The authors acknowledge the Swiss National Science Foundation (SNF) for financial support through project no. 200021_160174.

1. Master Mold Fabrication
<ol>
	<li>Perform the photolithographic fabrication of a 4 inch silicon master mold as described in detail previously19; the master mold used in this study has been fabricated using the same protocol. 
	NOTE: Microfluidic devices are typically fabricated through a multi-step process. The first step is the design of the microfluidic channel using a conventional drawing software. Then, high-resolution film photomasks containing the microfluidic network are produced ...

<ol>
	<li>Cote, A. P., 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=Porous,+crystalline,+covalent+organic+frameworks.">Porous, crystalline, covalent organic frameworks.</a> Science. 310, 1166-1170 (2005).</li><li>Ding, S. Y., Wang, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Covalent+organic+frameworks+(COFs):+from+design+to+applications.">Covalent organic frameworks (COFs): from design to applications.</a> Chem Soc Rev. 42, 548-568 (2013).</li><li>Huang, N., Wang, P., Jiang, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Covalent+organic+frameworks:+a+materials+platform+for+structural+and+functional+designs.">Covalent organic frameworks: a materials platform for structural and functional designs.</a> Nat Rev Mater. 1, 16068 (2016).</li><li>Xu, H., Gao, J., Stable Jiang, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=crystalline,+porous,+covalent+organic+frameworks+as+a+platform+for+chiral+organocatalysts.">crystalline, porous, covalent organic frameworks as a platform for chiral organocatalysts.</a> Nat Chem. 7, 905-912 (2015).</li><li>Wan, S., Guo, J., Kim, J., Ihee, H., Jiang, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Belt-Shaped,+Blue+Luminescent,+and+Semiconducting+Covalent+Organic+Framework.">A Belt-Shaped, Blue Luminescent, and Semiconducting Covalent Organic Framework.</a> Angew Chem Int Edit. 47, 8826-8830 (2008).</li><li>Rodriguez-San-Miguel, D., 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=Crystalline+fibres+of+a+covalent+organic+framework+through+bottom-up+microfluidic+synthesis.">Crystalline fibres of a covalent organic framework through bottom-up microfluidic synthesis.</a> Chem Commun. 52, 9212-9215 (2016).</li><li>Bisbey, R. P., DeBlase, C. R., Smith, B. J., Dichtel, W. 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J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tailoring+microporosity+in+covalent+organic+frameworks.">Tailoring microporosity in covalent organic frameworks.</a> Adv Mater. 20, 2741-2746 (2008).</li><li>Hasegawa, S., 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=Three-dimensional+porous+coordination+polymer+functionalized+with+amide+groups+based+on+tridentate+ligand:+Selective+sorption+and+catalysis.">Three-dimensional porous coordination polymer functionalized with amide groups based on tridentate ligand: Selective sorption and catalysis.</a> J Am Chem Soc. 129, 2607-2614 (2007).</li><li>Das, G., 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+sensing+in+two+dimensional+porous+covalent+organic+nanosheets.">Chemical sensing in two dimensional porous covalent organic nanosheets.</a> Chem Sci. 6, 3931-3939 (2015).</li><li>Guo, 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=Conjugated+organic+framework+with+three-dimensionally+ordered+stable+structure+and+delocalized+pi+clouds.">Conjugated organic framework with three-dimensionally ordered stable structure and delocalized pi clouds.</a> Nat Commun. 4, 2736 (2013).</li><li>Furukawa, H., Yaghi, O. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Storage+of+Hydrogen,+Methane,+and+Carbon+Dioxide+in+Highly+Porous+Covalent+Organic+Frameworks+for+Clean+Energy+Applications.">Storage of Hydrogen, Methane, and Carbon Dioxide in Highly Porous Covalent Organic Frameworks for Clean Energy Applications.</a> J Am Chem Soc. 131, 8875-8883 (2009).</li><li>Xu, F., 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=Electrochemically+active,+crystalline,+mesoporous+covalent+organic+frameworks+on+carbon+nanotubes+for+synergistic+lithium-ion+battery+energy+storage.">Electrochemically active, crystalline, mesoporous covalent organic frameworks on carbon nanotubes for synergistic lithium-ion battery energy storage.</a> Sci Rep-Uk. 5, 8225 (2015).</li><li>El-Kaderi, H. 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=Designed+synthesis+of+3D+covalent+organic+frameworks.">Designed synthesis of 3D covalent organic frameworks.</a> Science. 316, 268-272 (2007).</li><li>Ruigomez, A. D., 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+On-Surface+Patterning+of+a+Crystalline+Laminar+Covalent+Organic+Framework+Synthesized+at+Room+Temperature.">Direct On-Surface Patterning of a Crystalline Laminar Covalent Organic Framework Synthesized at Room Temperature.</a> Chem Eur J. 21, 10666-10670 (2015).</li><li>Segura, J. L., Mancheno, M. J., Zamora, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Covalent+organic+frameworks+based+on+Schiff-base+chemistry:+synthesis,+properties+and+potential+applications.">Covalent organic frameworks based on Schiff-base chemistry: synthesis, properties and potential applications.</a> Chem Soc Rev. 45, 5635-5671 (2016).</li><li>Abrishamkar, A., 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=Microfluidic+Pneumatic+Cages:+A+Novel+Approach+for+In-chip+Crystal+Trapping,+Manipulation+and+Controlled+Chemical+Treatment.">Microfluidic Pneumatic Cages: A Novel Approach for In-chip Crystal Trapping, Manipulation and Controlled Chemical Treatment.</a> J Vis Exp. (113), e54193 (2016).</li><li>Duffy, D. C., McDonald, J. C., Schueller, O. J. A., Whitesides, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+prototyping+of+microfluidic+systems+in+poly(dimethylsiloxane).">Rapid prototyping of microfluidic systems in poly(dimethylsiloxane).</a> Anal Chem. 70, 4974-4984 (1998).</li><li>Rubio-Martinez, 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=Freezing+the+Nonclassical+Crystal+Growth+of+a+Coordination+Polymer+Using+Controlled+Dynamic+Gradients.">Freezing the Nonclassical Crystal Growth of a Coordination Polymer Using Controlled Dynamic Gradients.</a> Adv Mater. 28, 8150-8155 (2016).</li><li>Liu, 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=A+Catalytic+Chiral+Gel+Microfluidic+Reactor+Assembled+via+Dynamic+Covalent+Chemistry.">A Catalytic Chiral Gel Microfluidic Reactor Assembled via Dynamic Covalent Chemistry.</a> Chem Sci. 6, 2292-2296 (2015).</li><li>Puigmarti-Luis, 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=Stepwise+Template+Growth+of+Functional+Nanowires+from+an+Amino+Acid-Supported+Framework+in+a+Microfluidic+Chip.">Stepwise Template Growth of Functional Nanowires from an Amino Acid-Supported Framework in a Microfluidic Chip.</a> ACS Nano. 8 (1), 818-826 (2014).</li></ol>

