Name: layer-by-layer synthesis and transfer of freestanding conjugated microporous polymer nanomembranes
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1.合成的CMP薄膜通过顺序加入<ol><li>金云母自组装单层（SAM）官能化。 <ol><li>制备11-硫代乙酰基十一烷酸炔丙基酰胺14在乙醇1mM的溶液（SAM-溶液）。混合使用超声波浴，直到解决方案是明确的。用铝箔避光的瓶子。 </li><li>获取在氩气中金云母片。从储存容器撤走后直接浸入云母晶片18小时在SAM的溶液。 </li><li>取所制备的Au-云母晶片出SAM-溶液，冲洗，在氮气流下乙醇和干燥。之后存储从光中，在惰性气体保护基板。 </li></ol></li><li>前体的解决方案。 <ol><li>称量18.64毫克铜催化剂（四（乙腈）铜（I）​​六氟磷酸盐），20.83毫克tetraphenylmethane（TPM）-alkyne和24.22毫克TPM的叠氮化物和填充每个组件到一个单独的Schlenk烧瓶中。参见图1为TPM-炔和TPM叠氮化物，在合成与参考例15所述 。疏散和填充有惰性气体（N 2或氩气）的3倍。 </li><li>加25毫升的水 - 自由四氢呋喃（THF）以每Schlenk烧瓶。用铝箔避光与TPM的叠氮化物和TPM炔烧瓶。 </li></ol></li><li>为CMP制造准备设备。 注意:合成装置示于图2。 <ol><li>使用250ml的单颈圆底烧瓶中。 130毫升THF填写。把准备好的基材涂炔样品室终止SAM。使用一个样本保持器，使得衬底垂直站立。 </li><li>经由在回流冷却器的顶部的交界处连接装置向舒伦克线。 </li><li>疏散和通风用惰性气体的3倍。 </li></ol></li><li>顺序加入在惰性条件下。 <ol><li>加热器设定为90℃，并等到THF为重励磁。 </li><li>让出THF来自出口，在样品室底部的样品室。关闭出口。 </li><li>给予1毫升制备的TPM的叠氮化物溶液和0.5ml经由螺旋盖与隔膜的铜（Ⅰ）催化剂溶液到样品室。使用注射器的中空针的溶液依次从Schlenk烧瓶转移到反应装置。注意:序列没有影响到反应中。 </li><li>等待大约30分钟。 </li><li>让出在样品隔室的底部的反应溶液中的出口。关闭出口并收集冷凝THF冲洗样品。等待大约30分钟。 </li><li>让出了出口处的冲洗溶液在样品隔室的底部。关闭出口。 </li><li>给予1毫升制备的TPM的炔溶液和0.5ml经由螺旋盖与隔膜的铜（Ⅰ）催化剂溶液到样品室。用注射器具有中空针溶液依次从Schlenk烧瓶转移到反应装置。注意:序列没有影响到反应中。 </li><li>等待大约30分钟。 </li><li>让出在样品隔室的底部的反应溶液中的出口。关闭出口并收集冷凝THF冲洗样品。等待大约30分钟。 </li><li>重复步骤1.4.3至1.4.9直至达到各层的期望量。注:一层是约1纳米厚。 </li><li>取出CMP包覆云母基材，以THF，乙醇冲洗并晾干在氮气流。 </li></ol></li></ol> 2.将CMP纳米薄膜的<ol><li>有机玻璃（PMMA）溶液。 <ol><li>制备的4％（重量）聚甲基丙烯酸甲酯（M 996 kDa的）在乙酸乙酯中的溶液。使用聚甲基丙烯酸甲酯超声波浴直到溶液是澄清溶解。 </li></ol></li><li>聚甲基丙烯酸甲酯解旋涂。 <ol><li>设定旋涂至RaMP时间内从0到4000转10秒，保温时间40秒，减速时间10秒，从4000至0 rpm。 </li><li>放置在旋涂器在CMP被覆云母基板和放聚甲基​​丙烯酸甲酯溶液的晶片上，直到它被完全覆盖。启动旋涂机。 </li><li>后旋涂结束后，把样品5分钟的加热板上在90℃。 </li><li>从涂覆的云母基底的每一边缘切断1毫米。使用剪刀切割边缘。 </li></ol></li><li> PMMA转移涂层CMP纳米薄膜。 <ol><li>准备的我2 / KI / H 2溶液0（1:4:40米/ M / M）和Ki / H 2 O（1:10 M / M）。 </li><li>填写150ml的结晶皿中的I 2 / KI H 2 O解决方案，并利用100毫升结晶皿的KI / H 2 O解决方案。把PMMA涂CMP金云母基材，与云母接触到的解决方案，在我2 / KI / H 2 O解决方案之上。要小心，它不下沉。至少等待5分钟。 </li><li>放聚甲基丙烯酸甲酯涂CMP金云母基板从I 2 / KI / H 2 O的溶液在碘化钾/ H 2 O的溶液的上面，云母在接触到溶液中。要小心，它不下沉。至少等待5分钟。 </li><li>填蒸馏水在250毫升结晶皿。剥去从云母的PMMA / CMP /金膜。通过稍微浸入衬底，从一个边缘开始，在蒸馏水中做到这一点。保持基板，使得云母指向的水。注意:程序示于图3。 </li><li>浸涂的PMMA / CMP /在硅晶片上金。通过与晶片接近PMMA / CMP /金缓慢，直到它触及的游泳PMMA / CMP /金膜边缘执行此操作。拉出硅晶片缓慢，一旦Si晶片是在用PMMA / CMP /金膜接触。 </li><li>从硅晶片剥离聚甲基丙烯酸甲酯/ CMP /金薄膜关闭。稍微浸泡基材，从一开始的编辑这样做GE，在我2 / KI / H 2 O解决方案。等待15分钟。 </li><li>后金被完全蚀刻时，通过在硅晶片上的PMMA / CMP膜转移到水中。等待15分钟。 </li><li>重复步骤2.3.7三次，用水洗涤该膜。 </li><li>经洗涤的聚甲基丙烯酸甲酯/ CMP膜转移到所需的基材，例如显微镜载玻片或金涂覆的硅晶片上，通过在步骤2.3.5中提到的方法。让空气中的聚甲基丙烯酸甲酯/ CMP基板干燥至少2小时。 </li></ol></li><li>溶聚甲基丙烯酸甲酯。 <ol><li>放聚甲基丙烯酸甲酯/ CMP衬底丙酮。等待30分钟。取出基板，并用丙酮冲洗。 </li><li>重复步骤2.4.1三次。 </li><li>让CMP基材干燥至少2小时。 </li></ol></li></ol>

