Polymer Functionalization of Mesoporous Silica Nanoparticles Using Controlled Radical Polymerization Techniques

Abstract

Mesoporous silica nanoparticles (MSNs) are widely studied and are an interesting material due to its application in wide range of areas, for example, in drug delivery, catalysis, in sensors, and in adsorption and separation. Specifically, MSNs contain high surface area and large pore volume, providing high drug loading capacity, tunable pore size, surface chemistry for accommodation of a variety of guest molecules, and versatile functionalization on the external and internal surface for a broad spectrum of applications. Many new strategies have been developed for the synthesis and functionalization of mesoporous silica-based materials. The functionalization of MSNs is highly important as it leads to the development of new chemical and physical properties. Thus, preparation of these organic/inorganic hybrid structures requires facile and controlled techniques to generate enhanced properties. The grafting of polymers using controlled radical polymerization (CRP) techniques has turned out to be the best suited method to synthesize these well-defined organicinorganic hybrid MSNs. Most common polymerization techniques are atom transfer radical polymerization (ATRP), reversible addition-fragmentation chain transfer (RAFT) polymerization, and nitroxide mediated polymerization (NMP). This chapter will be highlighting the state-of-the-art techniques for the synthesis of variety of MSNs, its functionalization using CRP techniques, and application of polymer functionalized MSNs.

Glucosamine Modified the Surface of pH-Responsive Poly(2-(diethylamino)ethyl Methacrylate) Brushes Grafted on Hollow Mesoporous Silica Nanoparticles as Smart Nanocarrier

“…Interestingly, some of these polymer brushes are stimuli-responsive; environmental changes such as light, temperature, and pH can alter the polymer chain conformation [ 22 , 23 , 24 ]. Various techniques have been used to grow polymer brushes on nanoparticle surfaces, including reversible addition–fragmentation chain transfer polymerization (RAFT) and atom transfer radical polymerization (ATRP) [ 25 , 26 , 27 ].…”

How Key Alterations of Mesoporous Silica Nanoparticles Affect Anti-Lung Cancer Therapy? A Comprehensive Review of the Literature

“…While grafting-from entails altering the surface of MSNs with an initiator, followed by surface-initiated polymerization, grafting-to uses covalent bonding by reacting pre-synthesized macromolecules containing specified groups with specific groups affixed on the inorganic surface. Controlled radical polymerization techniques, such as RAFT, ATRP, or NMP ( Figure 4 ), 64 can be used to build polymer chains.

Figure 4 Schematic illustration for the production of MSNs grafted with a copolymer of positively charged quaternary amines and PEG using RAF and addition-fragmentation equilibria during RAFT polymerization.

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“…While grafting-from entails altering the surface of MSNs with an initiator, followed by surfaceinitiated polymerization, grafting-to uses covalent bonding by reacting pre-synthesized macromolecules containing specified groups with specific groups affixed on the inorganic surface. Controlled radical polymerization techniques, such as RAFT, ATRP, or NMP (Figure 4), 64 can be used to build polymer chains.…”

Polymer grafting on nitrone functionalized green silica via “grafting from” and “grafting to” approaches through enhanced spin capturing polymerization and a 1,3-dipolar cycloaddition reaction

“…16 The grafting of suitable silanes over silica surfaces capable of polymerization can be carried out via cocondensation or post-modification. The co-condensation method [17][18][19][20][21][22] is a one-step method of synthesis of functionalized silica from its precursor, whereas the postmodification [23][24][25][26][27][28][29] method is a two-step process that includes the synthesis of silica followed by functionalization.…”