The microfluidic-based synthetic method reported here provides a novel and simple approach for direct printing of COF materials on surfaces. Synthesis is performed using a single-layer microfluidic device, comprised of a microfluidic PDMS chip bonded to a glass coverslip. The fabrication of the microfluidic device can be achieved through conventional casting of PDMS against a silicon master mold and subsequently bonding the PDMS with the imprinted microchannels against a glass coverslip.
For t...

Covalent organic frameworks (COFs) are a well-established class of porous and crystalline material in which the organic building blocks are firmly held together by covalent bonds1,2,3,4,5. COFs are typically assembled following supramolecular chemistry principles, where the constituent molecular building blocks are selectively reacted to define a final and predetermined porous assembly. Such an approach allows the synthesis of materials with controlled and ordered structure (e.g.,with defined pore dimensions) and composition3,6,7,8. Compared to other porous materials, COFs are unique since they are comprised of light elements (C, H, B, N and O) and have tunable porosities1,5. Inspired by these unique and intrinsic characteristics, COFs have been assessed for potential application in chemical separations9, gas storage10and catalysis11, sensors12, optoelectronics13, clean energy technologies14 and electrochemical energy devices15.
To date, the vast majority of methods used for the preparation of COF materials are based on solvothermal self-condensation and co-condensation reactions, where high temperatures and pressures are the standard. Although COFs are thermally robust, they commonly suffer from limited processability, i.e., COFs are usually insoluble and unprocessable crystalline powders, and this significantly limits their use in a range of potential and practical applications2,6,8,16,17. Despite the remarkable progress made in COF synthesis, a major challenge in the field is to develop a method enabling the preparation of COFs in appropriate reaction conditions (e.g., temperature and pressure), which can then facilitate their processability on surfaces.
Recently, studies have shown that Shiff-base chemistry can be used to synthesize an imine-based COF at room temperature. The COF produced, named RT-COF-1, forms due to the fast and efficient reaction between 1,3,5-tris(4-aminophenyl)benzene (TAPB) and 1,3,5-benzenetricarbaldehyde (BTCA)17 (Figure 1A). The efficacy of this synthetic method was demonstrated by the direct printing of micron and submicron patterns of RT-COF-1 on both rigid and flexible surfaces using lithography or inkjet printing techniques. More recently, and making use of microfluidics, we have demonstrated an effective approach for the continuous synthesis of fibers of the same imine-based COF hereafter called MF-COF6. Unlike other reported synthetic approaches for the generation of COFs18, this microfluidic-based synthetic method enabled the rapid synthesis of MF-COF fibers at ambient temperatures and pressures within a few seconds. Furthermore, and owing to the mechanical stability of the synthesized MF-COF fibers, we have demonstrated how such microfluidic-based method can enable the direct printing of 2D and 3D structures on surfaces. Herein, we demonstrate that this method can be used to draw COF structures on various surfaces having different chemical and physical properties. We believe that this novel method opens new avenues for the well-controlled patterning and direct printing of COFs in different orientations and on various surfaces.

