Anionic clays or layered double hydroxides (LDHs) form a broad class of materials, defined by the characteristic lamellar structure with two kinds of metal cations in the layers and anionic species in the interlayer region . Despite LDHs being known since 19 th century and first synthetic LDHs developed in 1940s , there is recent significant growth in scientific and practical interest in these inexpensive structured materials. Due to the relative ease of modification of their composition, a significant variation in functional performance can be attained, which is highly attractive in many application areas, especially in environmental catalysis, sustainable technologies, including healthcare technologies . Modulation of properties is typically achieved by modification of the feed composition in the controlled co-precipitation batch synthesis methods. Batch synthesis results in materials with broad variability in their functional properties and very poor reproducibility . Even minute changes to synthesis parameters (pH, concentrations, rates of addition, duration, temperature and amount of water during aging, method of washing) from one preparation to the next result in vast differences in the final material's properties: for example, Wang et al demonstrated that morphology, pore structure and chemical composition are highly sensitive to pH of co-precipitation; Climent et al showed that crystal size of similar materials is highly sensitive to temperature of the solutions during precipitation. More generally in the liquid phase synthesis of nanomaterials, the impact of process conditions on the outcomes of synthesis of crystalline materials is not well characterised due to the fast rates of precipitation and complex mechanisms of crystal growth and aggregation. As a result, it is very challenging to develop detailed structure-property relationships of LDHs that would enable rational design of new LDH-based functional nanomaterials, and applications of these materials in novel sustainable technologies are hindered by lack of reproducibility of material properties at scale. This limitation of the co-precipitation synthesis at scale stems from the fundamental mismatch of the rates of nucleation and crystal growth and aggregation, and the rates of mixing in stirred vessels. It is impossible to attain a uniform distribution of concentrations within a reaction vessel under such conditions; this automatically leads to a broad distribution in the properties of the obtained materials and poor reproducibility in manufacture. We hypothesised that achieving reproducible outcome in the co-precipitation step is critically important for attaining a narrow distribution of properties of the final LDHs in the two-step synthesis method. Although there are several reports of LDH synthesis under continuous flow conditions using micro-scale and meso-scale reactors , there are no studies detailing systematic characterizations of morphological properties and thermal stability of the produced materials. In most of the earlier studies the produced materials are characterized by broad particle size distribution.