The authors gratefully acknowledge financial support from the US Air Force Office of Scientific Research, under agreement number FA9550-14-1-0128. T. L. A. also gratefully acknowledges partial support by the David and Lucille Packard Foundation.

Read MSDS for reagents and follow all chemical safety measures as required by your institution.
1. Deposition of Cl-PProDOT and Cl-PTT
<ol>
	<li>Build the structure of the custom-built tubular vapor deposition chamber as shown in Figure 1.
	<ol>
		<li>Make a 1/4-in. (outer diameter, O.D.) fused quartz side inlet to a 2-in. (O.D.) fused quartz tube. Make a cold trap with a custom-built U-shape 1-in. stainless-steel tube and a Dewar flask.</li>
		<li>Connect the quartz tube with a vacuum gauge and cold trap using stainless-steel KF connectors and quick-connect couplings. Place the monomer in a quartz ampule and connect the ampule to the tubular chamber via 1/4-in. quick-connect couplings and a needle valve. Place the oxidant in a crucible in the chamber.</li>
		<li>Use separate heating tapes as heating sources for the oxidant, substrates and the monomer. Add a gas inlet at the right end of the chamber to introduce additional noble gases to control the process pressure if necessary.</li>
	</ol>
	</li>
	<li>Deposition of Cl-PProDOT
	<ol>
		<li>Add 50 mg of 3,4-propylenedioxythiophene (ProDOT) in the monomer ampoule and connect it to the tubular chamber. Keep the needle valve open.</li>
		<li>Put substrates (glass slide, fabrics, paper, etc.) in the chamber. The size of the substrates is 1.3 cm x 2.5 cm.</li>
		<li>Add 50 mg of FeCl3 in a 5-mL crucible and place it in the chamber. 
		NOTE: The relative positions of the monomer inlet, substrates and the crucible are shown in Figure 1. The distance between the monomer inlet and the crucible is 13 cm.</li>
		<li>Turn on the pump. Close the valve on the right end of the chamber slowly. After the chamber pressure is below 525 mTorr (70 Pa), add liquid nitrogen in the cold trap.</li>
		<li>Wrap the three heating zones with heating tape and connect the heating tape to the temperature controllers.</li>
		<li>When the pressure decreases to the processing pressure (52.5 mTorr, 7 Pa), close the needle valve of the monomer container.</li>
		<li>Start heating the oxidant, the substrates and the monomer at 170 &#176;C, 80 &#176;C, and 80 &#176;C, respectively. After ~10 min, FeCl3 is vaporized and the red FeCl3 solid is formed in the cool region.</li>
		<li>Open the needle valve of the monomer container. 
		NOTE: Blue-colored thin films will be formed in the substrate region. Typical growth rates are ~10 nm/min. Ensure that the FeCl3 vapor is formed in the chamber before opening the needle valve of the monomer container. Otherwise, the monomer will react with FeCl3 solid in the crucible and form a polymer layer which prevents the further vaporization of the oxidant.</li>
		<li>Close the needle valve of the monomer container when the desired thickness is achieved. Turn off all heating tape and cool the system to room temperature.</li>
		<li>Open the gas inlet valve and turn off the pump.</li>
		<li>Take the samples out of the chamber. Carefully immerse the samples in methanol for 30 min to remove the residual oxidant and monomer. 
		NOTE: Rinsing time should increase as film thickness increases. 30-min rinsing is typical for films thinner than 100 nm on glass slides. Films thicker than 500 nm might delaminate from the substrate when rinsing.</li>
		<li>Carefully blow dry the samples with nitrogen gas.</li>
	</ol>
	</li>
	<li>Deposition of Cl-PTT
	<ol>
		<li>Add 50 mg of thieno[3,2-b]thiophene (TT) in the monomer ampoule and connect it to the tubular chamber. Keep the needle valve open.</li>
		<li>Repeat steps 1.2.2. to 1.2.12.</li>
	</ol>
	</li>
</ol>
2. Deposition of Br-PEDOT
<ol>
	<li>Deposition Chamber Setup
	<ol>
		<li>Add an additional 1/4-in. side inlet for oxidants to the quartz tube and make it 8 in. apart from the monomer inlet. Place the liquid oxidant in a quartz ampule and connect the ampule to the tubular chamber the same way as the monomer (Figure 2).</li>
	</ol>
	</li>
	<li>Deposition of Br-PEDOT
	<ol>
		<li>Add 2 mL of 3,4-ethylenedioxythiophene (EDOT) in the monomer ampule and connect the ampule to the tubular chamber. Keep the needle valve open.</li>
		<li>Place substrates (glass slide, fabrics, paper, etc.) in the tubular chamber near the monomer vapor inlet. The size of the substrate is 1.3 cm x 2.5 cm.</li>
		<li>In a fume hood, add 2 mL of Br2 in the oxidant ampule, connect the ampule to the needle valve and keep the needle valve closed. Connect the needle valve to the quartz tube. 
		Caution: Br2 is a hazardous material. Use caution when handling.</li>
		<li>Turn on the pump. Close the valve on the right end of the chamber slowly. After the chamber pressure is below 525 mTorr (70 Pa), add liquid nitrogen in the cold trap.</li>
		<li>Wrap the monomer region with heating tape and connect it with a temperature controller. Maintain the substrate and oxidant region at room temperature.</li>
		<li>When the pressure decreases to the processing pressure of 52.5 mTorr (7 Pa), open the needle valve of the oxidant. 
		NOTE: The reaction is very fast. Blue PEDOT films will form close to the monomer inlet because Br2 is very volatile.</li>
		<li>Close the needle valves of both the monomer and the oxidant when desired thickness is achieved.</li>
		<li>Turn off the heating tape and cool the system to room temperature.</li>
		<li>Open the gas inlet valve and turn off the pump. Take the samples out of the chamber. 
		NOTE: Rinsing is not needed for Br2-doped polymers.</li>
	</ol>
	</li>
</ol>