<table border="0" cellpadding="0" cellspacing="0" width="1147">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:336px;">High resolution film masks</td>
			<td style="width:252px;">Microlitho, UK</td>
			<td style="width:189px;">-</td>
			<td style="width:371px;">Features down to 5um</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:336px;">Silicon wafers</td>
			<td style="width:252px;">Silicon Materials Inc., Germany</td>
			<td style="width:189px;">4&#34; Silicon Wafers</td>
			<td>Front surface: polished, back surface: etched</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:336px;">Silicone Elastomer KIT (PDMS)</td>
			<td style="width:252px;">Dow Corning, USA</td>
			<td style="width:189px;">Sylgard 184</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Chlorotrimethylsilane</td>
			<td style="width:252px;">Sigma-Aldrich, Switzerland</td>
			<td style="width:189px;">386529</td>
			<td>&#8805;97%, CAUTION: Handle it only under fume hood.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:336px;">Biopsy puncher</td>
			<td style="width:252px;">Miltex GmBH, Germany</td>
			<td style="width:189px;">33-31A-P/25</td>
			<td>1.5 mm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:336px;">Glass coverslip</td>
			<td style="width:252px;">Menzel-Glaser, Germany</td>
			<td style="width:189px;">BB024040SC</td>
			<td>24 mm &#215; 40 mm, #5</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:336px;">Plasma generator instrument</td>
			<td style="width:252px;">Diener</td>
			<td style="width:189px;">Zepto B</td>
			<td>Frequency: 40 kHz and plasma generator power: 0-30 W</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:336px;">PTFE tubing</td>
			<td style="width:252px;">PKM SA, Switzerland</td>
			<td style="width:189px;">AWG-TFS-XXX</td>
			<td style="width:371px;">AWG 20TFS, roll of 100 m</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:336px;">neMESYS Syringe Pumps</td>
			<td style="width:252px;">Cetoni GmbH, Germany</td>
			<td style="width:189px;">Low Pressure (290N)</td>
			<td>-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:336px;">Disposable Cup</td>
			<td style="width:252px;">Semadeni, Switzerland</td>
			<td style="width:189px;">8323</td>
			<td>PS, 200 ml</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:336px;">Plastic Spatula</td>
			<td style="width:252px;">Semadeni, Switzerland</td>
			<td style="width:189px;">3340</td>
			<td>L &#215; W : 135 mm x 14 mm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:336px;">Disposable Scalpels</td>
			<td style="width:252px;">B. Braun, Switzerland</td>
			<td style="width:189px;">233-5320</td>
			<td>Nr. 20</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:336px;">Disposable Syringes</td>
			<td style="width:252px;">VWR, Switzerland</td>
			<td style="width:189px;">613-3951</td>
			<td>5 ml, Discardit II</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:336px;">Acetic Acid</td>
			<td style="width:252px;">Sigma-Aldrich, Switzerland</td>
			<td style="width:189px;">695092-500</td>
			<td>&#62;=99.7%, CAUTION: Handle it only under fume hood.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:336px;">1,3,5-benzenetricarbaldehyde</td>
			<td style="width:252px;">Aldrich-Fine Chemicals</td>
			<td style="width:189px;">753491</td>
			<td>97%</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:336px;">1,3,5-Tris(4-aminophenyl)benzene</td>
			<td style="width:252px;">Tokyo Chemical Industry</td>
			<td style="width:189px;">T2728-5G</td>
			<td>&#62;93.0%</td>
		</tr>
	</tbody>
</table>

microfluidic-based synthesis of covalent organic frameworks (cofs): a tool for continuous production of cof fibers and direct printing on a surface

