Due to its versatile potential applications, nanofluidic devices have drawn much attention of researches in various fields. Among these, pressure-driven power generation is considered as a candidate for the next generation alternative green energy source, and pressure-driven ion separation (nanofiltration) for desalination. Aiming to achieve a better performance in these two representative cases, a cylindrical nanopore having different types of non-uniform surface charge profile is adopted, and its performance under various conditions assessed. We show that lower the surface charge density near the nanopore inlet region can suppress the effect of ion concentration polarization (ICP) and improve the selectivity, thereby enhancing appreciably its power generation performance. For a fixed averaged surface charge density, if the bulk salt concentration is low, the higher the surface charge density near the nanopore openings, the better its performance. The degree of ICP can be alleviated by applying a sufficiently large pressure difference. Although previous studies showed that salt rejection is influenced significantly by the profile of the electric field inside a nanopore, we find that the electric field at nanopore openings also plays a role. Through choosing appropriately the surface charge profile, it is possible to solve the trade-off between rejection and flow rate.

由于其广泛的潜在应用，纳米流体装置引起了各个领域的研究的广泛关注。其中，压力驱动发电被认为是下一代替代绿色能源的候选者，压力驱动离子分离（纳滤）用于海水淡化。为了在这两种代表性情况下获得更好的性能，采用了具有不同类型的非均匀表面电荷分布的圆柱形纳米孔，并对其在各种条件下的性能进行了评估。我们表明，降低纳米孔入口区域附近的表面电荷密度可以抑制离子浓差极化（ICP）的影响并提高选择性，从而显着提高其发电性能。对于固定的平均表面电荷密度，如果本体盐浓度低，纳米孔开口附近的表面电荷密度越高，其性能越好。通过施加足够大的压力差可以减轻ICP的程度。尽管先前的研究表明脱盐率受到纳米孔内电场分布的显着影响，但我们发现纳米孔开口处的电场也起作用。Through choosing appropriately the surface charge profile, it is possible to solve the trade-off between rejection and flow rate. 尽管先前的研究表明脱盐率受到纳米孔内电场分布的显着影响，但我们发现纳米孔开口处的电场也起作用。Through choosing appropriately the surface charge profile, it is possible to solve the trade-off between rejection and flow rate. 尽管先前的研究表明脱盐率受到纳米孔内电场分布的显着影响，但我们发现纳米孔开口处的电场也起作用。Through choosing appropriately the surface charge profile, it is possible to solve the trade-off between rejection and flow rate.