Chemiosomotic flow in a soft conical nanopore: harvesting enhanced blue energy

Abstract

The salinity gradient energy or the ‘blue energy’ is one of the most promising inexpensive and abundant sources of clean energy, having immense capabilities to serve modern-day society. In this...

Salinity Gradient-Induced Power Generation in Nanochannels: The Role of pH-Sensitive Polyelectrolyte Layers

“…Now, considering the reaction of functional group (−COOH) with H + -ion in PEL: −COOH ↔ −COO – + H + and − normalN normalH 3 + ↔ − normalN normalH 2 + normalH + ; we can write the expression of σ PEL (in C/m 3 ) as , σ normalP normalE normalL = 10 18 F N normalA [ − K A Γ A K A + false[ normalH + false] + Γ B K B + false[ normalH + false] ] / t p Here, normalΓ normalA = normalΓ − normalC normalO normalO normalH + normalΓ − normalC normalO normalO − and …”

“…Now, the Nernst–Planck equation for ionic species transport can be written as normal∇ · J⃗ ± = 0 Here, the total ionic flux of cation and anion ( J⃗ i ) due to the contribution of diffusion, electromigration, and convection, is presented as , J⃗ i = prefix− ( D i ∇⃗ c i + z i F c i true( D i normalR normalT ∇⃗ ( ψ ) true) ) + boldu⃗ c i Here, i = 1, 2, 3 and 4 used for salt cation, salt anion, H + , and OH – ions, respectively.…”

“…Note that the voltage difference is less than E diff as some amount of potential drop is instigated by R pore . Hence, we get the expression as: , V normalp normalo normalr normale = E normald normali normalf normalf − I normalp normalo normalr normale R normalp normalo normalr normale …”

“…Now, the maximum pore current will be open circuit current ( I OS = E diff / R pore ) when external load is zero, and the open circuit current can be expressed as , I normalO normalS = prefix∫ F ( ∑ i = 1 4 z i J⃗ i ) · boldn .25em normald s Here, d s is the elemental cross-sectional area for 100 nm width of the nanochannel.…”

“…The direction of the pH- and salinity gradient altogether has a significant impact on power generation as well, demonstrating comparative production of higher power in co-direction conditions than the reverse direction configurations . It is worth mentioning here that the impact of the pH-tunable polyelectrolyte layers (PEL) on blue energy harvesting inside the nanopore has also been investigated recently …”