Covalent Organic Frameworks (COFs) are a class of porous covalent materials which are frequently synthesized as unprocessable crystalline powders. The first COF was reported in 2005 with much effort centered on the establishment of new synthetic routes for its preparation. To date, most available synthetic methods for COF synthesis are based on bulk mixing under solvothermal conditions. Therefore, there is increasing interest in developing systematic protocols for COF synthesis that provide for fine control over reaction conditions and improve COF processability on surfaces, which is essential for their use in practical applications. Herein, we present a novel microfluidic-based method for COF synthesis where the reaction between two constituent building blocks, 1,3,5-benzenetricarbaldehyde (BTCA) and 1,3,5-tris(4-aminophenyl)benzene (TAPB), takes place under controlled diffusion conditions and at room temperature. Using such an approach yields sponge-like, crystalline fibers of a COF material, hereafter called MF-COF. The mechanical properties of MF-COF and the dynamic nature of the approach allow the continuous production of MF-COF fibers and their direct printing onto surfaces. The general method opens new potential applications requiring advanced printing of 2D or 3D COF structures on flexible or rigid surfaces.

The microfluidic device used in our investigations is fabricated using conventional PDMS replica molding20 and incorporates four microfluidic inlet channels that merge into a main microchannel. The final microfluidic device consists of a structured PDMS layer and a glass coverslip used to close the imprinted microchannels, as shown in Figure 1B.
<img alt="Figure 1" class="xfi...

Watch this Scientific Journal Video about Microfluidic-based Synthesis of Covalent Organic Frameworks COFs: A Tool for Continuous Production of COF Fibers and Direct Printing on a Surface at JoVE.com

Microfluidic-based Synthesis of Covalent Organic Frameworks COFs: A Tool for Continuous Production of COF Fibers and Direct Printing on a Surface

We present a novel microfluidic-based method for synthesis of covalent organic frameworks (COFs). We demonstrate how this approach can be used to produce continuous COF fibers, and also 2D or 3D COF structures on surfaces.

Microfluidic-based Synthesis of Covalent Organic Frameworks (COFs): A Tool for Continuous Production of COF Fibers and Direct Printing on a Surface

Covalent Organic Frameworks (COFs) are a class of porous covalent materials which are frequently synthesized as unprocessable crystalline powders. The ...

