Nanomaterials 2022 , 12 , 790
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C-CMF R-CMF R-CNF E-CNF
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Velocity gradient, G (s -1 )
Figure3. Gel point vs. stirring speed.
100 125 150
0 25 50 75
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Velocity gradiant G, (s -1 )
C-CMF (CN)
R-CMF (CN)
R-CNF (CN)
E-CNF (CN)
C-CMF (EMT)
R-CMF (EMT)
R-CNF (EMT)
E-CNF (EMT)
Figure4. Aspect ratio of the four hydrogels at different stirring speed according to Crowding Number (CN) and Effective Medium Theory (EMT) theories. To explain the possible modifications on the CMF/CNF suspensions with the agitation, the AR is calculated by the Equations (3)–(6) to obtain the relationship between both parameters, using the two theories, CN and EMT, and setting the AR as the independent variable according to Equations (7) and (8). Figure 4 shows AR values of the four hydrogels at the different stirring speed conditions using both theories. In this figure, the AR of C-CMF, R-CMF, and R-CNF stirred at high stirring speed was possible to be graphed although with a large accuracy error, so its representation is drawn in black. AR ( EMT )= 3.61 · ⎛ ⎝ ∅ g kg m 3 1000 ⎞ ⎠ − 0.567 (7) AR ( CN )= 5.98 · ⎛ ⎝ ∅ g kg m 3 1000 ⎞ ⎠ − 0.5 (8) In all hydrogels studied, AR has a similar trend with a maximum at intermediate stirring speeds. At low agitations, water and hydrogel are hardly mixed, but the crossed
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