Yu-Ting Lin

The limited water solubility and environmental instability of natural pesticidal compounds impede their broader agricultural use. This study reports an amphiphile-assisted nanoprecipitation method to imbibe azadirachtin-rich neem seed extract (NSE) within a glycine carrier matrix, yielding a stable nanocomposite biopesticide. The formulation, prepared using polyoxyethylene sorbitan monooleate as a stabilizer and glycine as the matrix former, followed by lyophilization, exhibited a hydrodynamic diameter of ∼8 nm when redispersed in water. This glycine nanopesticide (GNP) significantly improved the photostability of azadirachtin under UV-AB irradiation (2000 μW/cm²); spectrophotometric analysis revealed a 27.7% reduction in photodegradation over a 4 day period compared to unformulated NSE powder demonstrated dialysis-based in vitro release assay showed sustained release, with 68.2 ± 2.1% released over 7 days, fitting an exponential model with a time constant of 37.6 h. Contact bioassays against Spodoptera frugiperda larvae revealed enhanced larvicidal potency. LC₅₀ values showed a 1.5- to 6.6-fold improvement compared to unformulated NSE over 11 days. On day 7, GNP had an LC₅₀ of 0.13 mg/mL, compared to 0.86 mg/mL for NSE powder. The nanoformulation also improved wettability on tomato leaves, reducing the contact angle from 99.0° ± 1.6° (DI water) to ∼60° at a concentration of 100 mg/mL GNP. This approach offers a practical method for improving the stability, delivery, and efficacy of hydrophobic biopesticides.

Identifying the descriptors for the synergistic catalytic activity of bifunctional oxide-zeolite catalysts constitutes a formidable challenge in realizing the potential of tandem hydrogenation of CO₂ to hydrocarbons (HC) for sustainable fuel production. Herein, we combined CH₃OH synthesis from CO₂ and H₂ on In₂O₃ and methanol-to-hydrocarbons (MTH) conversion on HZSM-5 and discerned the descriptors by leveraging the distance-dependent reactivity of bifunctional In₂O₃ and HZSM-5 admixtures. We modulated the distance between redox sites of In₂O₃ and acid sites of HZSM-5 from milliscale (∼10 mm) to microscale (∼300 μm) and observed a 3-fold increase in space-time yield of HC and CH₃OH (7.5 × 10^-5 mol_C g_cat^-1 min^-1 and 2.5 × 10^-5 mol_C g_cat^-1 min^-1, respectively), due to a 10-fold increased rate of CH₃OH advection (1.43 and 0.143 s^-1 at microscale and milliscale, respectively) from redox to acid sites. Intriguingly, despite the potential of a three-order-of-magnitude enhanced CH₃OH transfer at a nanoscale distance (∼300 nm), the sole product formed was CH₄. Our reactivity data combined with Raman, Fourier transform infrared (FTIR), and X-ray photoelectron spectroscopy (XPS) revealed the occurrence of solid-state-ion-exchange (SSIE) between acid sites and In^δ+ ions, likely forming In₂O moieties, inhibiting C-C coupling and promoting CH₄ formation through CH₃OH hydrodeoxygenation (HDO). Density functional theory (DFT) calculations further revealed that CH₃OH adsorption on the In₂O moiety with preadsorbed and dissociated H₂ forming an H-In-OH-In moiety is the likely reaction mechanism, with the kinetically relevant step appearing to be the hydrogenation of the methyl species. Overall, our study revealed that efficient CH₃OH transfer and prevention of ion exchange are the key descriptors in achieving catalytic synergy in bifunctional In₂O₃/HZSM-5 systems.

Stimuli-responsive materials are increasingly needed for the development of smart electronic, mechanical, and biological devices and systems relying on switchable, tunable, and adaptable properties.

Viscosity modifying agents are one of the most critical components of hydraulic fracturing fluids, ensuring the efficient transport and deposition of proppant into fissures.