<ol>
	<li>Kaltenbrunner, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrathin+and+lightweight+organic+solar+cells+with+high+flexibility.">Ultrathin and lightweight organic solar cells with high flexibility.</a> Nat. Commun. 3, 770 (2012).</li><li>Savagatrup, S., Printz, A. D., O'Connor, T. F., Zaretski, A. V., Lipomi, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecularly+Stretchable+Electronics.">Molecularly Stretchable Electronics.</a> Chem. Mater. 26, 3028-3041 (2014).</li><li>Lee, J. -. Y., Connor, S. T., Cui, Y., Peumans, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Semitransparent+Organic+Photovoltaic+Cells+with+Laminated+Top+Electrode.">Semitransparent Organic Photovoltaic Cells with Laminated Top Electrode.</a> Nano Lett. 10, 1276-1279 (2010).</li><li>Kaltenbrunner, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+ultra-lightweight+design+for+imperceptible+plastic+electronics.">An ultra-lightweight design for imperceptible plastic electronics.</a> Nature. 499, 458-463 (2013).</li><li>Jost, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Carbon+coated+textiles+for+flexible+energy+storage.">Carbon coated textiles for flexible energy storage.</a> Energy Environ. Sci. 4, 5060-5067 (2011).</li><li>Hu, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stretchable,+Porous,+and+Conductive+Energy+Textiles.">Stretchable, Porous, and Conductive Energy Textiles.</a> Nano Lett. 10, 708-714 (2010).</li><li>Jost, K., Dion, G., Gogotsi, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Textile+energy+storage+in+perspective.">Textile energy storage in perspective.</a> J. Mater. Chem. A. 2, 10776-10787 (2014).</li><li>Ding, Y., Invernale, M. A., Sotzing, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conductivity+Trends+of+PEDOT-PSS+Impregnated+Fabric+and+the+Effect+of+Conductivity+on+Electrochromic+Textile.">Conductivity Trends of PEDOT-PSS Impregnated Fabric and the Effect of Conductivity on Electrochromic Textile.</a> ACS Appl. Mater. Interfaces. 2, 1588-1593 (2010).</li><li>Hong, K. H., Oh, K. W., Kang, T. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+and+properties+of+electrically+conducting+textiles+by+in+situ+polymerization+of+poly(3,4-ethylenedioxythiophene).">Preparation and properties of electrically conducting textiles by in situ polymerization of poly(3,4-ethylenedioxythiophene).</a> J. Appl. Polym. Sci. 97, 1326-1332 (2005).</li><li>Xu, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fabric+electrodes+coated+with+polypyrrole+nanorods+for+flexible+supercapacitor+application+prepared+via+a+reactive+self-degraded+template.">Fabric electrodes coated with polypyrrole nanorods for flexible supercapacitor application prepared via a reactive self-degraded template.</a> Org. Electron. 26, 292-299 (2015).</li><li>Du, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thermoelectric+Fabrics:+Toward+Power+Generating+Clothing.">Thermoelectric Fabrics: Toward Power Generating Clothing.</a> Sci. Rep. 5, 6411 (2015).</li><li>Yatvin, J., Sherman, S. A., Filocamo, S. F., Locklin, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Direct+functionalization+of+Kevlar[registered+sign]+with+copolymers+containing+sulfonyl+nitrenes.">Direct functionalization of Kevlar[registered sign] with copolymers containing sulfonyl nitrenes.</a> Polym. Chem. 6, 3090-3097 (2015).</li><li>Musumeci, C., Hutchison, J. A., Samori, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Controlling+the+morphology+of+conductive+PEDOT+by+in+situ+electropolymerization:+from+thin+films+to+nanowires+with+variable+electrical+properties.">Controlling the morphology of conductive PEDOT by in situ electropolymerization: from thin films to nanowires with variable electrical properties.</a> Nanoscale. 5, 7756-7761 (2013).</li><li>Allison, L., Hoxie, S., Andrew, T. