Name: synthesis of monodisperse cylindrical nanoparticles via crystallization-driven self-assembly of biodegradable block copolymers
Uploaded: 2019-06-20T15:00:00
Description: Watch this Scientific Journal Video about Synthesis of Monodisperse Cylindrical Nanoparticles via Crystallization-driven Self-assembly of Biodegradable Block Copolymers at JoVE.com

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1. 苯干
注:如果您可以使用干燥的溶剂塔,则通过五个冷冻泵-解冻循环收集苯和脱气。
<ol><li>在真空下250-300°C的250mL施伦克烧瓶中干燥3+分子筛,48小时,并转移到手套箱中。</li>
	<li>在烤箱中干燥两个安眠药,在150°C过夜,并将其转移到手套箱中。</li>
	<li>将激活的分子筛转移到两个安培中,然后从手套箱中取出。</li>
	<li>干燥双颈圆底烧瓶(RBF),并加入100 mL的苯,其体积最多等于安培?...

<ol>
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S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Giant+Wormlike+Rubber+Micelles.">Giant Wormlike Rubber Micelles.</a> Science. 283 (5404), 960-963 (1999).</li><li>Mai, Y., Eisenberg, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Self-assembly+of+block+copolymers.">Self-assembly of block copolymers.</a> Chemical Society Reviews. 41 (18), 5969-5985 (2012).</li><li>Charleux, B., Delaittre, G., Rieger, J., D&#8217;Agosto, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polymerization-Induced+Self-Assembly:+From+Soluble+Macromolecules+to+Block+Copolymer+Nano-Objects+in+One+Step.">Polymerization-Induced Self-Assembly: From Soluble Macromolecules to Block Copolymer Nano-Objects in One Step.</a> Macromolecules. 45 (17), 6753-6765 (2012).</li><li>Gilroy, J. B., 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=Monodisperse+cylindrical+micelles+by+crystallization-driven+living+self-assembly.">Monodisperse cylindrical micelles by crystallization-driven living self-assembly.</a> Nature Chemistry. 2, 566 (2010).</li><li>Boott, C. 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=Probing+the+Growth+Kinetics+for+the+Formation+of+Uniform+1D+Block+Copolymer+Nanoparticles+by+Living+Crystallization-Driven+Self-Assembly.">Probing the Growth Kinetics for the Formation of Uniform 1D Block Copolymer Nanoparticles by Living Crystallization-Driven Self-Assembly.</a> ACS Nano. 12 (9), 8920-8933 (2018).</li><li>G&#228;dt, T., Ieong, N. S., Cambridge, G., Winnik, M. 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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=Precision+Epitaxy+for+Aqueous+1D+and+2D+Poly(&#949;-caprolactone)+Assemblies.">Precision Epitaxy for Aqueous 1D and 2D Poly(&#949;-caprolactone) Assemblies.</a> Journal of the American Chemical Society. 139 (46), 16980-16985 (2017).</li><li>Sun, 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=Tuning+the+Size+of+Cylindrical+Micelles+from+Poly(l-lactide)-b-poly(acrylic+acid)+Diblock+Copolymers+Based+on+Crystallization-Driven+Self-Assembly.">Tuning the Size of Cylindrical Micelles from Poly(l-lactide)-b-poly(acrylic acid) Diblock Copolymers Based on Crystallization-Driven Self-Assembly.</a> Macromolecules. 46 (22), 9074-9082 (2013).</li><li>Fan, B., 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=Crystallization-driven+one-dimensional+self-assembly+of+polyethylene-b-poly(tert-butylacrylate)+diblock+copolymers+in+DMF:+effects+of+crystallization+temperature+and+the+corona-forming+block.">Crystallization-driven one-dimensional self-assembly of polyethylene-b-poly(tert-butylacrylate) diblock copolymers in DMF: effects of crystallization temperature and the corona-forming block.</a> Soft Matter. 12 (1), 67-76 (2016).</li><li>He, W. -. N., Zhou, B., Xu, J. -. T., Du, B. -. Y., Fan, Z. -. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two+Growth+Modes+of+Semicrystalline+Cylindrical+Poly(&#949;-caprolactone)-b-poly(ethylene+oxide)+Micelles.">Two Growth Modes of Semicrystalline Cylindrical Poly(&#949;-caprolactone)-b-poly(ethylene oxide) Micelles.</a> Macromolecules. 45 (24), 9768-9778 (2012).</li><li>Patra, S. 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=Cylindrical+Micelles+of+Controlled+Length+with+a+&#960;-Conjugated+Polythiophene+Core+via+Crystallization-Driven+Self-Assembly.">Cylindrical Micelles of Controlled Length with a &#960;-Conjugated Polythiophene Core via Crystallization-Driven Self-Assembly.</a> Journal of the American Chemical Society. 133 (23), 8842-8845 (2011).</li><li>Kynaston, E. L., Nazemi, A., MacFarlane, L. R., Whittell, G. R., Faul, C. F. J., Manners, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Uniform+Polyselenophene+Block+Copolymer+Fiberlike+Micelles+and+Block+Co-micelles+via+Living+Crystallization-Driven+Self-Assembly.">Uniform Polyselenophene Block Copolymer Fiberlike Micelles and Block Co-micelles via Living Crystallization-Driven Self-Assembly.</a> Macromolecules. 51 (3), 1002-1010 (2018).</li><li>Rizis, G., Mvan de Ven, T. G., Eisenberg, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Crystallinity-driven+morphological+ripening+processes+for+poly(ethylene+oxide)-block-polycaprolactone+micelles+in+water.">Crystallinity-driven morphological ripening processes for poly(ethylene oxide)-block-polycaprolactone micelles in water.</a> Soft Matter. 10 (16), 2825-2835 (2014).</li><li>Jin, X. -. 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=Long-range+exciton+transport+in+conjugated+polymer+nanofibers+prepared+by+seeded+growth.">Long-range exciton transport in conjugated polymer nanofibers prepared by seeded growth.</a> Science. 360 (6391), (2018).</li><li>Rizis, G., van&#8197;de&#8197;Ven, T. G. M., Eisenberg, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=&#8220;Raft&#8221;+Formation+by+Two-Dimensional+Self-Assembly+of+Block+Copolymer+Rod+Micelles+in+Aqueous+Solution.">&#8220;Raft&#8221; Formation by Two-Dimensional Self-Assembly of Block Copolymer Rod Micelles in Aqueous Solution.</a> Angewandte Chemie International Edition. 53 (34), 9000-9003 (2014).</li><li>Qiu, 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=Uniform+patchy+and+hollow+rectangular+platelet+micelles+from+crystallizable+polymer+blends.">Uniform patchy and hollow rectangular platelet micelles from crystallizable polymer blends.</a> Science. 352 (6286), 701 (2016).</li><li>Zhou, H., Lu, Y., Yu, Q., Manners, I., Winnik, M. 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三块共聚PCL 50-PMMA10-PDMA200的合成和活CDSA已经概述。尽管需要严格的条件,但 β-caprolactone 的环开聚合为聚合物提供了优异的特性,使 MMA 和 DMA 的链延伸得以成功。这些聚合物在自播种中取得了成功,获得了圆柱形云母的纯相,这些圆柱形云母被声波化成LN 98nm的种子颗粒中。通过简单添加单体,以受控方式生产平均长度可达 495 nm 的气缸。在这种情况下,在二块共聚?...

