A new method for the study of calcium carbonate growth on steel surfaces

The growth of calcium carbonate crystals on a steel surface, known as scali ng, has been investigated. A heat exchanger cell was built for this purpose , and the crystals formed on the surface were examined in a scanning electr on microscope. Two surface active polymers with a diphosphate end group, di ffering in hydrophobic/hydrophilic ratio, were synthesized. The effect on c rystal formation of addition of these polymers was studied. Both polymers d ecreased the amount of calcium carbonate deposition on the surface. When th e experiment started at low pH the polymers promoted the formation of very symmetrical spheres of calcium carbonate, ranging from 1 to 10 mum in size. When the experiment was started at neutral pH only amorphous calcium carbo nate was obtained on the steel surface. (C) 2001 Elsevier Science B.V. All rights reserved.