2.5. Transmission electron microscopy (TEM)
Drops of dilute cellulose nanofiber suspensions were deposited
into glow-discharged carbon-coated TEM grids. The excess liquid
was absorbed by a piece of filter paper. After the specimen
has been completely dried, it was observed using a FEI Tecnai
G2 electron microscope operated at 80 kV. The diameters of the
cellulose nanofibers were calculated fromTEMimages using microscope
image analysis system (TDY-V5.2, Beijing Tianhong Precision
Instrument Technology Co., Ltd., China), which were used to illustrate
size distributions.