Wood-Water Interactions

Chapter 1: Why is water in wood so important? • All wood properties depend on it, durability, biorefinery, basically everything. • Swelling & shrinkage (could go really deep into this or keep it at non-deep level) • Consequences of moisture: o Swelling shrinkage from micro to macro scale o Effect on mechanical properties o Durability aspects Chapter 2: Why is water in wood so weird? • Discussion of properties of water, water is weird. o Vapor pressure, relative humidity, etc. and methods of measurement o Ideal gas equation and real gas behavior in brief o Water- changes of state • Introduce concepts such as enthalpy, water activity, chemical potential • Discussion of hydrogen bonds • Talk about water in trees, how that impacts water in wood Chapter 3: Where can water go in wood? • Talk about cell wall water, overhygroscopic region, etc • Explain moisture content • Talk about density, specific gravity, basic specific gravity, etc. • (surface forces, hydrogen bonding, etc.) • Relation between basic material properties (density) and moisture sorption in the two moisture ranges • Hydroxyl accessibility • Capillary absorption/Kelvin equation Chapter 4: How much water can wood hold? • Maximum total amount of water wood can hold • Introduce the concept of a sorption isotherm, temperature dependence of isotherm, Clausius-Clapeyron equation • Isotherm models have been used to interpolate data; caution is needed when using them to attempt to derive physical quantities. • Introduce hysteresis • FSP and maximum cell wall moisture – definitions, sorting out the different claimed FSP states • Property Intersection Point (aka fiber saturation point) o Mechanical properties o Dimensions o Electrical properties • Maximum cell wall water content o Experimental methods (DSC, low field NMR, solute exclusion) Chapter 5: How water moves in wood • Sorption kinetics • Wood drying • Liquid water absorption, • Combine liquid vapor transport • Cup tests • transport under non-isothermal conditions (e.g. thermal gradients), Chapter 6: How can we change wood-water relations and why we might want to • Wood modifications often affect how wood interacts with moisture • Why modifications that affect wood-moisture interactions can be beneficial o Improved dimensional stability o More decay resistant • What we know about how different wood modifications affect wood-moisture relations o Bulking modifications o Cross-linking modifications Chapter 7: How can we “see” water in wood? • Mass changes • D2O exchange • Experimental methods for probing capillary water • Neutron scattering • (could include basic equipment such as moisture meters as well as advanced experimental methods used in science • Molecular dynamics simulations • sorption calorimetry, solution calorimetry, isothermal calorimetry, introduce heat of wetting Chapter 8: What is unknown about water in wood? • White paper about what we hope to inspire future researchers to accomplish End Matter: 1. Section on nomenclature 2. Glossary of important terms and our definitions for key things in wood-moisture relations