一维(1D)纳米结构,如圆柱体、纤维和管材,在各个领域越来越受到关注。其中,它们在聚合物科学中的受欢迎程度归功于其丰富的各种特性。例如,耿等人证明,与球形模型相比,微体细胞在啮齿类模型的血液中停留时间增加了十倍,Won等人发现聚丁二烯-b-聚类(环氧)纤维分散体显示,在风变测量1、2期间,当核心交联时,存储模量增加两个数量级。有趣的是,许多这些系统是通过块共聚物的自组装合成的,无论是通过更传统的溶剂转换和薄膜补液3方法,还是更先进的方法,如聚合诱导自组装和结晶驱动自组装(CDSA)4,5。每种技术都有其自身的优点,但是,只有 CDSA 才能产生具有均匀且可控长度分布的刚性颗粒。
Gilroy等人的开创性工作在六烷中形成了长多铁硅烷-b-聚二甲基硅氧烷(PFS-PDMS)气缸,使用温和的声波时,具有低轮廓长度分散度的极短圆柱体(Ln)。在普通溶剂中加入预定质量的二聚基共聚链后,合成了不同长度、Ln低至1.03的圆柱体。Manners小组的进一步工作强调了PFS系统的高度控制,该系统可用于形成极其复杂和等级的结构:块状协式云母、围巾形和哑铃云母,仅举几例。8.在这些演示之后,研究人员调查了CDSA的其他功能性系统,包括:半结晶商品聚合物(聚乙烯、聚丙酮、聚乳酸)9、10 ,11,12,13 和导电聚合物 (聚(3-六基硫磷), 聚苯乙烯) 14,15。配备这种可快速、高效地组装的二聚物共聚系统工具箱,研究人员近年来进行了更多的应用驱动型研究。 Jin等人在数百纳米的聚硫芬块共聚物中证明了兴奋扩散长度,我们小组展示了含有圆柱形结构的聚物(β-caprolactone)(PCL)的凝胶的形成。 17.
虽然这是一个强大的技术,CDSA确实有其局限性。块共聚物必须具有半结晶成分,以及低分散值和高端组保真度;低阶块污染物可能导致颗粒聚集或诱发形态变化18、19。由于这些限制,使用活聚合。然而,要获得具有上述特性的聚合物,需要大量的试剂净化、干燥程序和无水/无氧环境。已经尝试设计克服这一点的系统。例如,PFS块共聚物已经形成使用点击化学耦合聚合物链一起20。虽然生成的圆柱形纳米粒子具有示范性,但块共聚物通常通过准备尺寸排除色谱进行纯化,PFS的合成仍需要使用活的电子化聚合。我们小组最近实现了PCL的活CDSA,其成功围绕着使用活有机碱催化环开聚合(ROP)和可逆添加-碎片链转移(RAFT)聚合10。虽然这种方法更简单,但仍需要活的聚合。
随着该领域正朝着更多应用驱动的研究方向发展,并且由于与活聚合相关的问题,人们认为聚合物合成和自组装协议的大纲将有利于未来的科学工作。因此,在本手稿中,概述了PCL-b-PMMA-b-PDMA共聚物的完整合成和自组装。干燥技术将在β-caprolactone的有机化ROP的上下文中突出显示,并概述MMA和DMA随后的RAFT聚合。最后,将提出乙醇中这种聚合物的活CDSA方案,并批评由于实验技术落后而出现特征数据中的常见错误。

