Figure 2
From: Rheoreversible hydrogels in paper restoration processes: a versatile tool
PCA analysis. Projection of samples onto the space spanned by the first two principal components (PCs): (A) filter paper; (B-D) filter paper treated with PEO hydrogel for 15, 30 and 45 minutes; (E-F) filter paper treated with PLU hydrogel for 15 and 45 minutes; (G) filter paper loaded with linseed oil; (H) filter paper loaded with linseed oil and treated with PEO hydrogel; (I) filter paper loaded with linseed oil and treated with PLU hydrogel.