## 1 Introduction  
Nowadays, great industrial and academic interests are focused on the design of hybrid nanocomposite materials because they exhibit fascinating properties when inorganic and organic nascent compounds are ingeniously combined [1, 2, 3, 4, 5]. These hybrid materials can be engineered in such a way that could bring about electrical, optical, magnetic, or mechanical properties [6, 7, 8, 9] while displaying various morphologies, including spherical, raspberry-like, snowman-like, or hollow microspheres [10, 11, 12, 13]. Thus, these materials are successfully used in diverse application fields such as electronics, optics, biomedicine, catalysis, cosmetics, adsorption, and separation processes [14, 15, 16]. Several methods have been developed to prepare hybrid nanocomposites, such as seed emulsion polymerization, sol-gel preparation, or surfactant-free emulsion polymerizations [17, 18, 19]. Nevertheless, Pickering emulsion polymerization has been recognized as a facile route for the synthesis of hybrid materials, as it allows combining intimately two nascent compounds that provide extraordinary properties with the composite materials [20, 21]. Contrary to classical emulsions stabilized by surfactants, Pickering emulsions are stabilized by solid nanoparticles, which anchor at the oil-water (O-W) interface, forming a rigid barrier around the dispersed droplets, which makes them highly resistant to coalescence [22, 23]. For this reason, Pickering stabilizers have been used to stabilize high-internal-phase emulsions (HIPE) to prepare highly porous hybrid materials, via polymerization of the continuous phase, with the aim of replacing surfactants, as they can modify the final material properties during their further handling [24; 25]. In Pickering emulsion polymerizations, the inorganic nanoparticles do interact with the growing oligomers and these interactions are predominant in the material design since they control the morphology, structure, and properties of the final hybrid nanomaterials [26; 27; 28]. Two main polymerization mechanisms have been reported to define the basis of stabilization in Pickering emulsions, which are related to the hydrophobic and hydrophilic nature of the initiator used in the reaction [29]. In the presence of a hydrophilic initiator such as ammonium persulfate (APS) or potassium persulfate (KPS), it has been reported that the homogeneous coagulative mechanism represents the dominating mechanism in Pickering emulsion polymerization, and it leads to the formation of submicronic polymer particles [29; 30; 31; 32]. However, when a hydrophobic initiator such as 2,2\({}^{\prime}\)-azobis(2-methylpropionitrile) (AIBN) is used, the polymerization is initiated inside the monomer droplets and micrometric latex particles are formed [29; 31; 33]. However, the mechanisms of polymerization are not so straightforward, and supplementary parameters must be considered, especially the nature of the inorganic nanoparticles, charge, aggregation state, functionalization, and wettability, which can be tuned by adsorption or grafting of organic molecules onto the surface of inorganic nanoparticles [28; 34]. These variables are predominant in the polymerization process, as the inorganic nanoparticles directly interfere in the nucleation and coagulation processes, at the early stage of reaction [28; 35; 36; 37]. During polymerization via the homogeneous coagulative mechanism, the affinity between the inorganic nanoparticles and the polymer matrix is usually provided by modifying the surface of the inorganic nanoparticles with organic functionalizing agents or by means of electrostatic attractions. For instance, [PERSON] et al. [38] reported the polymerization of styrene in the presence of surface-modified silica nanoparticles by a poly(ethylene glycol) monomethyl ether methacrylate (PEGMA)-based macromonomer. The affinity of the inorganic nanoparticles was provided by copolymerization of styrene with the PEGMA chains adsorbed onto the nanoparticles. [PERSON] et al. [39] and [PERSON] et al.