Chemical vapor deposition (CVD) polymerization utilizes the delivery of vapor-phase monomers to form chemically well-defined polymeric films directly on the surface of a substrate. CVD polymers are desirable as conformal surface modification layers exhibiting strong retention of organic functional groups, and, in some cases, are responsive to external stimuli. Traditional wet-chemical chain- and step-growth mechanisms guide the development of new heterogeneous CVD polymerization techniques. Commonality with inorganic CVD methods facilitates the fabrication of hybrid devices. CVD polymers bridge microfabrication technology with chemical, biological, and nanoparticle systems and assembly. Robust interfaces can be achieved through covalent grafting enabling high-resolution (60 nm) patterning, even on flexible substrates. Utilizing only low-energy input to drive selective chemistry, modest vacuum, and room-temperature substrates, CVD polymerization is compatible with thermally sensitive substrates, such as paper, textiles, and plastics. CVD methods are particularly valuable for insoluble and infusible films, including fluoropolymers, electrically conductive polymers, and controllably crosslinked networks and for the potential to reduce environmental, health, and safety impacts associated with solvents. Quantitative models aid the development of large-area and roll-to-roll CVD polymer reactors. Relevant background, fundamental principles, and selected applications are reviewed.

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ethyl methacrylate-co-ethylene glycol dimethacry late] (PDE) thin films were synthesized via initiated chemical vapor deposition (iCVD) and reacted with 1,3-propane sultone to obtain the zwitterionic structure. The cross-linker ethylene glycol dimethacrylate (EGDMA) was utilized to make the copolymer insoluble in water. The composition of the copolymer was tuned by varying the flow rates of precursors and calculated from Fourier transform infrared spectroscopy (FTIR) spectra. The zwitterionic coatings were covalently grafted on to reverse osmosis (RO) membranes, and surface characterizations were carried out. Scanning electron microscope (SEM) and atomic force microscope (AFM) revealed that the iCVD zwitterionic coatings were conformal and smooth over the RO membrane, and the coating thickness can be measured by using ellipsometry. Salt rejection was not impaired by the coating. Permeation tests were carried out under different feed pressures, film thicknesses, and film compositions, showing a 15% to 43% reduction in permeation. Cell adhesion tests were carried out using Escherichia coli, and the coated RO membranes showed superior antifouling performance compared with the bare RO membrane. This is the first time that the library of iCVD functional groups has been extended to charged zwitterionic moieties, and the zwitterionic coatings have been applied on delicate substrates, such as RO membranes.

Successfully commercialized poly(ethylene oxide) (PEO)based solid polymer batteries (SPBs) are expected to continuously play a key role in the next generation of high-energy density lithium-ion battery technologies. However, the introduction of high-voltage cathodes, accompanied by safety concerns such as PEO decomposition and the associated gas release, is worthy of more attention. This study employs in situ DEMS to study the gassing behavior of LiCoO 2 |PEO-LiTFSI|Li SPBs. The experiments, together with theory calculations, reveal that a surface catalytic effect of LiCoO 2 is the root cause of the unexpected H 2 gas release of PEO-based SPBs at 4.2 V. The surface coating of LiCoO 2 with a stable solid electrolyte Li 1.4 Al 0.4 Ti 1.6 (PO 4 ) 3 (LATP) can mitigate such a surface catalytic effect and therefore extend the stable working voltage to >4.5 V. The crossover effect of HTFSI, which is generated at the cathode side due to oxidation/dehydration of PEO and reacts with lithium at the anode side, is proposed to explain the H 2 generation behavior.

We describe a potentially universal, simple and cheap method to prepare water-compatible molecularly imprinted polymer nanoparticles (MIP-NPs) as synthetic antibodies against proteins. The strategy is based on a solid phase synthesis approach where glass beads (GBs) are functionalized with a metal chelate, acting as a general affinity ligand to attract surface-bound histidines present on proteins. This configuration enables an oriented immobilization of the proteins, upon which thermoresponsive MIP-NPs are synthesized. The GBs play the role of both a reactor and a separation column since, after synthesis, the MIP-NPs are released from the support by a simple temperature change, resulting in protein-free polymers. The resulting MIP-NPs are endowed with improved binding site homogeneity, since the binding sites have the same orientation. Moreover, they are stable (no aggregation) in a buffer solution for prolonged storage time and exhibit apparent dissociation constants in the nanomolar range, with little or no cross-reactivity toward other proteins.

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Poly(4-aminostyrene) (PAS) thin films were synthesized via initiated chemical vapor deposition (iCVD) with tert-butyl peroxide as the initiator, representing the first time that a library of iCVD functional groups has been extended to amine moieties. The retention of the pendent amine chemical functionality was confirmed by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). Scanning electron microscope (SEM) reveals that the iCVD PAS coatings are conformal over nonplanar structures. Fluorescence microscopy and photoluminescence of quantum dot functionalized surfaces confirm that the reactive amine functional group density at the surface of iCVD PAS is ∼1 order of magnitude greater than for films grown by plasma-enhanced chemical vapor deposition (PECVD). The higher amine density of the iCVD films enables the formation of a robust nanoadhesive with complementary epoxy functional groups. Prototype microfluidic structures were fabricated using the low-temperature (50 °C) and zero-outgassing reaction between the amine groups in iCVD PAS and the epoxy groups in iCVD poly(glycidyl methacrylate) (PGMA). Bonded devices able to withstand >150 psi were achieved by combining polydimethylsiloxane (PDMS) and a variety of other materials including Si wafers, polycarbonate (PC), glass, polyethylene terephthalate (PET), polyethylene (PE), polyacrylate (PA), and cyclic olefin copolymer (COC). Additionally, the all-iCVD nanoadhesive bonding process displays high resistance against hydrolytic degradation (>2 weeks). Within the channels of the bonded devices, the epoxy and amine groups remain available for subsequent functionalization.

Billions of dollars are invested into the monoclonal antibody market every year to meet the increasing demand in clinical diagnosis and therapy. However, natural antibodies still suffer from poor stability and high cost, as well as ethical issues in animal experiments. Thus, developing antibody substitutes or mimics is a long‐term goal for scientists. The molecular imprinting technique presents one of the most promising strategies for antibody mimicking. The molecularly imprinted polymers (MIPs) are also called “molecularly imprinted synthetic antibodies” (MISAs). The breakthroughs of key technologies and innovations in chemistry and material science in the last decades have led to the rapid development of MISAs, and their molecular affinity has become comparable to that of natural antibodies. Currently, MISAs are undergoing a revolutionary transformation of their applications, from initial adsorption and separation to the rising fields of biomedicine. Herein, the fundamental chemical design of MISAs is examined, and then current progress in biomedical applications is the focus. Meanwhile, the potential of MISAs as qualified substitutes or even to transcend the performance of natural antibodies is discussed from the perspective of frontier needs in biomedicines, to facilitate the rapid development of synthetic artificial antibodies.