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Towards+seamlessly-integrated+textile+electronics:+methods+to+coat+fabrics+and+fibers+with+conducting+polymers+for+electronic+applications.">Towards seamlessly-integrated textile electronics: methods to coat fabrics and fibers with conducting polymers for electronic applications.</a> Chem. Commun. 53, 7182-7193 (2017).</li><li>Alf, M. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemical+Vapor+Deposition+of+Conformal,+Functional,+and+Responsive+Polymer+Films.">Chemical Vapor Deposition of Conformal, Functional, and Responsive Polymer Films.</a> Adv. Mater. 22, 1993-2027 (2010).</li><li>Goktas, H., Wang, X., Boscher, N. D., Torosian, S., Gleason, K. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functionalizable+and+electrically+conductive+thin+films+formed+by+oxidative+chemical+vapor+deposition+(oCVD)+from+mixtures+of+3-thiopheneethanol+(3TE)+and+ethylene+dioxythiophene+(EDOT).">Functionalizable and electrically conductive thin films formed by oxidative chemical vapor deposition (oCVD) from mixtures of 3-thiopheneethanol (3TE) and ethylene dioxythiophene (EDOT).</a> J. Mater. Chem. C. 4, 3403-3414 (2016).</li><li>Sadki, S., Schottland, P., Brodie, N., Sabouraud, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+mechanisms+of+pyrrole+electropolymerization.">The mechanisms of pyrrole electropolymerization.</a> Chem. Soc. Rev. 29, 283-293 (2000).</li><li>Bhattacharyya, D., Howden, R. M., Borrelli, D. C., Gleason, K. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vapor+phase+oxidative+synthesis+of+conjugated+polymers+and+applications.">Vapor phase oxidative synthesis of conjugated polymers and applications.</a> J. Polym. Sci., Part B: Polym. Phys. 50, 1329-1351 (2012).</li><li>Yamato, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+of+free-standing+poly(3,4-ethylenedioxythiophene)+conducting+polymer+films+on+a+pilot+scale.">Synthesis of free-standing poly(3,4-ethylenedioxythiophene) conducting polymer films on a pilot scale.</a> Synth. Met. 83, 125-130 (1996).</li><li>Cheng, N., Zhang, L., Joon Kim, J., Andrew, T. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vapor+phase+organic+chemistry+to+deposit+conjugated+polymer+films+on+arbitrary+substrates.">Vapor phase organic chemistry to deposit conjugated polymer films on arbitrary substrates.</a> J. Mater. Chem. C. 5, 5787-5796 (2017).</li><li>Borrelli, D. C., Lee, S., Gleason, K. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optoelectronic+properties+of+polythiophene+thin+films+and+organic+TFTs+fabricated+by+oxidative+chemical+vapor+deposition.">Optoelectronic properties of polythiophene thin films and organic TFTs fabricated by oxidative chemical vapor deposition.</a> J. Mater. Chem. C. 2, 7223-7231 (2014).</li><li>Jo, W. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oxidative+Chemical+Vapor+Deposition+of+Neutral+Hole+Transporting+Polymer+for+Enhanced+Solar+Cell+Efficiency+and+Lifetime.">Oxidative Chemical Vapor Deposition of Neutral Hole Transporting Polymer for Enhanced Solar Cell Efficiency and Lifetime.</a> Adv. Mater. 28, 6399-6404 (2016).</li><li>Wang, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CVD+Polymers+for+Devices+and+Device+Fabrication.">CVD Polymers for Devices and Device Fabrication.</a> Adv. Mater. 29, 1604606 (2017).</li><li>Kovacik, P., Hierro, G. d., Livernois, W., Gleason, K. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Scale-up+of+oCVD:+large-area+conductive+polymer+thin+films+for+next-generation+electronics.">Scale-up of oCVD: large-area conductive polymer thin films for next-generation electronics.</a> Mater. Horiz. 2, 221-227 (2015).</li><li>Barr, M. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Direct+Monolithic+Integration+of+Organic+Photovoltaic+Circuits+on+Unmodified+Paper.">Direct Monolithic Integration of Organic Photovoltaic Circuits on Unmodified Paper.</a> Adv. Mater. 23, 3500-3505 (2011).</li></ol>