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The authors have nothing to disclose.

对于在CMP-膜的合成催化剂的溶液必须是新鲜。破碎的催化剂（即，氧化的）由溶液的蓝色着色指示。新鲜的溶液是无色的。 一个关键点是旋涂PMMA后裁切云母基材的边缘。另外在基板的缺陷应该削减， 即，每个点是聚甲基丙烯酸甲酯可以来缺失金层，因为在与云母基板接触。否则金层不能从云母基板容易剥离。另外关于金层的云母基材支队，支队开始在?...

The preparation of ultra-thin polymer membranes is of high interest for applications in gas separation and nanofiltration. Challenges in the synthesis are represented by (a) the control of the membrane thickness and the homogeneity and (b) transfer of such fragile membranes. To overcome challenge (a), molecular layer-by-layer synthesis1 has shown great promise in controlling the thickness and homogeneity of thin films grown at the solid-liquid interface.2,3 Controlling the number of layers linearly controls the film thickness. The l-b-l method has been successfully used to fabricate surface mounted metal organic frameworks (SURMOFs),4-7 also the synthesis of thin polymer films via l-b-l reaction of polymer chains was demonstrated.8 The challenge (b) concerns the handling of these ultra-thin membranes. To avoid rupture or wrinkling of the nanomembranes sacrificial supports of coatings have shown great promise. 9
Here we will present a detailed protocol for synthesis of conjugated microporous polymer (CMP)10-13 thin films through sequential addition of the molecular building blocks, with desired thickness and composition. The preparation of free-standing CMP nanomembranes is achieved by using a sacrificial support. To handle and transfer the CMP nanomembranes to other supports we will describe a simple protocol to protect the membranes with sacrificial coatings and their upfloating to the liquid air interface and subsequent transfer using dip-coating.

