Surface Chemistry & Engineering: Chemical Vapor Deposition
Back in 1966, William Gorham first described a reaction pathway using [2.2]Paracyclophane (PCP) as precursor molecule to form Poly(p-xylylene) (PPX) films and their functional forms at Union Carbide. In the following 60 years, the reaction scheme to form PPX films was adopted by chemical vapor deposition (CVD), a technique that provides a substrate-independent surface functionalization where the reactive species from the chemical precursors are radicalized in the vapor phase and allowed to deposit/spontaneously polymerize into conformally homogeneous polymer surfaces. CVD polymerization does not require any solvents or initiators, and the absence of side products and effective quantitative conversion make it a sustainable and popular process for surface functionalization particularly suited for engineering electronic- and bio-interfaces. CVD polymerization allows sequential deposition of different precursor components, as well as random copolymers, with the ability to produce gradients and microstructures, and post-CVD surface engineering via orthogonal transformation without altering the polymer skeletal composition.
CVD polymerization has become a widely popularized technology that, due to the high purity, flexibility, mechanical strength, and chemical inertness of CVD polymers, offers tremendous potential in various research fields ranging from microelectronics to photovoltaics, sensors, microelectrochemical materials, and drug-delivery systems. Additionally, CVD of various polymers have demonstrated its technological utility as a mode of depositing antimicrobial coatings for industrial products such as clinically used biomaterials and biomedical devices.
In Lahann Lab, we explore the utility of CVD for surface engineering of 3D nanostructures for various applications, and conduct fundamental studies to discern the deposition mechanism at the interface of synthetic chemistry and material science & engineering.
Current projects:
Mechanistic study of area-selective chemical vapor deposition (Xiaoyang Zhong)
Investigation of the growth mechanism and chiroptical properties of nanofibers prepared by LC-templated CVP (John Kim)
Chemical vapor polymerization of nanofiber array using ultra-thin LC film (Arit Patra)
Schematic of CVD polymerization process
Custom CVD system of Lahann Lab
Research Highlight
Changes in the optical appearances in liquid crystals under different electric voltage