The authors have nothing to disclose.

The mechanism of the reaction is oxidative polymerization. Polymer coating methods using the same mechanism include electropolymerization17 and vapor phase polymerization18. Electropolymerization requires a conductive substrate, lacks the advantage of uniform and conformal coating, and is an environmentally-unfriendly solution-based method19. The existing vapor phase polymerization method is similar to the method reported here but can only polymerize...

Polymeric conducting and semiconducting materials have unique properties, such as flexibility1, stretchability2, transparency3, and low density,4 which provide extraordinary opportunities for creating next-generation electronic devices on nontraditional substrates. Currently, many researchers are endeavoring to take advantage of the unique properties of polymeric materials to create flexible and/or wearable electronics5,6 and smart textiles7. However, the ability to conformally coat highly textured surfaces and non-robust substrates, such as paper, fabrics and threads/yarns, remains unmastered. Most commonly, polymers are synthesized and coated on surfaces using solution methods.8,9,10,11,12 Although solution methods provide polymer coated fibers/textiles, the coatings thus obtained are often non-uniform and easily damaged by small physical stresses13,14 . Solution methods are also not applicable to coating paper because of wetting problems.
Reactive vapor deposition can create conformal conjugated polymer films on a diverse range of substrates, irrespective of surface chemistry/composition, surface energy and surface roughness/topography15. In this approach, conjugated polymers are synthesized in the vapor phase by simultaneously delivering monomer and oxidant vapors to a surface. Polymerization and film formation occurs on the surface in a single, solvent-free step. This method is theoretically applicable to any conjugated polymer that can be synthesized by oxidative polymerization using solution methods. However, to date, protocols for depositing only a narrow set of conjugated polymer structures are known.15
Here, we demonstrate the deposition of conductive poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(3,4-propylenedioxythiophene) (PProDOT), and semiconducting poly(thieno[3,2-b]thiophene) (PTT) films via reactive vapor deposition. Two kinds of oxidants, solid FeCl3 and liquid Br2, are used in the process. The corresponding polymers are named Cl-PProDOT, Cl-PTT, and Br-PEDOT. Both conventional substrates, glass slides, and unconventional textured substrates, such as paper, towels and fabrics, were coated with the polymer films.
This protocol describes the setup of the custom-built vapor deposition chamber and the details of the deposition process. It is intended to help new practitioners to build their deposition system and avoid common pitfalls associated with vapor-phase synthesis.

<table><tbody><tr><td>3,4-Ethylenedioxythiophene, 97%</td><td>Sigma Aldrich</td><td>483028</td><td></td></tr><tr><td>3,4-Propylenedioxythiophene, 97%</td><td>Sigma Aldrich</td><td>660485</td><td></td></tr><tr><td>Thieno[3,2-b]thiophene, 95%</td><td>Sigma Aldrich</td><td>702668</td><td></td></tr><tr><td>FeCl&lt;sub&gt;3&lt;/sub&gt;, 97%</td><td>Sigma Aldrich</td><td>157740</td><td></td></tr><tr><td>Br&lt;sub&gt;2&lt;/sub&gt;</td><td>Sigma Aldrich</td><td>207888</td><td></td></tr></tbody></table>

