Measuring volume change from change in mass I want to measure the expansion (by change in volume) of a material in liquid. However the shapes are so complex that I can only measure their mass. Is it possible to compute the volume of the expanded shape by measuring its mass alone?

Given mass $m_0$ at $t_0$ and mass $m_1$  at $t_1$ and the density $\rho_\mathrm m$ of the material and $\rho_\mathrm l$ of the liquid, can I find the volume change of the object from $t_0$ to $t_1$?

One could assume that $(m_0-m_1)/\rho_\mathrm l$ is the correct answer, but I am not sure if this is the right way to go about it?
You can't compute the volume of a solid from the mass alone.

You can measure the specific gravity as a function of the temperature of the liquid. You'd need to know how the density of the liquid changes with temperature to convert the specific gravity data at each temperature to actual density value which could then be used to calculate the effective volume of the solid at each temperate.