<table><tbody><tr><td>Acetone</td><td>VWR BDH Prolabo</td><td>20066.330</td><td>AnalR NORMAPUR</td></tr><tr><td>Potassium iodide</td><td>VWR BDH Prolabo</td><td>26846.292</td><td>AnalR NORMAPUR</td></tr><tr><td>Ethyl acetate</td><td>VWR BDH Prolabo</td><td>23882.321</td><td>AnalR NORMAPUR</td></tr><tr><td>Tetrahydrofuran (THF)</td><td>VWR BDH Prolabo</td><td>28559.320</td><td>HiPerSolv CHROMANORM</td></tr><tr><td>THF waterfree</td><td>Merck Millipore</td><td>1.08107.1001</td><td>SeccoSolv</td></tr><tr><td>Iodine</td><td>Sigma-Aldrich</td><td>20,777-2</td><td></td></tr><tr><td>Tetrakis(acetonitrile) copper(I) hexafluoro-phosphate</td><td>Sigma-Aldrich</td><td>346276-5G</td><td></td></tr><tr><td>Poly(methyl methacrylate) 996 kDa (PMMA)</td><td>Sigma-Aldrich</td><td>182265-25G</td><td></td></tr><tr><td>1.1.1.1 Methanetetrayltetrakis(4-azidobenzene) (TPM-azide)</td><td></td><td></td><td>Provided by AK Prof. Br&amp;auml;se. Institute of organic chemistry, Karlsruhe Institute of Technology. Synthesized according to &lt;sup&gt;9&lt;/sup&gt;.</td></tr><tr><td>1.1.1.1 Methanetetrayltetrakis(4-ethinylenebenzene) (TPM-alkyne)</td><td></td><td></td><td>Provided by AK Prof. Br&amp;auml;se. Institute of organic chemistry, Karlsruhe Institute of Technology. Synthesized according to &lt;sup&gt;9&lt;/sup&gt;.</td></tr><tr><td>11-thioacetyl-undecaneacid propargylamide</td><td></td><td></td><td>Provided by AK Prof. Br&amp;auml;se. Institute of organic chemistry, Karlsruhe Institute of Technology. Synthesized according to &lt;sup&gt;8&lt;/sup&gt;.</td></tr><tr><td>gold/titan coated silicium-wafer</td><td>Georg Albert PVD, 76857 Silz, Germany</td><td></td><td></td></tr><tr><td>gold coated mica</td><td>Georg Albert PVD, 76857 Silz, Germany</td><td></td><td></td></tr></tbody></table>

layer-by-layer synthesis and transfer of freestanding conjugated microporous polymer nanomembranes

CMP作为大表面积材料已经引起了近来越来越大的兴趣，由于它们的高变异性的官能团的组合掺入其优异的热和化学稳定性，和低的密度。然而，它们的不溶性质会产生问题在它们的处理，因为，如旋涂通常适用技术是不可用的。特别是对于膜应用，其中CMP为薄膜的处理是可取的，则处理问题阻碍他们的商业应用。 这里，我们描述在通过分子层 - 层（LBL）合成官能化基底的CMP薄膜的界面合成。此过程允许具有所需厚度和组成，甚至所需组成梯度的薄膜的制备。 使用牺牲载体允许通过后溶解载体的独立式膜的制备的合成。为了处理这种超薄独立的膜与牺牲涂料的保护表现出极大的承诺，避免了纳米薄膜破裂。到的纳米薄膜转移到期望的基材，所述涂覆的膜upfloated在空气 - 液体界面，然后通过浸涂传送。

膜的特征在于红外反射吸收光谱（IRRAS）。16 图4示出 IRRA谱从在CMP膜转移至金晶片。由芳族骨架的振动典型峰是一千六百○五-1，一千五百十五-1和1412厘米-1。未反应的炔和叠氮基团可通过特征频带在2125厘米-1和一二二七-1可以观察到。 图5显示的扫描电子显微镜（SEM）图像。的独立式膜是清晰可见。 <p class="jove_content" fo:...

Watch this Scientific Journal Video about Layer-by-layer Synthesis and Transfer of Freestanding Conjugated Microporous Polymer Nanomembranes at JoVE.com

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

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.

层 - 层的合成和独立式共轭微孔聚合物纳米薄膜的转移

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

layer-layer-synthesis-transfer-freestanding-conjugated-microporous

Universidad San Sebastian

Research

JoVE Journal

Chemistry

9.3K 次观看.  Karlsruhe Institute of Technology. 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.

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

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.