reactive vapor deposition of conjugated polymer films on arbitrary substrates

We demonstrate a method of conformally coating conjugated polymers on arbitrary substrates using a custom-designed, low-pressure reaction chamber. Conductive polymers, poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(3,4-propylenedioxythiophene) (PProDOT), and a semiconducting polymer, poly(thieno[3,2-b]thiophene) (PTT), were deposited on unconventional highly-disordered and textured substrates with high surface areas, such as paper, towels and fabrics. This reported deposition chamber is an improvement of previous vapor reactors because our system can accommodate both volatile and nonvolatile monomers, such as 3,4-propylenedioxythiophene and thieno[3,2-b]thiophene. Utilization of both solid and liquid oxidants are also demonstrated. One limitation of this method is that it lacks sophisticated in situ thickness monitors. Polymer coatings made by the commonly used solution-based coating methods, such as spin-coating and surface grafting, are often not uniform or susceptible to mechanical degradation. This reported vapor phase deposition method overcomes those drawbacks and is a strong alternative to common solution-based coating methods. Notably, polymer films coated by the reported method are uniform and conformal on rough surfaces, even at a micrometer scale. This feature allows for future application of vapor deposited polymers in electronics devices on flexible and highly textured substrates.

The thickness of Cl-PProDOT films formed on 1.3 cm x 2.5 cm glass slides placed at discrete lateral positions along the central tube were measured by a profilometer (Figure 3). Conductivities were calculated from resistivity measurements using a home-built four-point probe test station. The measured conductivity of a 100-nm thick Cl-PProDOT film on glass slides is 106 S/cm, which is sufficient to qualify this film as a potential electrode material. <strong cl...

Watch this Scientific Journal Video about Reactive Vapor Deposition of Conjugated Polymer Films on Arbitrary Substrates at JoVE.com

Reactive Vapor Deposition of Conjugated Polymer Films on Arbitrary Substrates

This paper presents a protocol for reactive vapor deposition of poly(3,4-ethylenedioxythiophene), poly(3,4-propylenedioxythiophene), and poly(thieno[3,2-b]thiophene) films on glass slides and rough substrates, such as textiles and paper.

We demonstrate a method of conformally coating conjugated polymers on arbitrary substrates using a custom-designed, low-pressure reaction chamber. ...

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33.6K Views.  University of Wisconsin-Madison. This paper presents a protocol for reactive vapor deposition of poly(3,4-ethylenedioxythiophene), poly(3,4-propylenedioxythiophene), and poly(thieno[3,2-b]thiophene) films on glass slides and rough substrates, such as textiles and paper. 

Video: Reactive Vapor Deposition of Conjugated Polymer Films on Arbitrary Substrates

Preparation of Hydrophobic Metal-Organic Frameworks via Plasma Enhanced Chemical Vapor Deposition of Perfluoroalkanes for the Removal of Ammonia

Plasma enhanced chemical vapor deposition (PECVD) of perfluoroalkanes has long been studied for tuning the wetting properties of surfaces. For high surface area microporous materials, such as metal-organic frameworks (MOFs), unique challenges present themselves for PECVD treatments. Herein the protocol for development of a MOF that was previously unstable to humid conditions is presented. The protocol describes the synthesis of Cu-BTC (also known as HKUST-1), the treatment of Cu-BTC with PECVD of perfluoroalkanes, the aging of materials under humid conditions, and the subsequent ammonia microbreakthrough experiments on milligram quantities of microporous materials. Cu-BTC has an extremely high surface area (~1,800 m2/g) when compared to most materials or surfaces that have been previously treated by PECVD methods. Parameters such as chamber pressure and treatment time are extremely important to ensure the perfluoroalkane plasma penetrates to and reacts with the inner MOF surfaces. Furthermore, the protocol for ammonia microbreakthrough experiments set forth here can be utilized for a variety of test gases and microporous materials.

Herein the procedures for plasma enhanced chemical vapor deposition of perfluoroalkanes on microporous materials such as metal-organic frameworks to enhance their stability and hydrophobicity are described. Furthermore, breakthrough testing of milligram quantities of samples is described in detail.

Plasma enhanced chemical vapor deposition (PECVD) of perfluoroalkanes has long been studied for tuning the wetting properties of surfaces. For high ...