<table>
	<tbody>
		<tr>
			<td>2,2&#39;-azobisisobutyrnitrile</td>
			<td>Sigma Aldrich</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>250 mL ampoule</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>250 mL two neck RBF</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ampoule (25 mL)</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>B19 tap</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>B24 stopper</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Basic Alumina</td>
			<td>Fluka</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Buchner Flask</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Buchner Funnel</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Caclium Hydride</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Cannulae</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>caprolactone</td>
			<td>Arcos Organics</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Chain Transfer Agent</td>
			<td>Made in House</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Conical Flask (multiple sizes)</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Dessicator</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Diethyl Ether</td>
			<td>Merck</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Dioxane</td>
			<td>Fisher</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>diphenylphosphate</td>
			<td>Sigma Aldrich</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Distillation Condenser</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td>Fisher</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Filter Paper (multiple sizes)</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Gel Permeation Chrmoatography Instrument</td>
			<td>Agilent Technologies Infinity 1260 II</td>
			<td></td>
			<td>Running DMF at 50 &#176;C</td>
		</tr>
		<tr>
			<td>Glovebox</td>
			<td>Mbraun, Unilab</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Hotplate</td>
			<td>IKA, RCT basic</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Mercury Thermometer</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Methyl Methacrylate</td>
			<td>Sigma Aldrich</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Molecular seives</td>
			<td>Fisher</td>
			<td>MS/1030/53</td>
			<td></td>
		</tr>
		<tr>
			<td>N,N-dimethyl acrylamide</td>
			<td>Sigma Aldrich</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>NMR spectrometer</td>
			<td>Bruker 400 MHz</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphorus pentoxide</td>
			<td>Sigma Aldrich</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>RBF (multiple sizes)</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Schlenk Cap (B24)</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Schlenk Flask (250 mL)</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Schlenk Line</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Sonication Probe</td>
			<td>Bandelin Sonoplus</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Suba Seal (multiple sizes)</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>TEM grids</td>
			<td>EmResolutions, Formvar/carbon film 300 mesh copper</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>THF</td>
			<td>Merck</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>three neck adaptor</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Toluene</td>
			<td>Fisher</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Transmission Electron Microscope</td>
			<td>Jeol 2100</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

synthesis of monodisperse cylindrical nanoparticles via crystallization-driven self-assembly of biodegradable block copolymers