大面积的制造自立性的超薄聚合物薄膜

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

科研

化学

Preparation of Highly Porous Coordination Polymer Coatings on Macroporous Polymer Monoliths for Enhanced Enrichment of Phosphopeptides

We describe a protocol for the preparation of hybrid materials based on highly porous coordination polymer coatings on the internal surface of macroporous polymer monoliths. The developed approach is based on the preparation of a macroporous polymer containing carboxylic acid functional groups and the subsequent step-by-step solution-based controlled growth of a layer of a porous coordination polymer on the surface of the pores of the polymer monolith. The prepared metal-organic polymer hybrid has a high specific micropore surface area. The amount of iron(III) sites is enhanced through metal-organic coordination on the surface of the pores of the functional polymer support. The increase of metal sites is related to the number of iterations of the coating process.
The developed preparation scheme is easily adapted to a capillary column format. The functional porous polymer is prepared as a self-contained single-block porous monolith within the capillary, yielding a flow-through separation device with excellent flow permeability and modest back-pressure. The metal-organic polymer hybrid column showed excellent performance for the enrichment of phosphopeptides from digested proteins and their subsequent detection using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The presented experimental protocol is highly versatile, and can be easily implemented to different organic polymer supports and coatings with a plethora of porous coordination polymers and metal-organic frameworks for multiple purification and/or separation applications.

A procedure for the preparation of porous hybrid separation media composed of a macroporous polymer monolith internally coated by a high surface area microporous coordination polymer is presented.

对磷酸增强富集制备高度多孔配位聚合物涂层的孔聚合物石柱的

We describe a protocol for the preparation of hybrid materials based on highly porous coordination polymer coatings on the internal surface of macroporous ...

Fabrication of the Thermoplastic Microfluidic Channels

In our lab, we have successfully isolated nucleic acids directly from microliter and submicroliter volumes of human blood, urine and stool using polymer/nanoparticle composite microscale lysis and solid phase extraction columns. The recovered samples are concentrated, small volume samples that are PCRable, without any additional cleanup. Here, we demonstrate how to fabricate thermoplastic microfluidic chips using hot embossing and heat sealing. Then, we demonstrate how to use in situ light directed surface grafting and polymerization through the sealed chip to form the composite solid phase columns. We demonstrate grafting and polymerization of a carbon nanotube/polymer composite column for bacterial cell lysis. We then show the lysis process followed by solid phase extraction of nucleic acids from the sample on chip using a silica/polymer composite column. The attached protocols contain detailed instructions on how to make both lysis and solid phase extraction columns.

Here we demonstrate how to fabricate thermoplastic microfluidic chips using hot embossing and heat sealing. Then we demonstrate how to use in situ light directed surface grafting and polymerization through the sealed chip to form the composite solid phase columns.

制备热塑性微流体通道

In our lab, we have successfully isolated nucleic acids directly from microliter and submicroliter volumes of human blood, urine and stool using ...

生物学

Facile Synthesis of Worm-like Micelles by Visible Light Mediated Dispersion Polymerization Using Photoredox Catalyst

Presented herein is a protocol for the facile synthesis of worm-like micelles by visible light mediated dispersion polymerization. This approach begins with the synthesis of a hydrophilic poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA) homopolymer using reversible addition-fragmentation chain-transfer (RAFT) polymerization. Under mild visible light irradiation (&#955; = 460 nm, 0.7 mW/cm2), this macro-chain transfer agent (macro-CTA) in the presence of a ruthenium based photoredox catalyst, Ru(bpy)3Cl2 can be chain extended with a second monomer to form a well-defined block copolymer in a process known as Photoinduced Electron Transfer RAFT (PET-RAFT). When PET-RAFT is used to chain extend POEGMA with benzyl methacrylate (BzMA) in ethanol (EtOH), polymeric nanoparticles with different morphologies are formed in situ according to a polymerization-induced self-assembly (PISA) mechanism. Self-assembly into nanoparticles presenting POEGMA chains at the corona and poly(benzyl methacrylate) (PBzMA) chains in the core occurs in situ due to the growing insolubility of the PBzMA block in ethanol. Interestingly, the formation of highly pure worm-like micelles can be readily monitored by observing the onset of a highly viscous gel in situ due to nanoparticle entanglements occurring during the polymerization. This process thereby allows for a more reproducible synthesis of worm-like micelles simply by monitoring the solution viscosity during the course of the polymerization. In addition, the light stimulus can be intermittently applied in an ON/OFF manner demonstrating temporal control over the nanoparticle morphology.

This article describes a process for producing polymeric self-assembled nanoparticles using visible light mediated dispersion polymerization. Using low energy visible light to control the polymerization allows for the reproducible formation of self-assembled worm-like micelles at high solids content.

使用Photoredox催化剂蠕虫状胶束的简便合成可见光介导的分散聚合

Presented herein is a protocol for the facile synthesis of worm-like micelles by visible light mediated dispersion polymerization. This approach begins ...

