Monitoring nanobubble nucleation at early‐stage within a sub‐9 nm solid‐state nanopore

Abstract

Monitoring nanobubble nucleation at early-stage within a sub-9 nm solid-state nanopore Nanobubble nucleation study is important for understanding the dynamic behavior of nanobubble growth, which is instructive for the nanobubble applications. Benefiting from nanopore fabrication, herein, we fabricated a sub-9 nm SiN X nanopore with the comparable size to nanobubbles at early-stage. The confined nanopore interface serves as a generator for producing nanobubbles by the chemical reaction between NaBH 4 and H 2 O and as an ultra-sensitive sensor for monitoring the H 2 nanobubble nucleation process. By carrying out the NaBH 4 concentration-dependent experiments, we found the life-time of nanobubbles decreased 250 times and the frequency of nanobubble generation increased 38 times with the NaBH 4 concentration increasing from 6 to 100 mM. The long-time equilibrium between gas molecules inward flux and outward flux could prolong the life-time of nanobubbles to hundreds of milliseconds at low NaBH 4 concentration. The raw current trace depicted that the transient accumulation and dissolution of cavity occurred during all the life-time of nanobubbles. Therefore, the sub-9 nm SiN X nanopore shows a strong ability for real-time monitoring the nanobubble nucleation at early-stage with high temporal and spatial resolution. This work provides a guide to study the dynamic and stochastic characteristics of nanobubbles.

CO2‐NBs‐ assisted enzymatic hydrolysis as a new green approach for extraction of phenolic compounds from rhizomes of Polygonatum cyrtonema Hua

“…Bubble nucleation occurs when dissolved gases in liquids become supersaturated. Recent molecular dynamics simulations have revealed that gas molecules firstly form cavities less than 1 nm in diameter during the initial nucleation phase, and under high local gas supersaturation, two or more cavities coalesce to generate nascent NBs (Li et al ., 2020). The formation of NBs not only influenced by the presence of a large number of gases but also the type of gas, thus impacting the process (Bunkin et al ., 2021).…”

Single-Digit Nanobubble Sensing via Nanopore Technology

“…In contrast, nanopore technology, founded on the principle of passing molecules through a minuscule pore, presents a novel approach to nanobubble sensing. This method offers high sensitivity, single-molecule precision, real-time monitoring, and label-free features, − providing a promising alternative for nanobubble detection.…”

“…As reported in the literature, when nanobubbles are generated by chemical reactions inside a nanopore, a single nanopore has the capability to monitor nanobubble nucleation in the early stages and characterize the size growth, up to several hundred nanometers. ,, In the case of bulk nanobubbles naturally existing in a solution, an average bubble size of 100 nm has been quantified but the nanobubbles possess diameters of only several nanometers in acidic solution. , Notably, research has demonstrated the detection of single-digit-sized nanobubbles, generated through processes like laser heating or the hydrophobicity of nanochannels, using nanopore technology. , …”

Electrochemical Generation of Individual Nanobubbles Comprising H2, D2, and HD

“…11 Moreover, the stable bubbles formed can be interrogated (e.g., to determine their internal pressure) 20 in contrast to, e.g., resistive-pulse techniques, which form unstable bubbles that are constantly growing. 24 The chemical similarities between the isotopes of hydrogen (H and D) present an opportunity to study the nucleation and properties of bubbles of two very similar gases (H 2 and D 2 ), including studying kinetic isotope effects on the rate of stochastic nucleation processes. Herein, we compare the electrogeneration of individual D 2 and H 2 nanobubbles from the electroreduction of D + and H + , respectively, determining that D 2 bubbles form at higher dissolved gas concentrations (0.28 vs 0.23 M).…”

“…While the nucleation of single bubbles has been driven by plasmon-induced heating, such measurements are restricted to the study of vapor bubbles (where the gas has the same identity as the solvent) . Moreover, the stable bubbles formed can be interrogated (e.g., to determine their internal pressure) in contrast to, e.g., resistive-pulse techniques, which form unstable bubbles that are constantly growing …”