Question

In general, ____-cell foams allow water to move through the wall more easily then _____-cell foams.

A) Dense, porous.
B) Flexible, rigid.
C) Insulated, uninsulated.
D) Hard, soft.

Answer 1

Porous-cell foams have cell walls with hydrophilic and porous structures that allow for easy movement of water, while dense-cell foams have walls that resist water absorption due to their tensile strength.

Step-by-step explanation:

In general, porous-cell foams allow water to move through the wall more easily than dense-cell foams. Cell walls that are hydrophilic and have a porous structure, such as those with matrix polymers (e.g., pectins, hemicellulose), allow for the high permeability and low resistance to the movement of water. This characteristic is primarily due to the cohesion and adhesion of water molecules to the carbohydrate components of the cell wall. In contrast, cell walls that are dense and have components such as cellulose or chitin microfibrils offer more resistance to water due to their tensile strength and their ability to resist water absorption.