Impact of Pore–Walls Ligand Assembly on the Biodegradation of Mesoporous Organosilica Nanoparticles for Controlled Drug Delivery

Porous materials with molecular-scale ordering have attracted major attention mainly because of the possibility to engineer their pores for selective applications. Periodic mesoporous organosilica is a class of hybrid materials where self-assembly of the organic linkers provides a crystal-like pore wall. However, unlike metal coordination, specific geometries cannot be predicted because of the competitive and dynamic nature of noncovalent interactions. Herein, we study the influence of competing noncovalent interactions in the pore walls on the biodegradation of organosilica frameworks for drug delivery application. These results support the importance of studying self-assembly patterns in hybrid frameworks to better engineer the next generation of dynamic or “soft” porous materials

Direct Functionalization of Nanodiamonds with Maleimide

Direct Functionalization of Nanodiamonds with Maleimid

Ultralow Self-Doping in Two-dimensional Hybrid Perovskite Single Crystals

Unintentional self-doping in semiconductors through shallow defects is detrimental to optoelectronic device performance. It adversely affects junction properties and it introduces electronic noise. This is especially acute for solution-processed semiconductors, including hybrid perovskites, which are usually high in defects due to rapid crystallization. Here, we uncover extremely low self-doping concentrations in single crystals of the two-dimensional perovskites (C₆H₅C₂H₄NH₃)₂PbI₄·(CH₃NH₃PbI₃)_<i>n</i>−1 (<i>n</i> = 1, 2, and 3), over three orders of magnitude lower than those of typical three-dimensional hybrid perovskites, by analyzing their conductivity behavior. We propose that crystallization of hybrid perovskites containing large organic cations suppresses defect formation and thus favors a low self-doping level. To exemplify the benefits of this effect, we demonstrate extraordinarily high light-detectivity (10¹³ Jones) in (C₆H₅C₂H₄NH₃)₂PbI₄·(CH₃NH₃PbI₃)_<i>n</i>−1 photoconductors due to the reduced electronic noise, which makes them particularly attractive for the detection of weak light signals. Furthermore, the low self-doping concentration reduces the equilibrium charge carrier concentration in (C₆H₅C₂H₄NH₃)₂PbI₄·(CH₃NH₃PbI₃)_<i>n</i>−1, advantageous in the design of p–i–n heterojunction solar cells by optimizing band alignment and promoting carrier depletion in the intrinsic perovskite layer, thereby enhancing charge extraction