Cellulose Source Tailors the Physical and Structural Properties of Double-Functionalized Aerogels

Figures & data

Figure 1. (A) Bacterial cellulose from HS medium (BC) deconstructed paste, (b) bacterial cellulose from cashew juice permeated (BCP) deconstructed paste, and (c) eucalyptus nanocellulose paste. Nanofibrillated oxidized BC (d), BCP (e), and EC (f) hydrogels.

Figure 2. Schematic diagram of the steps for obtaining cellulose aerogels.

Figure 3. Picture of aerogels from HS medium (BC) (a), bacterial cellulose from cashew juice permeated (BCP) (b), and eucalyptus nanocellulose (EC) (c). Micrography of aerogels: BC (d,g), BCP (e,h), and EC (f,i).

Figure 4. FTIR spectra of oxidized-silanized bacterial cellulose from HS medium (BC), from cashew juice permeated (BCP), and from eucalyptus nanocellulose (EC) aerogels.

Table 1. Average values of apparent density, porosity, shrinkage, maximum compression stress at 50% deformation (σ_MAX, ε_50%), elasticity modulus (E) and final deformation after 24 h of the compression test (ε_FINAL) of BC (bacterial cellulose from the synthetic medium HS), BCP (bacterial cellulose from cashew juice permeate), and EC (eucalyptus nanocellulose) aerogels.

Property	BC	BCP	EC
Apparent density (kg. m^−3)	11.7 ± 0.3^a	11.2 ± 0.6^a	11.2 ± 0.3^a
Porosity (%)	99.3 ± 0.0^a	99.4 ± 0.0^b	99.4 ± 0.0^b
Shrinkage (%)	14.2 ± 1.1^a	19.1 ± 1.5^a.b	23.5 ± 0.2^b
σMAX, ε50%(kPa)	13.0 ± 0.8^a	3.1 ± 0.4^b	3.1 ± 0.2^b
E (kPa)	39.4 ± 2.0^a	3.1 ± 1.4^b	10.7 ± 2.3^b
εFINAL(%)	83.5 ± 0.1^a	85.1 ± 0.2^a	86.9 ± 5.3^a

Note: Values are the mean of two measurements ± standard deviation and means followed by a common superscript letter in the rows are not significantly different by the HSD Tukey’s test at 5% level of significance.

Figure 5. Average values of the contact angle between water and aerogel samples and test images. Means followed by a common letter are not significantly different by the HSD Tukey’s test at 5% level of significance. BC: bacterial cellulose from the synthetic medium HS, BCP: bacterial cellulose from cashew juice permeate, EC: eucalyptus nanocellulose.

Figure 6. a) Absorption capacity of BC aerogels for different organic oils/solvents (means followed by the same lowercase letter for each type of solvent are not significantly different by the HSD Tukey’s test at 5% level of significance), and b) Cycles of ethanol absorption/drying of aerogels. BC: bacterial cellulose from synthetic medium, BCP: bacterial cellulose from cashew juice permeate, EC: eucalyptus nanocellulose.