The Acidity of Bound Wood Acid: A New Method for Determining the Acidity of Insoluble Acids

Balaba, W. M.; Subramanian, R. V.

doi:10.1515/hfsg.1984.38.6.309

Cited by 4 publications

(2 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…c pH dependent adhesion forces between COOH-tips and COOH-spruce pH dependent adhesion behavior can be explained by attractive forces at low pH towards protonated COOHtips and repulsive forces towards the ionized COO -tips at high pH on the wood surface. The pK a value of COOH-modified fir wood was reported to be 5.75 (Balaba and Subramanian 1984), which is lower than the pK a of the COOH-spruce in our study. It was reported that the pK a value of a dispersion of microfibrillated cellulose rods was depending on the ionic strength of the dispersion (the pK a value shifted from 7.4 at 1 mM to 5.3 at 300 mM) assuming a typical pK a value of 4.8 for carboxyl groups (Wa ˚gberg et al 2008).…”

Section: Force Titration Of Native and Chemically Modified Wood Cell Wallscontrasting

confidence: 89%

“…For instance, contact angle measurements are applied to calculate the surface free energy and for the determination of its acid and basic components (Gindl and Tschegg 2002 ; Gindl et al 2004 ). In another method, the p K a value of modified wood is identified by recording the pH of a solvent, in which wood flakes were stored (Balaba and Subramanian 1984 ). Mechanical disintegration of wood allows further possibilities to analyze the surface behavior.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Local force titration of wood surfaces by chemical force microscopy

et al. 2021

View full text Add to dashboard Cite

Chemical force microcopy, a variation of atomic force microscopy, opened the door to visualize chemical nano-properties of various materials in their natural state. The key function of this method is given by translating adhesion forces between a functionalized tip and the sample to chemical surface behavior. In force titration, these adhesion forces are studied in different pH buffers, which allows estimating the pKa value of the analyzed surface. Herein, we report the use of this method to study natural and chemically treated wood surfaces, which are of interest in sustainable material design. First, we show varying adhesion phenomena of OH- and COOH-functionalized tips on native spruce wood cells. Then, we demonstrate how peak force tapping with chemically functionalized tips can be used to estimate the pKa value of gold substrates (pKa ≈ 5.2) and different wood cell wall layers with high spatial resolution. Additionally, the swelling behavior of wood samples is analyzed in varying pH buffers. With the applied method, chemical surface properties of complex natural substrates can be analyzed. Graphical abstract

show abstract

Section: Force Titration Of Native and Chemically Modified Wood Cell Wallscontrasting

confidence: 89%