单分散圆柱形云母的生产是聚合物化学中的一大挑战。大多数由二块共聚物形成的圆柱形结构是由三种技术之一产生的:薄膜补液、溶剂切换或聚合诱导自组装,只生产柔性多分散圆柱体。结晶驱动自组装 (CDSA) 是一种方法,通过稳定低曲率结构,从而产生具有这些特性的圆柱体。然而,大多数核心形成块形成的活聚合技术不是微不足道的过程,CDSA过程如果执行不当,可能会产生不令人满意的结果。这里显示了从简单试剂中合成的圆柱形纳米粒子。介绍了在用磷酸二苯催化的β-卡洛尔酮的环开聚合之前试剂的干燥和纯化。然后,该聚合物通过甲基丙烯酸酯 (MMA) 延伸链,然后使用可逆添加-碎片链转移 (RAFT) 聚合,然后使用 N、N-二甲基丙烯酰胺 (DMA) 进行聚合,从而提供可进行 CDSA 的三块共聚物。乙醇。概述了活CDSA工艺,其结果产生长度达500nm的圆柱形纳米粒子,长度分散度低至1.05。预计这些协议将允许其他人在未来生产圆柱形纳米结构并提升CDSA领域。

PCL由1H NMR光谱和凝胶渗透色谱(GPC)进行分析。1H NMR 光谱产生 50 度的聚合 (DP), 与 3.36 ppm 和 4.08 ppm 的共振进行比较,分别对应于端组乙基质子和链内酯 β-质子(图 1b)。这提供了GPC获得的分子量值的验证,其中以10,800 g.mol-1(图1c)观察到的单个峰值,分散值为1.07。使用未正确干燥的试剂进行聚合产...

Watch this Scientific Journal Video about Synthesis of Monodisperse Cylindrical Nanoparticles via Crystallization-driven Self-assembly of Biodegradable Block Copolymers at JoVE.com

Synthesis of Monodisperse Cylindrical Nanoparticles via Crystallization-driven Self-assembly of Biodegradable Block Copolymers

结晶驱动自组装 (CDSA) 显示了制造窄长度分布的圆柱形纳米结构的独特能力。演示了β-卡罗酮的有机环开聚合以及甲基丙烯酸酯和N、N-二甲基丙烯酰胺的后续链延伸。概述了一种可生产长度达 500 nm 的单分散圆柱体的活 CDSA 协议。

通过结晶驱动生物降解块共聚物的自组装合成单分散圆柱状纳米粒子

The production of monodisperse cylindrical micelles is a significant challenge in polymer chemistry. Most cylindrical constructs formed from diblock ...

