Preferably, the ultrasound is applied at acidic pH.

A pressure sensitive adhesive which is dispersible at an alkaline pH but not at an acidic or a neutral pH is disclosed.

PHluorin: pH-sensitive GFP, turns off at acidic pH.

Exemplary formulations include one or more acid pH modulator

The final composition is highly effective even at acidic pH values (pH < 7) and has an enhanced non-stringy texture.

– A pH that respects the skin, meaning an acid pH:

The controlled conditions include use of acidic pH for the derivatisation step and a higher pH for purification.

An apparatus comprises: an anode formed of graphene oxide from an acidic pH; a cathode from a pH greater than the acidic pH of the anode; and charge collectors deposited on the anode and the cathode.

The weakly basic polymers are water-soluble and cationic at acidic pH, but neutral in charge at basic pH.

In one embodiment, the invention's compositions have an acidic pH.

The pH of witch hazel is between 3.0 and 5.0 (acidic pH).

The medium is kept at an acidic pH, and an electrical current is applied.

The composition is capable of fibrillary aggregation upon subjection to acidic pH Thus a pre-fibril composition is provided that has a variety of uses.

The graft copolymers do not swell / dissolve at neutral and basic pH and swell / dissolve at acidic pH.

An acidic pH will promote the oxidation of your jewel.