Failure to replicate long-range tunable attractions in colloidal system

TL;DR

This paper critically reexamines a reported long-range attraction in colloidal systems, finds inconsistencies in the original data, and concludes that the observed melting phenomena are due to non-equilibrium effects rather than true equilibrium attractions.

Contribution

The study challenges previous claims of temperature-sensitive long-range attractions in colloids, providing reanalysis and experimental evidence that these phenomena are non-equilibrium effects.

Findings

Inconsistencies found in original radial distribution functions and pair potentials.

Failed to reproduce the reported long-range attractions.

Melting phenomena are caused by non-uniform temperature, not equilibrium attractions.

Abstract

Recently, a temperature-sensitive long-range attraction colloidal system exhibiting melting and pre-melting of colloidal crystals has been reported by Li et al.[1]. If it is true, it would be an ideal system to simulate a board range of phase transitions happening in atomic systems. We have reanalyzed their data in [1] and have discovered great inconsistency in their radial distribution functions g(r) and pair potentials u(r). We have tried to reproduce their experimental results but failed to find the temperature-sensitive long rang attraction as reported by Li et al. Based on our experimental observations, We conclude that the melting and premelting reported in their paper are non-equilibrium phenomena caused by non-uniform temperature in the samples of Li et al..