Reductive Electropolymerization of a Vinyl-containing Poly-pyridyl Complex on Glassy Carbon and Fluorine-doped Tin Oxide Electrodes

Controllable electrode surface modification is important in a number of fields, especially those with solar fuels applications. Electropolymerization is one surface modification technique that electrodeposits a polymeric film at the surface of an electrode by utilizing an applied potential to initiate the polymerization of substrates in the Helmholtz layer. This useful technique was first established by a Murray-Meyer collaboration at the University of North Carolina at Chapel Hill in the early 1980s and utilized to study numerous physical phenomena of films containing inorganic complexes as the monomeric substrate. Here, we highlight a procedure for coating electrodes with an inorganic complex by performing reductive electropolymerization of the vinyl-containing poly-pyridyl complex onto glassy carbon and fluorine doped tin oxide coated electrodes. Recommendations on electrochemical cell configurations and troubleshooting procedures are included. Although not explicitly described here, oxidative electropolymerization of pyrrole-containing compounds follows similar procedures to vinyl-based reductive electropolymerization but are far less sensitive to oxygen and water.

A procedure for performing reductive electropolymerization of vinyl-containing compounds onto glassy carbon and fluorine doped tin-oxide coated electrodes is presented. Recommendations on electrochemical cell configurations and troubleshooting procedures are included. Although not explicitly described here, oxidative electropolymerization of pyrrole-containing compounds follows similar procedures to vinyl-based reductive electropolymerization.

Controllable electrode surface modification is important in a number of fields, especially those with solar fuels applications. Electropolymerization is ...

Fabrication of Large-area Free-standing Ultrathin Polymer Films

This procedure describes a method for the fabrication of large-area and ultrathin free-standing polymer films. Typically, ultrathin films are prepared using either sacrificial layers, which may damage the film or affect its mechanical properties, or they are made on freshly cleaved mica, a substrate that is difficult to scale. Further, the size of ultrathin film is typically limited to a few square millimeters. In this method, we modify a surface with a polyelectrolyte that alters the strength of adhesion between polymer and deposition substrate. The polyelectrolyte can be shown to remain on the wafer using spectroscopy, and a treated wafer can be used to produce multiple films, indicating that at best minimal amounts of the polyelectrolyte are added to the film. The process has thus far been shown to be limited in scalability only by the size of the coating equipment, and is expected to be readily scalable to industrial processes. In this study, the protocol for making the solutions, preparing the deposition surface, and producing the films is described.

We describe a method for the fabrication of large-area (up to 13 cm diameter) and ultrathin (as thin as 8 nm) polymer films. Instead of using a sacrificial interlayer to delaminate the film from its substrate, we use a self-limiting surface treatment suitable for arbitrarily large areas.

This procedure describes a method for the fabrication of large-area and ultrathin free-standing polymer films.  Typically, ultrathin films are prepared ...

Layer-by-layer Synthesis and Transfer of Freestanding Conjugated Microporous Polymer Nanomembranes

CMP as large surface area materials have attracted growing interest recently, due to their high variability in the incorporation of functional groups in combination with their outstanding thermal and chemical stability, and low densities. However, their insoluble nature causes problems in their processing since usually applied techniques such as spin coating are not available. Especially for membrane applications, where the processing of CMP as thin films is desirable, the processing problems have hindered their commercial application.
Here we describe the interfacial synthesis of CMP thin films on functionalized substrates via molecular layer-by-layer (l-b-l) synthesis. This process allows the preparation of films with desired thickness and composition and even desired composition gradients.
The use of sacrificial supports allows the preparation of freestanding membranes by dissolution of the support after the synthesis. To handle such ultra-thin freestanding membranes the protection with sacrificial coatings showed great promise, to avoid rupture of the nanomembranes. To transfer the nanomembranes to the desired substrate, the coated membranes are upfloated at the air-liquid interface and then transferred via dip coating.

In this paper we describe the interfacial synthesis of conjugated microporous polymers (CMP) on sacrificial substrates, and the dissolution of the substrate for the preparation of freestanding CMP nanomembranes. In addition, we will describe how the fragile nanomembranes can be transferred to other substrates.

CMP as large surface area materials have attracted growing interest recently, due to their high variability in the incorporation of functional groups in ...

Atom Transfer Radical Polymerization of Functionalized Vinyl Monomers Using Perylene as a Visible Light Photocatalyst

A standardized technique for atom transfer radical polymerization of vinyl monomers using perylene as a visible-light photocatalyst is presented. The procedure is performed under an inert atmosphere using air- and water-exclusion techniques. The outcome of the polymerization is affected by the ratios of monomer, initiator, and catalyst used as well as the reaction concentration, solvent, and nature of the light source. Temporal control over the polymerization can be exercised by turning the visible light source off and on. Low dispersities of the resultant polymers as well as the ability to chain-extend to form block copolymers suggest control over the polymerization, while chain end-group analysis provides evidence supporting an atom-transfer radical polymerization mechanism.

