## 3 Polymerization Reactions within AAO Templates
### Radical Polymerization
Although the authors observed that the obtained conversion was lower compared to that of the macroscale, the reaction also proceeded up to high conversion, between 77 and 83%, depending on the selected pore diameter. They also observed a pseudo first-order kinetic dependence for the lowest pore diameters studied, thus indicating an increased level of control over the reaction and the elimination of termination and side reactions with decreasing pore diameter. The molecular weight of the polymers, Mn, obtained in AAO templates increased linearly with monomer conversion, between 30,000 g/mol and 111,000 g/mol, and D, varied from 1.1 to 1.7. Therefore, the reaction in nanoconfinement led to a rather homogeneous structure of chains while, for bulk polymerization, the authors suggested probable chain transfer to monomer/polymer reactions, thus indicating the polymer heterogeneity and no control over the reaction for the polymerization in bulk. The authors claimed that AAO membranes are an excellent tool to increase control over the polymerization of vinyl pyrrolone and to produce materials of well-defined properties. Polymerization of ionic monomers. Recently, the free radical polymerization of a series of ionic monomers in AAO templates was studied by [PERSON] et al. [29; 127; 128]. First, 1-butyl-3-vinylimidazolium bis-(trifluoromethylmethanesulfonyl) amide ([bvim][NTf2]) was selected as ionic monomer and AIBN as initiator. The progress of the reactions was monitored by DSC and compared to Broadband Dielectric Spectroscopy results. From isothermal DSC measurements at 363 K, the authors detected a pronounced shift of the  
Figure 7: (**a**) Heat flow measured in the nanoconfined polymerization of MMA in AAO 60 at different temperatures under isothermal conditions. (**b**) Evolution of conversion with time. (**c**) Kinetic plot of MMA polymerization conducted in AAO templates with nanopore of 60 nm diameter at 60, 70, 80 and 90 \({}^{\circ}\)C. The bold lines indicate the fit of the kinetics to the mathematical model described herein [126]. Copyright 2017. Reproduced with permission from the publisher: ACS. exothermic peak to shorter times depending on the polymerization process. These results emphasized the acceleration of the reaction as the pore size decreased, as shown in Figure 8. However, for the smallest pore sizes, some saturation effect was visible. The authors also found that the conversion was around 95% for all examined samples, much higher than typical monomer conversion of radical polymerization (usually, in the range of 40\(-\)85%), thus indicating a strong influence of the AAO templates on the reactivity of monomeric ionic liquid. Moreover, the molecular weight of the macromolecules synthesized under confinement was higher with respect to polymers synthesized in bulk. Interestingly, they found that the examined nanopolymerization was quite heterogeneous. Consequently, the properties (molecular dynamics and glass transition temperatures) of the materials recovered at the pore walls and in the middle of the pores differed significantly. In a later work, the same authors [128] studied the influence of small modifications in the chemical structure of the ionic monomer on the properties of synthesized polymers when they substituted the butyl group for an ethyl group and found a dramatic change in the polymer properties. Very recently, the same group studied the influence of a sterically hindered ionic monomer when the polymerization was carried out by free radical polymerization in two kinds of hard confinement systems, AAO nanoporous membranes and high pressure compressed systems, that influence the free volume of polymerization in different ways. The idea was that the two systems would act as additional driving forces to polymerize sterically hindered monomers in relatively short times.