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This study presents dual-responsive colloidal microgels to repair nonwoven fiber mats (NWFs) and recover their native morphological and functional properties. The formulation comprises poly(N-isopropylacrylamide-co-acrylic acid) (PNIPAmco-AA) microgels loaded with iron oxide nanoparticles acting as magneto-responsive "bricks" and poly(N-isopropylacrylamide-co-N-4-benzoylphenyl acrylamide) (PNIPAm-co-BPAm) serving as photo-cross-linkable "mortar". The formulation is employed to repair small tears in meltblown polypropylene (PP) and polybutylene terephthalate (PBT) NWFs and recover the functional properties of the native membranes. Specifically, magnetically directed and UV-light-triggered repair recovers (i) the topological integrity, as shown by optical microscopy and image analysis of PP and PBT NWFs, (ii) the mechanical properties, as demonstrated by the values of tensile modulus of native, damaged, and repaired PP NWFs, and (iii) the permeability to sodium chloride of both PP and PBT NWFs. A comparative study of repair using magneto-responsive and photo-cross-linkable vs photocross-linkable-only formulations demonstrate that magnetic localization is vital to ensure rapid, spatially accurate, and effective recovery of the morphological and functional properties of damaged NWFs.

This article presents an integrated experimental and computational study of DendriPeps, a novel class of dendrimers featuring a polyamidoamine (PAMAM) backbone hybridized with peptide segments. Hydroxyl‐terminated Generation 2 (G.2) DendriPeps, comprising either four lysines (Lys) or four glutamic acids (Glu), and G.3 DendriPeps, comprising 8 Lys or 8 Glu, were first characterized in terms of hydrodynamic radius (Rh) and ζ‐potential in aqueous solution. Unlike PAMAM dendrimers, DendriPeps form aggregates with Rh between 60 and 980 nm and ζ‐potential between −130 and 80 mV despite their strong net charge. Upon application of shear, all aggregates disassemble into monomeric DendriPeps (Rh ~ 1–3 nm), but reform rapidly as shear is removed. Rheological characterization confirmed that DendriPep aggregates are disrupted by mild shear, but reform reversibly. Molecular dynamics simulations, informed by titrimetry, suggest that DendriPep aggregation derives from their multipolar structure and ability to rearrange the intermolecular/intramolecular pairing of titratable moieties at different pH values.