Research Article

Approximate Analytical Solution of Nonlinear Reaction’s Diffusion Equation at Conducting Polymer Ultramicroelectrodes

Table 2

Approximate expressions of concentration of substrate, and current under the boundary conditions (12a)–(12c).

ConditionsConcentrations and currentsFigures

For very small values of 𝛼 𝑢 = s i n h ( 𝛾 𝜌 ) 𝜌 s i n h [ 1 𝛾 ] + 𝑣 ( 𝛾 c o s h [ 𝛾 ] s i n h [ 𝛾 ] ) (17)Figures 5 and 6
𝜓 = 𝛾 c o s h [ 𝛾 ] s i n h [ 𝛾 ] s i n h [ 1 𝛾 ] + 𝑣 ( 𝛾 c o s h [ 𝛾 ] s i n h [ 𝛾 ] ) (18)Figure 8

For large values of 𝛼 ( 𝛼 1 ) and all values of 𝛾 𝑢 = 1 + 𝛾 ( 1 2 𝛼 2 𝑣 6 𝛼 𝑣 𝛾 𝑣 2 𝛾 ) 3 6 𝛼 3 𝑣 𝜌 2 2 1 𝑣 + 𝛾 2 1 2 0 𝛼 3 𝜌 4 4 1 𝑣 (20)Figure 7
𝜓 = 𝛾 ( 3 0 𝛼 2 𝑣 1 5 𝛼 𝑣 𝛾 𝑣 5 𝛾 ) 4 5 𝛼 3 𝑣 (21)Figure 9

For small and medium values of 𝛼 and all values of 𝛾 𝑢 = s i n h ( 𝛾 𝜌 ) 𝜌 s i n h [ 1 𝛾 ] + 𝑣 ( 𝛾 c o s h [ 𝛾 ] s i n h [ 𝛾 ] ) 𝛼 𝛾 s i n h ( 𝛾 𝜌 ) 𝜌 s i n h [ 1 𝛾 ] + 𝑣 ( 𝛾 c o s h [ 𝛾 ] s i n h [ 𝛾 ] ) 3 + 𝛼 𝛾 s i n h [ 1 𝛾 ] + 𝑣 ( 𝛾 c o s h [ 𝛾 ] s i n h [ 𝛾 ] ) 2 (22)Figures 5 and 6
𝜓 = 𝛾 c o s h [ 𝛾 ] s i n h [ 𝛾 ] s i n h [ 1 𝛾 ] + 𝑣 ( 𝛾 c o s h [ 𝛾 ] s i n h [ 𝛾 ] ) 𝛼 𝛾 ( 𝛾 c o s h [ 𝛾 ] s i n h [ 𝛾 ] ) s i n h [ 1 𝛾 ] + 𝑣 ( 𝛾 c o s h [ 𝛾 ] s i n h [ 𝛾 ] ) 3 (23)Figure 8