Lignin ◽  
Polymeric Structures

AbstractMolar masses, Mark-Houwink-Sakurada (MHS) exponents, and refractive index increments (dn/dc) for three lignins were determined without derivatization by multi-detector gel permeation chromatography (GPC) in dimethylformamide (DMF) with 0.05 M lithium bromide (LiBr). The lack of effectiveness of fluorescence filters on molar mass determination by GPC-multi-angle laser light scattering (MALS) was confirmed for softwood kraft lignin (Indulin AT) and revealed for mixed hardwood organosolv lignin (Alcell) as well as soda straw/grass lignin (Protobind 1000). GPC with viscometry detection confirmed that these lignins were present as compact molecules. The MHS exponent α for Indulin AT and Alcell was in the order of 0.1. Additionally, the intrinsic viscosity of Protobind 1000 for a given molar mass was much lower than that of either Alcell or Indulin AT. This is the first report of dn/dc values for these three lignins in DMF with 0.05 M LiBr.

Inter-laboratory evaluation of SEC-post-column calcofluor for determination of the weight-average molar mass of cereal β-glucan

2015 ◽  
Vol 124 ◽  
pp. 254-264 ◽  
Author(s):  
Anne Rieder ◽  
Svein Halvor Knutsen ◽  
Ann-Sissel T. Ulset ◽  
Bjørn E. Christensen ◽  
Roger Andersson ◽  
...  
Keyword(s):  
Molar Mass ◽  
Laboratory Evaluation ◽  
Average Molar Mass

scholarly journals Determination of the Average Molar Mass of the Vapour Above Molten Sodium Chloride by the Transpiration Method.

1979 ◽  
Vol 33a ◽  
pp. 407-412 ◽  
Author(s):  
Halvor Kvande ◽  
Oldrich Strouf ◽  
Pär Svanström ◽  
Elina Näsäkkälä ◽  
Eberhard Hoyer ◽  
...  
Keyword(s):  
Sodium Chloride ◽  
Molar Mass ◽  
Average Molar Mass ◽  
Molten Sodium ◽  
Transpiration Method

Consecutive determination of softwood kraft lignin structure and molar mass from NMR measurements

Holzforschung ◽  
2017 ◽  
Vol 71 (7-8) ◽  
pp. 563-570 ◽  
Author(s):  
Jerk Rönnols ◽  
Anna Jacobs ◽  
Fredrik Aldaeus
Keyword(s):  
Molar Mass ◽  
Industrial Applications ◽  
Size Exclusion ◽  
Ionization Time ◽  
Flight Mass Spectrometry ◽  
Exclusion Chromatography ◽  
Pfg Nmr ◽  
Softwood Kraft Lignin ◽  
Good Agreement

Abstract The general molecular properties and in particular, the molar mass of lignin are of central importance for industrial applications, as these data govern important thermal and mechanical characteristics. The focus of the present paper is pulsed field gradient-nuclear magnetic resonance (PFG-NMR), which is suitable for determination of lignins’ weight-average molar mass, based on diffusion constants. The method is calibrated by lignin fractions characterized by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS). It could be demonstrated on a set of softwood kraft lignins that the PFG-NMR approach gives results in very good agreement with those obtained using conventional size exclusion chromatography (SEC).

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