Ammonium chloride powder

Abstract Organometal lead halide perovskites have been widely used as the light harvester for high-performance solar cells. However, typical perovskites of methylammonium lead halides (CH 3 NH 3 PbX 3 , X=Cl, Br, I) are usually sensitive to moisture in ambient air, and thus require an inert atmosphere to process. Here we demonstrate a moisture-induced transformation of perovskite crystals in a triple-layer scaffold of TiO 2 /ZrO 2 /Carbon to fabricate printable mesoscopic solar cells. An additive of ammonium chloride (NH 4 Cl) is employed to assist the crystallization of perovskite, wherein the formation and transition of intermediate CH 3 NH 3 X·NH 4 PbX 3 (H 2 O) 2 (X=I or Cl) enables high-quality perovskite CH 3 NH 3 PbI 3 crystals with preferential growth orientation. Correspondingly, the intrinsic perovskite devices based on CH 3 NH 3 PbI 3 achieve an efficiency of 15.6% and a lifetime of over 130 days in ambient condition with 30% relative humidity. This ambient-processed printable perovskite solar cell provides a promising prospect for mass production, and will promote the development of perovskite-based photovoltaics.

Abstract licence: CC BY

Abstract Ammonium (NH 4 + ), a breakdown product of amino acids that can be toxic at high levels, is detected by taste systems of organisms ranging from C. elegans to humans and has been used for decades in vertebrate taste research. Here we report that OTOP1, a proton-selective ion channel expressed in sour (Type III) taste receptor cells (TRCs), functions as sensor for ammonium chloride (NH 4 Cl). Extracellular NH 4 Cl evoked large dose-dependent inward currents in HEK-293 cells expressing murine OTOP1 (mOTOP1), human OTOP1 and other species variants of OTOP1, that correlated with its ability to alkalinize the cell cytosol. Mutation of a conserved intracellular arginine residue (R292) in the mOTOP1 tm 6-tm 7 linker specifically decreased responses to NH 4 Cl relative to acid stimuli. Taste responses to NH 4 Cl measured from isolated Type III TRCs, or gustatory nerves were strongly attenuated or eliminated in an Otop1 −/− mouse strain. Behavioral aversion of mice to NH 4 Cl, reduced in Skn-1a −/− mice lacking Type II TRCs, was entirely abolished in a double knockout with Otop1 . These data together reveal an unexpected role for the proton channel OTOP1 in mediating a major component of the taste of NH 4 Cl and a previously undescribed channel activation mechanism.

Abstract licence: CC BY

Quaternary ammonium compounds (Quats) are a large class of permanently charged cationic chemicals that are used in a variety of consumer and industrial products for their antimicrobial properties. Didecyl dimethyl ammonium chloride (DDAC) and alkyl (C12, C14, C16) dimethyl benzyl ammonium chloride (C12-C16 ADBAC) are frequently used as active ingredients in antimicrobials and are the focus of the current hazard assessment. Robust toxicology databases exist for both DDAC and C12-C16 ADBAC; however, the majority of available studies for DDAC and C12-C16 ADBAC are unpublished, but have been submitted to and reviewed by regulatory agencies (i.e., EPA and European Chemicals Agency) to support antimicrobial product registration. With the objective of contributing to public understanding of the robust and complete toxicology database available for DDAC and C12-C16 ADBAC, a comprehensive review was conducted using available peer-reviewed literature and unpublished data submitted to and summarized by regulatory agencies. A review of available literature indicates that DDAC and C12-C16 ADBAC have similar hazard profiles. Both DDAC and C12-C16 ADBAC are poorly absorbed via the oral and dermal exposure routes (≤10%), are not systemically distributed, and are primarily excreted in feces. DDAC and C12-C16 ADBAC are not dermal sensitizers, are not specific developmental or reproductive toxicants, are not carcinogenic or genotoxic, and do not cause systemic toxicity. DDAC and C12-C16 ADBAC are irritating/corrosive to skin at high concentrations, and are acutely toxic via the oral, dermal (C12-C16 ADBAC only), and inhalation exposure routes; however, both DDAC and C12-C16 ADBAC are considered non-volatile and are not readily aerosolized. Both DDAC and C12-C16 ADBAC can cause toxicity in repeated dose oral toxicity studies with no-observed-adverse-effect levels ranging from 10 to 93.1 mg/kg-day for DDAC and 3.7-188 mg/kg-day for C12-C16 ADBAC in subchronic and chronic studies conducted with beagles, mice, and rats. The toxicological effects associated with reported lowest-observed-adverse-effect levels for both DDAC and C12-C16 ADBAC are consistently characterized by reduced food consumption, reduced mean body weight, reduced body weight gain, and local irritation. These effects are consistent with the mode of action of an irritating/corrosive chemical. Based upon currently available data, the main concern associated with exposure to DDAC and C12-C16 ADBAC is local effects through irritation.

Abstract licence: CC BY-NC-ND