Porous silica particles have shown applications in various technological fields including their use as catalyst supports in heterogeneous catalysis. The mesoporous silica particles have ordered porosity, high surface area, and good chemical stability. These interesting structural or textural properties make porous silica an attractive material for use as catalyst supports in various heterogeneous catalysis reactions. The colloidal nature of the porous silica particles is highly useful in catalytic applications as it guarantees better mass transfer properties and uniform distribution of the various metal or metal oxide nanocatalysts in solution. The catalysts show high activity, low degree of metal leaching, and ease in recycling when supported or immobilized on porous silica-based materials. In this overview, we have pointed out the importance of porous silica as catalyst supports. A variety of chemical reactions catalyzed by different catalysts loaded or embedded in porous silica supports are studied. The latest reports from the literature about the use of porous silica-based materials as catalyst supports are listed and analyzed. The new and continued trends are discussed with examples.

Smart polymers are a special class of polymers, which respond to the various external stimuli by changing their properties. Recent developments in synthetic polymer chemistry have provided the possibility of designing and synthesis of various new stimuli‐responsive polymers. These stimuli‐responsive polymers can be used to prepare smart drug delivery systems (DDS) by grafting them on various nanomaterials. The main aim of this review is to present collective information on various stimuli‐responsive polymers grafted on silica nanoparticles for the preparation of smart DDS. The stimuli covered are pH, temperature, redox, reactive oxygen species (ROS), glucose concentration, enzymes, magnetic field, and so forth. The structures of various stimuli‐responsive polymers are shown with their relevance to the preparation of smart DDS. The crucial roles of macromolecular design and synthesis of smart polymers in the development of stimuli‐responsive DDS are discussed with examples from literature and the challenges that still exist in this area of research are presented.