A method for the atom transfer radical polymerization of functionalized vinyl monomers using perylene as a visible-light photocatalyst is described.

A standardized technique for atom transfer radical polymerization of vinyl monomers using perylene as a visible-light photocatalyst is presented. The ...

Electroactive Polymer Nanoparticles Exhibiting Photothermal Properties

A method for the synthesis of electroactive polymers is demonstrated, starting with the synthesis of extended conjugation monomers using a three-step process that finishes with Negishi coupling. Negishi coupling is a cross-coupling process in which a chemical precursor is first lithiated, followed by transmetallation with ZnCl2. The resultant organozinc compound can be coupled to a dibrominated aromatic precursor to give the conjugated monomer. Polymer films can be prepared via electropolymerization of the monomer and characterized using cyclic voltammetry and ultraviolet-visible-near infrared (UV-Vis-NIR) spectroscopy. Nanoparticles (NPs) are prepared via emulsion polymerization of the monomer using a two-surfactant system to yield an aqueous dispersion of the polymer NPs. The NPs are characterized using dynamic light scattering, electron microscopy, and UV-Vis-NIR-spectroscopy. Cytocompatibility of NPs is investigated using the cell viability assay. Finally, the NP suspensions are irradiated with a NIR laser to determine their effectiveness as potential materials for photothermal therapy (PTT).

A protocol is presented for the synthesis and preparation of nanoparticles consisting of electroactive polymers.

A method for the synthesis of electroactive polymers is demonstrated, starting with the synthesis of extended conjugation monomers using a three-step ...

Engineering

Fabricating Reactive Surfaces with Brush-like and Crosslinked Films of Azlactone-Functionalized Block Co-Polymers

In this paper, fabrication methods that generate novel surfaces using the azlactone-based block co-polymer, poly (glycidyl methacrylate)-block-poly (vinyl dimethyl azlactone) (PGMA-b-PVDMA), are presented. Due to the high reactivity of azlactone groups towards amine, thiol, and hydroxyl groups, PGMA-b-PVDMA surfaces can be modified with secondary molecules to create chemically or biologically functionalized interfaces for a variety of applications. Previous reports of patterned PGMA-b-PVDMA interfaces have used traditional top-down patterning techniques that generate non-uniform films and poorly controlled background chemistries. Here, we describe customized patterning techniques that enable precise deposition of highly uniform PGMA-b-PVDMA films in backgrounds that are chemically inert or that have biomolecule-repellent properties. Importantly, these methods are designed to deposit PGMA-b-PVDMA films in a manner that completely preserves azlactone functionality through each processing step. Patterned films show well-controlled thicknesses that correspond to polymer brushes (~90 nm) or to highly crosslinked structures (~1-10 &#956;m). Brush patterns are generated using either the parylene lift-off or interface directed assembly methods described and are useful for precise modulation of overall chemical surface reactivity by adjusting either the PGMA-b-PVDMA pattern density or the length of the VDMA block. In contrast, the thick, crosslinked PGMA-b-PVDMA patterns are obtained using a customized micro-contact printing technique and offer the benefit of higher loading or capture of secondary material due to higher surface area to volume ratios. Detailed experimental steps, critical film characterizations, and trouble-shooting guides for each fabrication method are discussed.

Surface fabrication methods for patterned deposition of nanometer thick brushes or micron thick, crosslinked films of an azlactone block co-polymer are reported. Critical experimental steps, representative results, and limitations of each method are discussed. These methods are useful for creating functional interfaces with tailored physical features and tunable surface reactivity.

In this paper, fabrication methods that generate novel surfaces using the azlactone-based block co-polymer, poly (glycidyl methacrylate)-block-poly (vinyl ...

