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With the growing number of applications for thin polymer films (e.g., corrosion-resistant coatings, photovoltaics, and optoelectronics), there is an urgent need to develop or advance cost-effective, versatile, and high-throughput manufacturing processes to produce thin polymer films and coatings with controllable properties (e.g., morphology, composition). In this work, we present a simple, cost-effective, and scalable approach: the air-assisted electrospray method for thin film coating. We systematically investigate its capabilities for producing coatings with a wide range of surface morphologies, its compatibility with three-dimensional substrates, and the fundamental understanding of the process. Through systematic control of concentration, needle configuration, and polymer selection, we demonstrate the ability to produce coating morphologies with diverse structural characteristics and excellent reproducibility. Notably, the introduction of air assistance through a coaxial needle greatly enlarges the range of achievable morphologies, particularly at lower concentrations. We also found that the position of the airflow relative to the solution is critical for determining the polymer film properties. Furthermore, we demonstrate its broad application potential in the fabrication of binderless electrodes for sodium-ion batteries. 

Polypeptoids bearing carboxylic acid groups on the N -substituent are useful building blocks for the construction of peptidomimetic supramolecular assemblies with stimuli-responsive properties. Towards this end, N -(3- tert -butoxy-3-oxopropyl) glycine derived N -carboxyanhydride ( t BuO 2 Pr-NCA) has been successfully synthesized and polymerized using primary amine initiators to produce the corresponding poly( N -(3- tert -butoxy-3-oxopropyl) glycine) with molecular weights ( M n ) of 5.6–59 kg mol −1 and a narrow molecular weight distribution (PDI = 1.003–1.026). The polymerization was shown to proceed in a controlled manner, evidenced by the good agreement of the experimental molecular weight ( M n ) with theoretical values and narrow molecular weight distribution in a wide range of monomer-to-initiator ratios ([M] 0  : [I] 0 = 25 : 1–200 : 1), the linear increase of M n with conversion and the second-order polymerization kinetics. The cloaked carboxyl groups on the poly( N -(3- tert -butoxy-3-oxopropyl) glycine) can be readily unveiled in mild acidic conditions to yield the poly( N -(2-carboxyethyl) glycine), a structural mimic of poly(glutamic acid). The poly( N -(2-carboxyethyl) glycine) polymer is a weak polyelectrolyte whose hydrodynamic size in water can be controlled by the solution pH.