我们的协议侧重于环开和 RAFT 聚合，利用活体结晶驱动的自组装生产受控长度的块共聚合物油缸。环开和 RAFT 聚合的结合允许生产具有半晶体和功能区域的聚合物。这打开了 CDSA 字段，以向其他潜在应用程序开放。协议的成功解决了起始试剂的干燥性。干燥程序开始后，确保系统永远不会与大气接触。该方法需要掌握空气敏感化学技术的知识。我们相信，将这些实践引入视频形式将使研究人员能够自由地引入新想法，而不受缺乏实践经验的阻碍。首先，将所有玻璃器皿和搅拌棒转移到长凳上，在150摄氏度的烤箱中一夜干燥。将双颈 250 毫升圆底烧瓶夹在搅拌板上，并固定小脖子上的气密水龙头。在烧瓶中加入100毫升的埃西隆-卡波罗酮。通过一个脖子上的水龙头将圆底烧瓶连接到氮气管。在三 psi 的氮稳定流动下，通过主颈部将一克氢化钙加入烧瓶中。用玻璃塞子将第二个颈部安装，并在室温下在氮气下搅拌过夜。将烧瓶攻击到施伦克线，并打开氮气的稳定流动。将真空蒸馏设备组装在两个支架上，将埃西隆-卡波罗酮圆底烧瓶夹在一个支架上，将另一个圆底烧瓶夹到另一个支架上。保持氮气稳定通过系统，以防止水进入系统。将温度计插入静止头部，并将密封到位。将适配器连接到施伦克线路。关闭氮气流量，然后打开系统，通过此新连接到施伦克线进行真空吸尘。在60至80度的加热地衣中加热epsilon-caprolactone，将前五毫升收集在小圆底烧瓶中，其余在双颈圆底烧瓶中。将烧瓶放在液氮中，以有效地凝结瓶酮。为了加快工艺，将蒸馏设备用棉布和铝箔包裹。将施伦克线连接到双颈圆底烧瓶。将管路转动至真空 120 秒，将氮气转动 10 秒，共三次，以清除管路。打开管路和系统氮气。然后加入一克氢化钙，放入与塞子配合的收集瓶中，在氮气下搅拌过夜。同时，通过滴滴添加10毫升异丙醇，然后滴增加5毫升甲醇，处理多余的氢化钙。一旦冒泡停止，加入多余的水。用丙酮冲洗蒸馏设备，并放入烤箱过夜。在早上，再次重复真空蒸馏，而不添加氢化钙到单体一旦完成。然后打开烧瓶到氮气，开始通过管状体将胶囊转移到安培中。将安培转移到手套箱中。在手套箱中，准备库存解决方案。放入三个独立的小瓶中，加入0.011克羟基链转移剂，作为启动剂，0.01克二苯基磷酸盐，作为催化剂，和0.25克干单体，甲醇酮。在每个启动剂和催化剂小瓶中加入0.5毫升甲苯，轻轻搅拌，直到试剂溶解。然后将启动器和二苯磷酸盐库存溶液混合到一个小瓶中，并加入搅拌棒。将小瓶放在搅拌器上，调整速度以适度搅拌，并将单体溶液加入启动催化剂小瓶中。用盖子装上小瓶，在室温下搅拌八小时。然后从手套箱中取出小瓶，并立即使用巴斯德移液器将混合物滴入过量的冷二乙醚中，沉淀。通过布赫纳漏斗，过滤白色固体，在环境大气中干燥，并溶解在一毫升四氢黄。在二乙醚中沉淀两次以上，彻底干燥。首先在三毫升注射器中准备几个基本的氧化铝插头。将二恶烷和MMA过滤成单独的小瓶，以去除稳定剂。重量 0.5 克以前合成的 PCL，0.424 克 MMA，测量两毫升二恶烷到小瓶中，并允许溶解。准备一个纯 AIBN 库存溶液，每毫升 10 毫克，将移液器 139 微升放入反应混合物中。将混合物转移到装有搅拌棒的安培中，并密封。接下来将安培连接到施伦克线，并放入液氮中。溶液冻结后，将安培引入真空，直到真空计最多读取 10 次至负 1 毫巴。关闭安培，并允许完全解冻。再重复两次冷冻泵解冻循环。最后一个循环完成后，用氮气回填安培，并在65摄氏度的预热油浴中放入4小时。为了监测转化，从油浴中获取安培，在氮气流下切换超级密封盖，提取两滴，在小瓶中与600微升的脱氧氯仿混合，然后转移到核磁共振管中。将样品传输到 NMR 仪器的自动采样器以运行质子光谱。在稳定的氮气流下更换盖，并放回油浴中。现在，将油浴中加热的安培放入液氮中直到冷冻，然后在烟气罩中，将安培打开空气，将聚合淬火一分钟。接下来，滴将混合物加入大量冷二乙醚中，以沉淀。通过布赫纳过滤分离，并干燥。溶解聚合物和四氢黄，并沉淀两次以上。彻底干燥聚合物，用于质子 NMR 光谱和 SEC 分析。使用 0.5 克生成的 PCL-PMMA、1.406 克 DMA、2 毫升二恶烷和 111 微升（每毫升 AIBN 和二氧烷）重复此程序。在70摄氏度下加热聚合一小时，并在冷二乙醚中沉淀反应混合物三次。将产生的三块共糖体中五毫克放入小瓶中，加入一毫升乙醇。用盖子和副膜密封小瓶。70摄氏度的高温和加热3小时。之后，将小瓶拿出来慢慢冷却至室温。将溶液留在室温下老化两周。溶液变成多云，在完全组装时在底部形成一个独特的层。在防声波管中用乙醇稀释分散到每毫升一毫克。将管子放在冰浴中。将声波探针的尖端插入分散的中间区域。以最低强度对溶液进行 15 个周期的 2 分钟，允许两个周期之间冷却 15 分钟。以声波种子分散的一等同，用管子中的乙醇稀释至每毫升0.18毫克。然后，准备一个溶液的单体和四氢黄，浓度为25毫克每毫升。将 32.8 微升的单升溶液加入稀释的种子分散中，轻轻摇动，允许完全溶解。离开分散到年龄三天，盖子稍微开盖，这样四氢化物就可以蒸发。这将产生90纳米开始种子到500纳米的圆柱体。环开聚合的epsilon-caprolactone导致50度的聚合，由质子NMRI光谱在3.36 PPM的终点组乙基质子的共振和4.08 PPM的末端链酯α质子的共振决定。GPC 微量显示了具有单个峰值的典型分子量分布，其分散度值为 1.07，数平均分子量为 10，800 克/摩尔。相比之下，反应了12个小时的聚合使分子量高，每摩尔15，500克。使用未正确干燥的试剂，产生分子量较低的产品混合物。连续的 RAFT 聚合实现了 PMMA 块的 10 度聚合，GPC 微量中的单模峰。然而，当故意采取过高的转化大于70%，分子量和高分子量的肩膀观察到扩大。PDMA最终块的聚合程度为200，比较了PCL端链乙醚质子的4.08 PPM和2.93 PPM的DMA侧链甲基质子。GPC 的痕迹是狭窄和单模式的。使用不纯PCL-PMMA重复链延伸后，出现了低分子量肩部。请记住，请花时间干燥系统，因为任何水的存在都可能导致卡罗酮的聚合失败。确保一切都是干燥的。圆柱体核心和日冕之间的缓冲区域可以使其他CDSA结构在水中稳定下来，为研究和合作开辟新的途径。

