We demonstrate the autonomous synthesis of iron (hydr)oxide (green rust, magnetite, and lepidocrocite) nanoparticles by precipitating iron(II) ions using hydroxide ions generated in situ with the methylene glycol-sulfite (MGS) reaction, a pH-clock. We show that the nature of the products can be predetermined by tuning the initial iron(II) concentration.

We describe a preliminary investigation of the dissolution dynamics of zinc oxide nanoparticles in the presence of cyclic esters (δ-gluconolactone and propanesultone) as slow acid generators. The particles dissolution is monitored by means of turbidimetry and correlated with the evolution of pH over time. The results could be of interest for the design of chemically programmable colloidal systems.

The autonomous activation of acid-autocatalyzed sulfite-halogenate (iodate, bromate, chlorate) reactions is programmed using slow acid generators (δ-gluconolactone GL, and 1,3propanesultone PrS). A remarkable correlation is found between the pH-and temperature-time profiles, especially for the chlorate-sulfite-GL system. Further optimization of the latter resulted in a chemical system able to generate sudden temperature and pH changes after a tailorable induction time, that is a "thermochemical clock".

The addition of silver(I) ions to the methylene glycol-sulphite (MGS) clock reaction results in the sudden formation of metallic silver nanoparticles. Stable suspensions are obtained in presence of poly(vinyl pyrrolidone)....

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