Creating Sub-50 Nm Nanofluidic Junctions in PDMS Microfluidic Chip via Self-Assembly Process of Colloidal Particles

Polydimethylsiloxane (PDMS) is the prevailing building material to make microfluidic devices due to its ease of molding and bonding as well as its transparency. Due to the softness of the PDMS material, however, it is challenging to use PDMS for building nanochannels. The channels tend to collapse easily during plasma bonding. In this paper, we present an evaporation-driven self-assembly method of silica colloidal nanoparticles to create nanofluidic junctions with sub-50 nm pores between two microchannels. The pore size as well as the surface charge of the nanofluidic junction is tunable simply by changing the colloidal silica bead size and surface functionalization outside of the assembled microfluidic device in a vial before the self-assembly process. Using the self-assembly of nanoparticles with a bead size of 300 nm, 500 nm, and 900 nm, it was possible to fabricate a porous membrane with a pore size of ~45 nm, ~75 nm and ~135 nm, respectively. Under electrical potential, this nanoporous membrane initiated ion concentration polarization (ICP) acting as a cation-selective membrane to concentrate DNA by ~1,700 times within 15 min. This non-lithographic nanofabrication process opens up a new opportunity to build a tunable nanofluidic junction for the study of nanoscale transport processes of ions and molecules inside a PDMS microfluidic chip.

We propose a simple self-assembly technique of silica colloidal nanoparticles to create a nanofluidic junction between two microchannels in polydimethylsiloxane (PDMS). Using this technique, a nanoporous bead membrane with a pore size down to ~45 nm was built inside a microchannel and applied to electrokinetic preconcentration of DNA samples.

通过胶体粒子自组装过程创建在PDMS微流控芯片分50纳米的纳米流体结

Polydimethylsiloxane (PDMS) is the prevailing building material to make microfluidic devices due to its ease of molding and bonding as well as its ...

工程学

Preparation of Light-responsive Membranes by a Combined Surface Grafting and Postmodification Process

In order to modify the surface tension of commercial available track-edged polymer membranes, a procedure of surface-initiated polymerization is presented. The polymerization from the membrane surface is induced by plasma treatment of the membrane, followed by reacting the membrane surface with a methanolic solution of 2-hydroxyethyl methacrylate (HEMA). Special attention is given to the process parameters for the plasma treatment prior to the polymerization on the surface. For example, the influence of the plasma-treatment on different types of membranes (e.g.&#160;polyester, polycarbonate, polyvinylidene fluoride) is studied. Furthermore, the time-dependent stability of the surface-grafted membranes is shown by contact angle measurements. When grafting poly(2-hydroxyethyl methacrylate) (PHEMA) in this way, the surface can be further modified by esterification of the alcohol moiety of the polymer with a carboxylic acid function of the desired substance. These reactions can therefore be used for the functionalization of the membrane surface. For example, the surface tension of the membrane can be changed or a desired functionality as the presented light-responsiveness can be inserted. This is demonstrated by reacting PHEMA with a carboxylic acid functionalized spirobenzopyran unit which leads to a light-responsive membrane. The choice of solvent plays a major role in the postmodification step and is discussed in more detail in this paper. The permeability measurements of such functionalized membranes are performed using a Franz cell with an external light source. By changing the wavelength of the light from the visible to the UV-range, a change of permeability of aqueous caffeine solutions is observed.

A plasma-induced polymerization procedure is described for the surface-initiated polymerization on polymer membranes. Further postmodification of the grafted polymer with photochromic substances is presented with a protocol of conducting permeability measurements of light-responsive membranes.

通过结合表面接枝和修改后的过程光敏感膜的制备

In order to modify the surface tension of commercial available track-edged polymer membranes, a procedure of surface-initiated polymerization is ...

生物工程

Electrophoretic Crystallization of Ultrathin High-performance Metal-organic Framework Membranes