The overall goal of this approach is to demonstrate how a microfluidic-based platform can be used to produce continuous fibers of covalent organic frameworks that can be printed on surfaces to create 2D and 3D structures. Despite the remarkable progress in the synthesis of covalent and organic frameworks, developing a method to facilitate the process ability of these materials remains a challenge, which makes this approach very promising. This method effectively contributes to the field of crystalline materials through introduction of a noble, synthetic approach to produce continuous fibers of covalent and organic frameworks, thereby enhancing their process ability.To begin the device fabrication, in a fume hood, place a silicon master mold fabricated from a four inch silicon wafer in a vacuum desiccator. Dispatch 100 microliters of trimethylsilyl chloride into a glass vial and place the vial in the vacuum desiccator. Close the desiccator and put it under vacuum.Allow the trimethylsilyl chloride vapor to deposit on the master mold surface for one hour. Then, slowly vent the desiccator. Remove the silanised master mold and close the desiccator.Store the silanised mold in a closed container or in a laminal flow hood. Next, in a disposable cup, use a plastic spatula to mix together PDMS elastomer and curing agent in a 10:0.9 weight ratio. De-gass the mixture in a vacuum desiccator for 30 minutes.Then, carefully place four PTFE frames on the master mold, so that each frame encloses a single pattern on the mold. Pour the PTMS mixture into the frames and over the mold until full. Cure the PDMS in an oven at 70 degrees celsius for two hours, then remove the mold from the oven and allow the PDMS chips to cool to room temperature in the laminar flow hood.Once cool, carefully separate the frames from the mold by hand. Gently slide the PDMS chips from the frame. Use a 1.5 millimeter biopsy puncture to punch inlet and outlet holes at the end to the micro-fluidic channels in the chips.Trim excess PDMS from the chips and clean the chip and cover slip surfaces with adhesive tape. Place the clean chips in a plasma generator with the open channels facing up, along with four glass cover slips. Evacuate the sample chamber and run the generator for one minute.Then, vent the chamber and remove the plasma treated chips and cover slips. Bond each chip to a treated cover slip with the open channels faced down by gently pressing the chip onto the cover slip. Place the resulting micro-fluidic chips in an oven at 70 degree celsius for at least four hours to strengthen the bonding between the PDMS and the glass.To begin preparing for the synthesis, draw three milliliters of 40 milli molar BTCA in acetic acid into a five milliliter syringe. Draw three milliliters of 40 milli molar TAPB in acetic acid into another five milliliter syringe. Use PTFE tubing with an inner diameter of 0.8 millimeters and connect the tubings from one side to the syringes.Mount both syringes on a syringe pump. Next, fill two five milliliters syringes with acetic acid, use PTFE tubing with an inner diameter of 0.8 millimeters and connect the tubings from one side to the syringes. Secure these syringes into syringe pumps.Then, obtain a single layer four channel micro-fluidic chip. Connect the other side of the PTFE tubing to the inlets of the micro-fluidic device and connect the syringes to the outer channel inlets. Connect the 15 centimeter length of PTFE tubing to the chip outlet.Fix the end of the tubing in a 60 millimeter petri dish containing 10 milliliters of acetic acid. Place a glass cover slip next to the petri dish. Set each syringe pump to a flow rate of 100 microliters per minute and start the pumps.Wait one minute for the flows to stabilize while monitoring the MF-COF fiber formation in the chip. Change the flow rates of the acetic acid and check the outlet tubing. If the sheath flows of acetic acid are too high relative to the BTCA and TAPB flows, the MF-COF fiber's microstructure suspension will be too dilute to form a continuous fiber.If the sheath flows of acetic acid are too low relative to the reagent flows, the high concentration of MF-COF fibers will clog the outlet tubing. Set each syringe to a flow rate of 100 microliters per minute and wait one minute for the flows to stabilize. Once the flows have stabilized and the continuous MF-COF fiber reaches the end of the outlet tube, hold the end of the tube, a few millimeters above the surface.Slowly move the tube to draw an MF-COF structure. The suitable mechanical properties drive from the microscopic organization of MF-COF, allow the use of MF-COF fibers for conformal creating of 2D and 3D structures on saraphasis. Slowly raise the tube two to three centimeters from the surface to produce a free standing stable MF-COF fiber.Slowly lower the tube to continue drawing a 2D or 3D structure directly on the cover slip. MF-COF fibers were synthesized from TAPB and BTCA, using a four channel micro-fluidic device. Scanning electron microscopy showed that the fibers consisted of inter-connected micro and nano fibers in 3D sponge-like, porous structures that grant the mechanical properties needed to print 2D and 3D structures.2D MF-COF structures were printed on glass surfaces by drawing shapes as the fiber was continuously generated. The relative precision of the printing process was further highlighted in writing experiments on glass. The fibers did not merge when patterned over each other, allowing printing of 3D structures.In addition to glass, MF-COF structures were printed on tissue paper, cardboard, aluminum foil and polystyrene. While attempting this procedure, remember to perform all the steps for the fabrication of the micro-fluidic device inside the laminar flow hood and all the synthesis steps that involve handling of acetic acid under a fume hood. After its development, this technique paves the way for the researchers in the field of crystalline materials to explore new technological applications requiring advance patterning of 2D and 3D structures made of crystalline fibers and various seraphasis.After watching this video, you should have a good understanding of how to synthesize the continuous fiber of covalent, organic frameworks using a micro-fluidic platform and how to print a produced fiber and seraphasis to make 2D and 3D structures.

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13.1K vistas.  ETH Zurich. The overall goal of this approach is to demonstrate how a microfluidic-based platform can be used to produce continuous fibers of covalent organic frameworks that can be printed on surfaces to create 2D and 3D structures. Despite the remarkable progress in the synthesis of covalent and organic frameworks, developing a method to facilitate the process ability of these materials remains a challenge, which makes this approach very promising. This method effectively contributes to the field of cr...

Video: Microfluidic-based Synthesis of Covalent Organic Frameworks COFs: A Tool for Continuous Production of COF Fibers and Direct Printing on a Surface