M2pmicrobalance

A PerkinElmer Jade
differential scanning calorimeter was used for this study. The temperature
program cycled twice between 10 and −60 °C with a rate
of 5 °C/min. Paint films (90 μm thickness) were taken out
of the water, patted dry with paper tissue before being cut into small
pieces, and then placed into sealed aluminum DSC pans. The pans were
weighed when empty and after adding the sample to a Sartorius M2P
microbalance. To minimize water evaporating from potentially leaking
pans, the nitrogen flow in the DSC instrument was turned off during
measurements. The aluminum pans were weighed again after the measurement
run to check for water evaporation. This data can be found in Section
E of the Supporting Information.

Measurements of maximum test diameter (μm) and dry test weight (μg) of each individual specimen (n = 3528) were recorded at the end of the experiment. A microbalance (Sartorius M2P Microbalance, with a precision of ±1μg) was employed to weigh foraminiferal tests. The microbalance was tested prior to use over several days in a controlled trial to reduce the error associated with any changes either in temperature, pressure or air flow in the air-conditioned weighing room. Subsequently, using a pre-weighed aluminium capsule, each foraminiferal specimen was individually weighed three times on three different days and its overall average was used for further analysis. Average standard deviations calculated for the three dry weight measurements of foraminiferal tests in each pH treatments are pH 8.1 (+/-0.5 μg); pH 7.9 (+/-0.7 μg), pH 7.7 (+/-0.4 μg) and pH 7.3 (+/-0.9 μg).