Conformal single-layer encapsulation of PEDOT at low substrate temperature

Chen, Nan; Wang, Xiaoxue; Gleason, Karen K.

doi:10.1016/j.apsusc.2014.06.123

Cited by 6 publications

(3 citation statements)

References 37 publications

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“…Solid oxidants are commonly placed on a crucible in the reactor and are sublimated at a temperature between 170° C and 350 °C. Despite the wealth of the literature on oCVD PEDOT via FeCl3, the sublimation rate and stability over time have never been reported [9,[12][13][14][17][18][19][20][21][22][23][24]. These two parameters are important since the sublimation rate of the oxidant allows controlling the gas phase composition and, subsequently, the film's characteristics.…”

Section: Introductionmentioning

confidence: 99%

An out of the box vision over oxidative chemical vapor deposition of PEDOT involving sublimed iron trichloride

et al. 2020

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Oxidative chemical vapor deposition (oCVD) is an efficient technique to produce highly conductive films of Poly (3,4-ethylenedioxythiophene) (PEDOT). Despite numerous studies on the oCVD of PEDOT films, there is limited information on the stability of the sublimation of solid oxidants and on their impact on the polymerization reactions. In this work, we use an in situ Quartz Crystal Microbalance to monitor film formation over time. Through a series of deposition experiments between 20 °C and 100 °C and for FeCl3/EDOT molar gas ratios between 17.3 and 75.3, we analyze in detail the correlations between process parameters and film morphology, composition, surface topography and electrical conductivity on 10 cm silicon wafers. By using multiple substrates at different positions into the reactor, we demonstrate that the formation of PEDOT occurs uniformly through purely surface reactions, following step growth polymerization principles. These results pave the way towards highly conductive oCVD PEDOT films processed from convenient solid oxidants.

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Section: Introductionmentioning

confidence: 99%

An out of the box vision over oxidative chemical vapor deposition of PEDOT involving sublimed iron trichloride

et al. 2020

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“…The chemical composition of the resulting polymer, however, was not controllable. Maleic anhydride has been previously copolymerized with styrene, divinylbenzene, 4-aminostyrene, N , N -dimethylacrylamide, and di(ethylene glycol) di(vinyl ether) using iCVD, but its homopolymerization has been difficult due to the slow polymerization rate …”

Section: Introductionmentioning

confidence: 99%

“…29 The chemical composition of the resulting polymer, however, was not controllable. Maleic anhydride has been previously copolymerized with styrene, 30 divinylbenzene, 31 4-aminostyrene, 32 N,N-dimethylacrylamide, and di(ethylene glycol) di(vinyl ether) 33 using iCVD, but its homopolymerization has been difficult due to the slow polymerization rate. 34 We demonstrate stoichiometric synthesis of PMAH and a series of copolymers of poly(methacrylic anhydride-comethacrylic acid) (P(MAH-co-MAA)) via iCVD.…”

Section: Introductionmentioning

confidence: 99%

Designing pH-Responsive Biodegradable Polymer Coatings for Controlled Drug Release via Vapor-Based Route

Shi

Wang

et al. 2018

ACS Appl. Mater. Interfaces

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We present the design of a novel pH-responsive drug release system that is achieved by solventless encapsulation of drugs within a microporous membrane using a thin capping layer of biodegradable poly(methacrylic anhydride) (PMAH) coating. The coating was synthesized via a mild vapor polymerization process, namely, initiated chemical vapor deposition, which allowed perfect retention of the anhydride groups during deposition. The synthesized polyanhydride underwent degradation upon exposure to aqueous buffers, resulting in soluble poly(methacrylic acid). The degradation behavior of PMAH is highly pH-dependent, and the degradation rate under pH 10 is 15 times faster than that under pH 1. The release profile of a model drug rifampicin clearly exhibited two stages: the initial stage when the coatings were being degraded but the drugs were well stored and the second stage when drugs were gradually exposed to the medium and released. The drug release also showed strong pH responsiveness where the duration of the initial stage under pH 1 was more than 7 and 3 times longer than that under pH 10 and 7.4, respectively, and the release rates at pH 7.4 and 10 were significantly faster than that at pH 1. The pH-dependent degradation of the encapsulant thus enabled good preservation of drugs under low-pH environment but high drug release efficiency under neutral and alkaline environment, suggesting potential applications in site-specific drug delivery systems.

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Stabilizing the Wettability of Initiated Chemical Vapor Deposited (iCVD) Polydivinylbenzene Thin Films by Thermal Annealing

Zhao

Wang

Gleason

2017

Adv Materials Inter

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Maintaining stable surface properties, such as wetting, remains a challenge for many applications of functional coatings. Here, this paper reports a study on the stability of the surface properties of polydivinylbenzene (PDVB). The PDVB thin films are synthesized via initiated chemical vapor deposition (iCVD). The decrease of receding water contact angles and increase of contact angle hysteresis of iCVD PDVB over time are found to be related with surface oxidation during air exposure. Fourier transform infrared and X‐ray photoelectron spectroscopy reveal the generation carbonyl and epoxy groups and the consumption of pendant vinyl groups in the oxidation process. A modified first‐order kinetic model describes the dynamic process, and the apparent reaction rate constant for the oxidation of iCVD PDVB is 0.0238–0.0294 h−1. In order to inhibit the oxidation and stabilize the wettability of iCVD PDVB, an in situ thermal annealing process is developed. This thermal treatment is effective in improving the cross‐linking degree of iCVD PDVB, slowing down the rate of oxidation, and therefore significantly enhancing the long‐term wettability. The advancing and receding contact angles of annealed iCVD PDVB are stable even after exposure to air for two months. The reported thermal annealing approach also improves the mechanical properties of iCVD PDVB.

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Conformal single-layer encapsulation of PEDOT at low substrate temperature

Cited by 6 publications

References 37 publications

An out of the box vision over oxidative chemical vapor deposition of PEDOT involving sublimed iron trichloride

An out of the box vision over oxidative chemical vapor deposition of PEDOT involving sublimed iron trichloride

Designing pH-Responsive Biodegradable Polymer Coatings for Controlled Drug Release via Vapor-Based Route

Stabilizing the Wettability of Initiated Chemical Vapor Deposited (iCVD) Polydivinylbenzene Thin Films by Thermal Annealing

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