Layer-by-layer (LbL) assembly based on ionic interactions has proven to be a versatile route for surface modification and construction of ultrathin nanocomposites. Covalent LbL assembly based on facile ‘click’ covalent bond formation is an effective alternative, especially for the applications where a more robust ultrathin films or nanocomposites is desired. The subject of this dissertation focuses on the design of three different covalent LbL assemblies and their applications on conductive thin films, superhydrophobic surfaces, and solute responsive surfaces, respectively. Surface modification of PE substrates using covalent LbL assembly with PEI and Gantrez is a successful route to prepare a surface graft. The procedure is relative easy, fast and reproducible. Grafting multiple layers of PEI/Gantrez to the PE powder surface provided excellent coverage and promoted stable LbL film growth and excellent adhesion. This carbon black (CB) coated powder was compression molded into films, and their conductivity was measured, which revealed a percolation threshold below 0.01 wt % CB for the PEI-grafted system. Electrical conductivity of 0.2 S/cm was achieved with only 6 wt % CB, which is exceptional for a CB-filled PE film. Direct amination of MWNTs with PEI is a convenient and simple method leading to highly functionalized product that contains 6-8 % by weight PEI. Superhydrophobic PE films can be formed either from ionic LbL self-assembly of MWNT-NH-PEIs and poly(acrylic acid) or from covalent LbL self-assembly of MWNTNH- PEIs and Gantrez when the final graft is acrylated with octadecanoic acid. While the ionically assembled nanocomposite graft is labile under acid, the covalently assembled graft is more chemically robust. Responsive surfaces with significant, reversible, reproducible wettability changes can be prepared by covalent LbL grafting using PNIPAM-c-PNASI and aminated silica nanoparticles. A 65º ΔΘ value was observed with water vs. 1.4 M Na2SO4. The prepared film shows a high surface roughness of ~300 nm, which contributes to the large solute responsive ΔΘ values. The surfaces are reconfigurable in different solute conditions and that the changes in water contact angle are likely due to combination of change in surface roughness along with swell and intercalation of the solute ions into the PNIPAM surface.

Tailored fluoropolymers remain the leading choice for a wide variety of advanced high-performance applications, including electronic/optical and energy conversion, owing to their unique blend of complementary high-performance properties. Amorphous semi-fluorinated polymers exhibit improved solubility and melt processability when compared to traditional perfluoropolymers. A leading class of semi-fluorinated aryl ether polymers includes perfluorocyclobutyl (PFCB), perfluorocycloalkenyl (PFCA), and fluoroarylene vinylene ether (FAVE) polymers. Monomers containing aromatic trifluorovinyl ethers (TFVE) are used to synthesize PFCB polymers via radical-mediated [2+2] cyclodimerization. On the other hand, FAVE and PFCA polymers are polymerized via base-mediated nucleophilic addition/elimination of bisphenols with TFVE monomers and decafluorocyclohexene respectively. The use of different monomer cores (aromatic, aliphatic, contorted, and renewable) should help to develop general structure/property relationships for this versatile and expanding approach to semi-fluorinated aryl ether polymers. The enchainment of polycyclic aromatic hydrocarbon (PAH) cores with functional fluorocarbon groups (or segments) recently afforded a new class of semi- fluorinated polymers in the continuing quest for novel organic materials for potential applications in optoelectronic, gas-separation, and advanced composites. Chapter 2 details the incorporation of commercially available acenaphthenequinone was achieved to afford PFCB aryl ether polymers with excellent solubility, high thermal stability, and film-forming capability. Chapter 3 represents base-promoted nucleophilic addition/elimination of commercial bisphenols with TFVE-triphenylene monomers affording FAVE aryl ether polymers possessing excellent solution processability, high thermal stability and photostability. In addition, triphenylene-enchained FAVE polymers exhibit extreme thermal-oxidative photostability and emit blue light after heating in air at 250 °C for 24 h. Further, time-dependent density functional theory (TD-DFT) computations were performed to understand electronic polymer structures. In one case, post-polymerization Scholl coupling converted the central triphenylene core to afford a hexabenzocoronene containing semi-fluorinated polymer with new optoelectronic properties. Chapter 4 demonstrates synthesis and characterization of renewable semi-fluorinated polymers obtained using aliphatic diol isosorbide. This renewable diol readily polymerizes with bis-TFVE derivatives of bisphenol A and 6F to provide high molecular weight thermoplastics exhibiting excellent solubility and tough, transparent film-forming capability. Finally, Chapter 5 presents synthesis of TFVE enchained corannulene which gave blue-light emission and outstanding processability. Synthesis and characterization, including the new materials' optical, thermal, and electronic properties, is presented.