We report the synthesis of thin, highly intergrown, polycrystalline metal-organic framework (MOF) membranes on a wide range of unmodified porous and non-porous supports (polymer, ceramic, metal, carbon, and graphene). We developed a novel crystallization technique, which is termed the ENACT approach: the electrophoretic nuclei assembly for the crystallization of highly intergrown thin films (ENACT). This approach allows for a high density of heterogeneous nucleation of MOFs on a chosen substrate via the electrophoretic deposition (EPD) directly from the precursor sol. The growth of well-packed MOF nuclei leads to a highly intergrown polycrystalline MOF film. We show that this simple approach can be used for the synthesis of thin, intergrown zeolite imidazole framework (ZIF)-7 and ZIF-8 films. The resulting 500 nm-thick ZIF-8 membranes show a considerably high H2 permeance (8.3 x 10-6 mol m-2 s-1 Pa-1) and ideal gas selectivities (7.3 for H2/CO2, 15.5 for H2/N2, 16.2 for H2/CH4, and 2655 for H2/C3H8). An attractive performance for C3H6/C3H8 separation is also achieved (a C3H6 permeance of 9.9 x 10-8 mol m-2 s-1 Pa-1 and a C3H6/C3H8 ideal selectivity of 31.6 at 25 &#176;C). Overall, the ENACT process, owing to its simplicity, can be extended to synthesize intergrown thin films of a wide range of nanoporous crystalline materials.

A simple, reproducible, and versatile approach for the synthesis of intergrown, polycrystalline metal-organic framework membranes on a wide range of unmodified porous and non-porous supports is presented.

超薄高性能金属-有机骨架膜的电泳结晶

We report the synthesis of thin, highly intergrown, polycrystalline metal-organic framework (MOF) membranes on a wide range of unmodified porous and ...

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.

聚合物薄膜在多孔基板上的转移程序,具有最小化的缺陷

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

Synthesis of Hydrogels with Antifouling Properties As Membranes for Water Purification

Hydrogels have been widely utilized to enhance the surface hydrophilicity of membranes for water purification, increasing the antifouling properties and thus achieving stable water permeability through membranes over time. Here, we report a facile method to prepare hydrogels based on zwitterions for membrane applications. Freestanding films can be prepared from sulfobetaine methacrylate (SBMA) with a crosslinker of poly(ethylene glycol) diacrylate (PEGDA) via photopolymerization. The hydrogels can also be prepared by impregnation into hydrophobic porous supports to enhance the mechanical strength. These films can be characterized by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) to determine the degree of conversion of the (meth)acrylate groups, using goniometers for hydrophilicity and differential scanning calorimetry (DSC) for polymer chain dynamics. We also report protocols to determine the water permeability in dead-end filtration systems and the effect of foulants (bovine serum albumin, BSA) on membrane performance.

This paper reports practical methods to prepare hydrogels in freestanding films and impregnated membranes and to characterize their physical properties, including water transport properties.

水凝胶的合成与防污性能作为膜的净水

Hydrogels have been widely utilized to enhance the surface hydrophilicity of membranes for water purification, increasing the antifouling properties and ...

聚合物接枝金属有机框架单层的自组装

Synthesis and Characterization of Self-Assembled Metal-Organic Framework Monolayers Using Polymer-Coated Particles

Metal-organic frameworks (MOFs) are materials with potential applications in fields such as gas adsorption and separation, catalysis, and biomedicine. Attempts to enhance the utility of MOFs have involved the preparation of various composites, including polymer-grafted MOFs. By directly grafting polymers to the external surface of MOFs, issues of incompatibility between polymers and MOFs can be overcome. Polymer brushes grafted from the surface of MOFs can serve to stabilize the MOF while enabling particle assembly into self-assembled metal-organic framework monolayers (SAMMs) via polymer-polymer interactions.
Control over the chemical composition and molecular weight of the grafted polymer can allow for tuning of the SAMM characteristics. In this work, instructions are provided on how to immobilize a chain transfer agent (CTA) onto the surface of the MOF UiO-66 (UiO = Universitetet i Oslo). The CTA&#160;serves as initiation sites for the growth of polymers. Once polymer chains are grown from the MOF surface, the formation of SAMMs is achieved through self-assembly at an air-water interface. The resulting SAMMs are characterized and shown to be freestanding by scanning electron microscopy imaging. The methods presented in this paper are expected to make the preparation of SAMMs more accessible to the research community and thereby expand their potential use as a&#160;MOF-polymer composite.

作者聚焦:探索自组装的 MOF-聚合物复合材料

A protocol for the synthesis and characterization of self-assembled metal-organic framework monolayers is provided using polymer-grafted, metal-organic framework (MOF) crystals. The procedure shows that polymer-grafted MOF particles can be self-assembled at an air-water interface resulting in well-formed, free-standing, monolayer structures as evidenced by scanning electron microscopy imaging.

使用聚合物包覆颗粒的自组装金属有机框架单层的合成和表征

Metal-organic frameworks (MOFs) are materials with potential applications in fields such as gas adsorption and separation, catalysis, and biomedicine. ...