Procedure for the Transfer of Polymer Films Onto Porous Substrates with Minimized Defects

The fabrication of devices containing thin film composite membranes necessitates the transfer of these films onto the surfaces of arbitrary support substrates. Accomplishing this transfer in a highly controlled, mechanized, and reproducible manner can eliminate the creation of macroscale defect structures (e.g., tears, cracks, and wrinkles) within the thin film that compromise device performance and the usable area per sample. Here, we describe a general protocol for the highly controlled and mechanized transfer of a polymeric thin film onto an arbitrary porous support substrate for eventual use as a water filtration membrane device. Specifically, we fabricate a block copolymer (BCP) thin film on top of a sacrificial, water-soluble poly(acrylic acid) (PAA) layer and silicon wafer substrate. We then utilize a custom-designed, 3D-printed transfer tool and drain chamber system to deposit, lift-off, and transfer the BCP thin film onto the center of a porous anodized aluminum oxide (AAO) support disc. The transferred BCP thin film is shown to be consistently placed onto the center of the support surface due to the guidance of the meniscus formed between the water and the 3D-printed plastic drain chamber. We also compare our mechanized transfer-processed thin films to those that have been transferred by hand with the use of tweezers. Optical inspection and image analysis of the transferred thin films from the mechanized process confirm that little-to-no macroscale inhomogeneities or plastic deformations are produced, as compared to the multitude of tears and wrinkles produced from manual transfer by hand. Our results suggest that the proposed strategy for thin film transfer can reduce defects when compared to other methods across many systems and applications.

We present a procedure for highly controlled and wrinkle-free transfer of block copolymer thin films onto porous support substrates using a 3D-printed drain chamber. The drain chamber design is of general relevance to all procedures involving transfer of macromolecular films onto porous substrates, which is normally done by hand in an irreproducible fashion.

The fabrication of devices containing thin film composite membranes necessitates the transfer of these films onto the surfaces of arbitrary support ...

Development of Efficient OLEDs from Solution Deposition

The use of highly efficient organic emitters based on the thermally activated delayed fluorescence (TADF) concept is interesting due to their 100% internal quantum efficiency. Presented here is a solution deposition method for the fabrication of efficient organic light-emitting diodes (OLEDs) based on a TADF emitter in a simple device structure. This fast, low-cost, and efficient process can be used for all OLED emissive layers that follow the host-guest concept. The fundamental steps are described along with necessary information for further reproduction. The goal to establish a general protocol that can be easily adapted for principal organic emitters currently under study and development.

Presented here is a protocol for the fabrication of efficient, simple, solution-deposited organic light-emitting diodes with low roll-off.

The use of highly efficient organic emitters based on the thermally activated delayed fluorescence (TADF) concept is interesting due to their 100% ...

Vapor Phase Deposition of Electroactive Poly(3,4-ethylenedioxythiophene) onto Electrospun Commodity Polymer Nanofibers

This study investigates the preparation of polyacrylonitrile (PAN) nanofibers through electrospinning to create highly porous and strong materials for applications in water purification, electrocatalysis, and biomedicine. The uniformly white PAN nanofiber mats were cut into 2 cm x 2 cm coupons to ensure consistency. After electrospinning, these nanofibers were coated with an electroactive polymer (EAP) using chemical vapor deposition, with iron (III) chloride (FeCl3) serving as an oxidant for polymerizing 3,4-ethylenedioxythiophene (EDOT) into poly(3,4-ethylenedioxythiophene) (PEDOT). The study examined the impact of different FeCl3 concentrations on PEDOT deposition on the PAN coupons. PEDOT deposition led to an increase in coupon weight. Scanning electron microscopy (SEM) revealed increases in the diameter of the nanofibers treated with increasing FeCl3 oxidant concentration, although higher FeCl3&#160;concentrations caused inter-fiber bridging, implying a concomitant decrease in inter-fiber spacing. Energy dispersive X-ray spectroscopy (EDS) was used to confirm the presence of Fe, Cl, and S in the nanofibers, with sulfur content rising with FeCl3&#160;concentration used, suggesting increased PEDOT deposition efficiency with increasing oxidant concentration. Mechanical testing showed that PEDOT-coated PAN fibers had improved tensile strength and toughness in the hydrated state compared to pure PAN nanofibers. These results highlight the crucial role of FeCl3&#160;concentration in influencing the morphology and properties of PAN-PEDOT composites, enhancing their suitability for applications such as water purification, tissue engineering, biosensing, catalysis, and energy storage.

This paper describes a simple technique for coating electrospun PAN nanofibers with electroactive polymers using vapor deposition. The effects of the oxidant FeCl&#8323; on the deposition of poly(3,4-ethylenedioxythiophene) coatings on PAN were investigated to understand and optimize polymer growth, fiber diameter, and overall mechanical strength of the nanofiber mats.

This study investigates the preparation of polyacrylonitrile (PAN) nanofibers through electrospinning to create highly porous and strong materials for ...