Research

JoVE Journal

Chemistry

Origami Inspired Self-assembly of Patterned and Reconfigurable Particles

折纸灵感的图案和可重构颗粒自组装

There are numerous techniques such as photolithography, electron-beam lithography and soft-lithography that can be used to precisely pattern two ...

科研

化学

Formation of Ordered Biomolecular Structures by the Self-assembly of Short Peptides

生物分子有序结构由短肽的自组装形成

In nature, complex functional structures are formed by the self-assembly of biomolecules under mild conditions. Understanding the forces that control ...

Self-assembly of Complex Two-dimensional Shapes from Single-stranded DNA Tiles

复杂的二维形状的从单链DNA的瓷砖自组装

Current methods in DNA nano-architecture have successfully engineered a variety of 2D and 3D structures using principles of self-assembly. In this ...

Functionalization of Single-walled Carbon Nanotubes with Thermo-reversible Block Copolymers and Characterization by Small-angle Neutron Scattering

单壁碳纳米管与热可逆嵌段共聚物及表征功能化小角度中子散射

We demonstrate a protocol for single-walled carbon nanotube functionalization using thermo-sensitive PEO-PPO-PEO triblock copolymers in an aqueous ...

Synthesis of Ligand-free CdS Nanoparticles within a Sulfur Copolymer Matrix

a硫磺共聚物基质内的免费配体硫化镉纳米粒子的合成

Aliphatic ligands are typically used during the synthesis of nanoparticles to help mediate their growth in addition to operating as high-temperature ...

Synthesis of Protein Bioconjugates via Cysteine-maleimide Chemistry

Synthesis of Protein Bioconjugates via Cysteine-maleimide Chemistry

蛋白质生物缀合物的合成<em&gt;通过</em&gt;半胱氨酸马来酰亚胺化学

The chemical linking or bioconjugation of proteins to fluorescent dyes, drugs, polymers and other proteins has a broad range of applications, such as the ...

Liquid-cell Transmission Electron Microscopy for Tracking Self-assembly of Nanoparticles

用于跟踪纳米粒子自组装的液体细胞透射电子显微镜

Drying a nanoparticle dispersion is a versatile way to create self-assembled structures of nanoparticles, but the mechanism of this process is not fully ...

Synthesis of a Thiol Building Block for the Crystallization of a Semiconducting Gyroidal Metal-sulfur Framework

半导体回转金属硫框架结晶的硫醇构建块的合成

We present a method for preparing thioester molecules as the masked form of the thiol linkers and their utilization for accessing a semiconducting and ...

Synthesis of Substrate-Bound Au Nanowires Via an Active Surface Growth Mechanism

通过活性表面生长机制合成基片束缚金纳米线

Advancing synthetic capabilities is important for the development of nanoscience and nanotechnology. The synthesis of nanowires has always been a ...

Synthesis of Bimetallic Pt/Sn-based Nanoparticles in Ionic Liquids

离子液体中双金属 Pt/锡基纳米粒子的合成

We demonstrate a method for the synthesis of bimetallic nanoparticles consisting of Pt and Sn. A synthesis strategy is used in which the particular ...