UCLA

Synthetic hydrophilic polymers are a type of polymers with polar or charged functional groups, and such functional groups render them with favorable interactions with water, leading to solubility or swellability. These polymers have been used in a wide variety of applications because they can be fabricated into novel materials with customized properties through carefully designed synthetic strategy and proper modification.

In the first chapter, a series of polyacrylamide (PAM) based polymers were applied to cohesionless, sandy soil for dust suppression. PAM is a hydrogel, a hydrophilic crosslinked polymer that does not dissolve in water and is a super water absorbent. We copolymerized PAM with hydrophobic units to control the polymer swelling ratio, and thus managed to mitigate the undesirable polymer swelling, soil matrix expansion, and the mechanical strength loss upon wet-dry processes. We further demonstrated that the treatment depth is controllable, which is crucial to minimize environmental impact, by fine-tuning the precursor composition for in-situ curing.

In the second and third chapters, we combined the functions of piezoresistive strain sensing and photothermal actuation into a single material, resembling living organisms’ neuromuscular behaviors. This design solved the limitation of conventional physically-integrated sensory actuator systems with interface constraints and predefined functions. The material composed of an interpenetrating double-network of a nanostructured thermo-responsive hydrogel poly(N-isopropylacrylamide) and a light-absorbing, electrically conductive polymer. When connected to a control circuit, these muscle-like materials achieved closed-loop feedback controlled, reversible step motion.

In the fourth chapter, polydopamine (PDA) nanoparticles mixed with large pore MSNs were used to deliver drugs. This research seeks to develop nanotherapeutics to deliver an ultra-short course tuberculosis treatment regimen via inhalation, for both drug-sensitive and drug-resistant tuberculosis (TB). We shall develop in an iterative process nanotherapeutics that safely and effectively deliver each of the four drugs alone and in combination as well as nanotherapeutics that can deliver multiple drugs. We evaluated the optimized nanotherapeutics for safety and efficacy in treating tuberculosis in a murine model of pulmonary TB when administered via inhalation, both alone and in combination with oral therapy with the same drugs.