Polymeric Nano‐Blue‐Energy Generator Based on Anion‐Selective Ionomers with 3D Pores and pH‐Driving Gating

Abstract

Though decades have passed, the nanofluidic system that determines the RED approach process raises fundamental issues about the impact of surface charge on ionic transmembrane property. [5-8] Developments in nanomanufacturing have triggered technological revolutions in nanoporous membrane design and fabrication. [4,9-15] Selecting porous membranes is of the essence for the design of said energy devices. So far, inorganic composite, organic materials, soft matter hydrogel, [16] wood, [17] silk, [18,19] etc. [20-25] have been used to harness salinity gradient energy and have made a giant leap for the applications. Advanced polymers, especially functional ionomers, hold great potential in nanofluid devices because of their unique ion selectivity, uniform 3D pore structure, and physical mechanical properties. [26-28] Ionomers with available chemical diversity could self-assemble into 3D pores by intermolecular phase separation, which bear hydrophilic functional ionic pendants and hydrophobic backbone. [26-29] For decades, ionomers are extensively used as solid electrolytes in electrochemical technologies, especially serving as the Blue energy as a renewable, substantial energy resource has attracted scientists who are interested in discovering abundant membrane materials to achieve high power density. For decades, ionomers have been used as ion-exchange membrane to harvest this energy. Though extensive studies have been conducted, the underlying mechanism of ionic transmembrane behavior is still under debate. Here, the ionic transmembrane properties through membranes with 3D pores prepared by ionomers (polyphenylsulphone with pyridine pendants (PPSU-Py)) are systematically studied. A series of PPSU-Py with tunable porosities and surface charge densities is obtained simply by adjusting the percentages of the pendant. Nanoscale morphologies of the ionomers are simulated with the dissipative particle dynamic method, which is in agreement with the experimental data. Then, nanofluidic behaviors of as-prepared porous membranes are studied, which exhibit anion selectivity, pH gating, and modulated transmembrane conductance. Furthermore, a series of salinity gradient power harvesters based on the ionomers are constructed, of which the output power density is improved by tuning the charge density with the maximum output power density that reaches up to 1.44 W m-2. The impact of the ionomer on nanofluidic behavior is systematically discussed, and it is believed this work will shed light on nanofluidic materials and blue energy generator design.

Highly selective and high-performance osmotic power generators in subnanochannel membranes enabled by metal-organic frameworks

“…S6, the maximum output power density was about 2.96 W/m 2 under this 50-fold NaCl concentration gradient. Note that although the achieved power density is smaller than the above value with using KCl (4.93 W/m 2 ) under the same concentration gradient, it is still higher than all the reported state-of-the-art anion-selective nanochannel membranes ( 14 , 15 , 39 – 41 ) to the best of our knowledge (table S2). The demoted osmotic power when using NaCl can be attributed to the larger hydrated diameter of Na + ions (7.16 Å) than the K + ions (6.62 Å) ( 31 ).…”

Anion‐Selective Layered Double Hydroxide Composites‐Based Osmotic Energy Conversion for Real‐Time Nutrient Solution Detection

“…These membranes are classified into three categories including negatively charged membranes, positively charged membranes, and oppositely charged membranes. [ 6,7,12,16,29,31–37 ]…”

“…These membranes are classified into three categories including negatively charged membranes, positively charged membranes, and oppositely charged membranes. [6,7,12,16,29,[31][32][33][34][35][36][37] channel size and high surface charge density is outstanding correspondingly (Figure S10b, Supporting Information). However, long channel length seems to weaken the energy conversion capability especially for narrow channels.…”

“…f)Comparison of the output performance and energy conversion efficiency with reported nanofluidic membranes in the literature based on the same testing area. These membranes are classified into three categories including negatively charged membranes, positively charged membranes, and oppositely charged membranes [6,7,12,16,29,[31][32][33][34][35][36][37].…”

Nanofluidic osmotic power generators – advanced nanoporous membranes and nanochannels for blue energy harvesting

“…The employment of 3D materials has been proposed as a simple way to obtain membranes with low cost and easy scalability acting as efficient SGE devices. 65,135,184,244,245 The combination of interconnected 3D nanostructured networks together with the high surface and space charge leading to high conductance and selectivity has been identied as determining factors. 246 In the last year, several proofs-of-concept have been introduced in the synthesis, characterization, and energy conversion testing of these materials.…”