Fig. 2From: Enhanced rates of enzymatic saccharification and catalytic synthesis of biofuel substrates in gelatinized cellulose generated by trifluoroacetic acidLoss of birefringence upon treatment with TFA as determined by darkfield microscopy (upper panels) compared to gel forms observed by differential interference contrast (DIC) microscopy (lower panels). a Never-dried samples in water. b Freeze-dried. Times are hours of heating at 55 °C following low-temperature swelling at − 20 °C for 15 hBack to article page