Pathway control in the self-construction of complex precipitation forms in a Cu(II)-oxalate system

Abstract

Text AbstractBackground: Many biological systems contain complex precipitation patterns. These structures are considered to be the result of finely tuned and genetically encoded developmental pathways. The amount of encoded information needed to generate and manipulate these structures is poorly understood. Investigating the dynamics of spontaneous pattern formation in non-biological systems provides insights to the physio-chemical phenomena that biological systems must have harnessed for living systems and that modern scientists need to understand for complex nano-technological applications. Results: Here we show that highly complex, precipitation patterns similar to those found in biological systems can be formed in simple Cu(II)-oxalate systems. In these Cu(II)-oxalate systems, structures are constructed by a hierarchy of multiple processes that are precisely self-organized in space and time to form interconnected causal networks that generate complex and diverse structures dependent on construction trajectories that can be controlled by minor variations of initial conditions. Conclusions: Highly complex precipitation patterns similar to those found in biological systems can be generated without a correspondingly complex set of instructions. Our result has implications for understanding early biotic systems that existed prior to the evolution of sophisticated genetic machinery. From an applications perspective, processes and structures that occur spontaneously are the building blocks for novel system chemistry based technologies where products are self-constructed. We also provide a simple model of chemical system that generates biomimetic structures for the study of fundamental processes involved in chemical self-construction.

The impact of reaction rate on the formation of flow-driven confined precipitate patterns

“…Although the characterisation of such crystals does not fall into the scope of this study, we note that those were identified as Na 2 Cu(C 2 O 4 ) 2 Á2H 2 O in a similar system. 26 To see whether a pattern different from the annular one can be achieved in the case of the chosen transition metals when dissolution is excluded, reverse injection experiments were also performed. In these situations, the solution of the transition metal ions was pumped into the host oxalate solution; the patterns observed at Q = 1 mL min À1 flow rate are presented in Fig.…”

Self-organization of calcium oxalate by flow-driven precipitation

“…10,11 Gravity current plays an important role in the emergence of a copper oxalate precipitate pattern characterized by radial lines along which precipitate sedimentation occurs. 12,13 As the dense solution containing copper ions is pumped into the sodium oxalate solution through an inlet, it spreads on the bottom of the dish. The circular symmetry of the precipitate will, however, be broken since the tip of the gravity current is hydrodynamically unstable.…”