For a standard model of patchy colloidal fluids with patch number M = 2, where chain formation (polymerization) occurs, we show that Wertheim theory predicts critical behavior at vanishing density and temperature. The analysis is based on determining lines in the phase diagram of maximal correlation length and compressibility. Simulation studies identify the latter line and confirm our prediction of Fisher–Widom crossover, i.e., the asymptotic decay of the pair correlation function changes from monotonic to damped oscillatory as the density is increased. For M > 2, it is known that phase separation occurs with a true critical point. Our results support the notion that a “disappearing” critical point occurs in the limit M = 2 and we uncover its remnants.

中文翻译：

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链状斑块液中消失的临界点的残留物

对于斑块编号为M = 2的斑块状胶体流体的标准模型，其中发生链形成（聚合反应），我们表明Wertheim理论预测了在消失的密度和温度下的临界行为。该分析基于确定最大相关长度和可压缩性的相图中的线。仿真研究确定了后者，并证实了我们对Fisher-Widom交叉的预测，即，随着密度的增加，对相关函数的渐近衰减从单调变为阻尼振荡。对于M > 2，已知相分离发生在真正的临界点处。我们的结果支持这样的观点：临界点M = 2中出现了“消失的”临界点，我们发现了它的残余物。