Integration of healability and mechanical robustness is challenging in the fabrication of highly transparent films for applications as protectors in optical and displaying devices. Here we report the fabrication of healable, highly transparent and scratch-resistant polymeric composite films that can conveniently and repeatedly heal severe damage such as cuts of several tens of micrometers wide and deep. The film fabrication process involves layer-by-layer (LbL) assembly of a poly(acrylic acid) (PAA) blend and branched poly(ethylenimine) (bPEI) blend, where each blend contains the same polyelectrolytes of low and high molecular weights, followed by annealing the resulting PAA/bPEI films with aqueous salt solution and incorporation of CaCO3 nanoparticles as nanofillers. The rearrangement of low-molecular-weight PAA and bPEI under aqueous salt annealing plays a critical role in eliminating film defects to produce optically highly transparent polyelectrolyte films. The in situ formation of tiny and well-dispersed CaCO3 nanoparticles gives the resulting composite films enhanced scratch-resistance and also retains the healing ability of the PAA/bPEI matrix films. The reversibility of noncovalent interactions among the PAA, bPEI, and CaCO3 nanoparticles and the facilitated migration of PAA and bPEI triggered by water enable healing of the structural damage and restoration of optical transparency of the PAA/bPEI films reinforced with CaCO3 nanoparticles.

Pore size uniformity is one of the most critical parameters in determining membrane separation performance. Recently, a novel type of conjugated microporous polymers (CMPs) has shown uniform pore size and high porosity. However, their brittle nature has prevented them from preparing robust membranes. Inspired by the skin-core architecture of spider silk that offers both high strength and high ductility, herein we report an electropolymerization process to prepare a CMP membrane from a rigid carbazole monomer, 2,2’,7,7’-tetra(carbazol-9-yl)-9,9’-spirobifluorene, inside a robust carbon nanotube scaffold. The obtained membranes showed superior mechanical strength and ductility, high surface area, and uniform pore size of approximately 1 nm. The superfast solvent transport and excellent molecular sieving well surpass the performance of most reported polymer membranes. Our method makes it possible to use rigid CMPs membranes in pressure-driven membrane processes, providing potential applications for this important category of polymer materials.

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Excipient enhanced growth (EEG) of inhaled submicrometer pharmaceutical aerosols is a recently proposed method intended to significantly reduce extrathoracic deposition and improve lung delivery. The objective of this study was to evaluate the size increase of combination drug and hygroscopic excipient particles in a characteristic model of the airways during inhalation using both in vitro experiments and CFD simulations. The airway model included a characteristic mouth-throat (MT) and upper tracheobronchial (TB) region through the third bifurcation (B3) and was enclosed in a chamber geometry used to simulate the thermodynamic conditions of the lungs. Both in vitro results and CFD simulations were in close agreement and indicated that EEG delivery of combination submicrometer particles could nearly eliminate MT deposition for inhaled pharmaceutical aerosols. Compared with current inhalers, the proposed delivery approach represents a 1–2 order of magnitude reduction in MT deposition. Transient inhalation was found to influence the final size of the aerosol based on changes in residence times and relative humidity values. Aerosol sizes following EEG when exiting the chamber (2.75–4.61 μm) for all cases of initial submicrometer combination particles were equivalent to or larger than many conventional pharmaceutical aerosols that frequently have MMADs in the range of 2–3 μm.

In this work, surface‐active polymer nanoparticles as well as polymer–polymer and polymer–metal nanoassembly particles are synthesized, and different parameters such as their size, morphologies, and assembling strength are studied. Nanoassembly particles are attractive because of the coupled properties with a large surface to volume ratio. A key challenge is to produce the core–shell polymer nanoparticles via single‐step processes. To address this concern, here, microfluidics approach and precise interfacial reaction strategies are used, and hence different types of surface layered polymer nanoparticles are obtained in one‐step processes. An inner core material is hydrophobic, whereas a hydrophilic surface layer (in situ formed during the polymerization process) swells in the aqueous environment. Moreover, three different reaction setups (batch, flow, and in situ) are applied in order to architect the nanoassembling hierarchical structures via layer‐by‐layer strategy. On the other side, polymer–metal nanoassembly particles as well as metal catalyzed metal deposited four layered nanoassembly particles of tuned size and compositions are produced. It is shown that these particles can be used as nanosensor particles for surface‐enhanced Raman spectroscopy.