Name: fabricating reactive surfaces with brush-like and crosslinked films of azlactone-functionalized block co-polymers
Uploaded: 2018-06-30T13:00:00.000+00:00
Duration: 10 min 9 s
Description: Watch this Scientific Journal Video about Fabricating Reactive Surfaces with Brush-like and Crosslinked Films of Azlactone-Functionalized Block Co-Polymers at JoVE.com

这项研究得到了堪萨斯州立大学的支持。这项研究的一部分是在纳米材料科学中心进行的, 这是由科学用户设施司、美国能源部、能源科学办公室主办的橡树岭国家实验室。

1. 飞碟乙PVDMA 合成20
<ol><li>飞碟宏链转移剂的合成 (宏 CTA)<ol>
<li>使用250毫升的圆底反应ﬂask 装有聚四氟乙烯涂层的磁力搅拌棒。</li>
		<li>将14.2 克甲基丙烯酸缩水甘油 (142.18 克/摩尔) 与490.8 毫克2氰基-2-丙基月桂 trithiocarbonate (CPDT) (346.63 克/摩尔) 相结合, 和87.7 毫克的 2,2′-偶 (4-甲氧基 24-二甲基 valeronitrile) (V-70) (308.43 克/摩尔) (摩尔比 CPDT: V-70 =5:1), 和苯 (100 毫升) 的空气自由圆底烧瓶。</li>
		<li>用氩气搅拌反应混合物30分钟。随后把溶液在温度控制的油浴在30°c 和反应 18 h。 注: 宏观 CTA 的靶分子量为1万克/摩尔. 18 小时被确定为达到合理转换所需的时间。聚合物溶液的颜色为透明浅黄色。</li>
		<li>18小时后, 将圆底烧瓶浸入液体 N2, 终止反应。</li>
		<li>将聚合物/苯 (~ 100 毫升) 的淡黄色溶液倒入400毫升己烷, 沉淀聚合物。</li>
		<li>搅拌混合物5分钟沉淀将在烧杯底部结算, 并通过过滤回收。</li>
		<li>在真空下一夜之间干燥沉淀。然后稀释400毫升的四氢呋喃 (THF)。在己烷中重新沉淀。</li>
		<li>用氩在一夜之间再干这个新沉淀。 注: 宏 CTA 是一种优良的黄色粉末。反应产物的产率将为43.8%。飞碟宏观 CTA 的 Mn是7990克/摩尔与多分散性 (PDI) 1.506 (MW = 12030 克/摩尔)。</li>
	</ol>
</li>
	<li>飞碟-bPVDMA 的合成<ol>
<li>在减压下, 将 VDMA 蒸馏, 并保留中间分数 (~ 70%) 供使用。 注: 这是去除聚合抑制剂所必需的。蒸馏装置附着在 Schlenk 线上, 空气密封阀部分打开至真空线。最小的热量使用 varistat 和加热地幔, 直到 VDMA 单体开始蒸馏超过每秒1滴率。</li>
		<li>将 2-乙烯基44二甲基 azlactone (VDMA) (139.15 克/摩尔) 单体 (10.436 克) 与飞碟 macroCTA (1.669 克) 相结合, V-70 (14.5 毫克; 飞碟-macroCTA: V-70 = 3:1) 和苯 (75.0 毫升) 在单颈部250毫升圆底反应中的摩尔比, ﬂask 配有聚四氟乙烯涂层磁力搅拌棒。 注: 分子量信息, PVDMA: 139.15 克/摩尔, 飞碟-macroCTA: 12030 克/摩尔, 苯: 78.11 克/摩尔。</li>
		<li>德加高纯度氩气搅拌30分钟, 然后放入油浴在32°c 为 18 h。</li>
		<li>通过将圆底烧瓶浸入液体 N2来终止反应。</li>
		<li>将聚合物沉淀三倍, 并在室温下在真空下干燥。</li>
		<li>根据 Lokitz等程序, 采用尺寸排除色谱法 (参见材料表), 对产品的分子量和质量进行了表征。20。尺寸排除色谱仪 (S) 配备三 PLgel 5 µm 混合 C 柱 (300 x 7.5 毫米) 系列, 一个折射率探测器 (波长 = 880 nm), 光电二极管阵列探测器, 多角度光散射 (加工) 探测器 (波长 = 660 nm), 和粘度计 (见材料表)。 注: 在本手稿中进行的所有实验都采用了飞碟和 PVDMA 块长度分别为56和175的产品。嵌段共聚物的分子量为37620克/摩尔, 而 PDI 为1.16。</li>
	</ol>
</li>
</ol>2. 在硅基板上生成派瑞林模具图案
<ol><li>派瑞林涂料<ol>
<li>油脂实验硅晶片在水中的 50%, 丙酮在5分钟后, 超声波在50% 的异丙醇 (IPA) 在水中5分钟。</li>
		<li>用去离子 (DI) 水冲洗硅片, 用氮气吹干。</li>
		<li>使用派瑞林涂布机在4英寸硅片上沉积 80 nm 和1µm 厚派瑞林 N (见材料表)。 注: 使用表面轮廓来表征派瑞林薄膜的厚度 (见材料表)。<ol>
<li>对每个派瑞林涂装系统进行派瑞林二聚体的派瑞林膜厚度标定。 注: 在目前的系统中, 需要80毫克和 ~ 1000 毫克派瑞林 N 二聚体分别获得 80 nm 和1µm 膜厚度 (根据所获得的校准曲线)。</li>
			<li>在派瑞林涂布机的操作过程中使用以下设置: 压力:80 mTorr, 持续时间: 1 小时, 炉膛温度: 690 °c, 蒸发器温度: 160 摄氏度。</li>
		</ol>
</li>
	</ol>
</li>
	<li>光刻<ol>
<li>在烤箱烘烤晶片在100°c 20 分钟;然后让晶片在室温下再坐3分钟。 注意: 额外的等待时间提高了光刻胶的附着力。</li>
		<li>添加2毫升的正光刻胶 (见材料表), 并免除在派瑞林涂层晶片的中心。自旋涂层的硅片在 3000 rpm 三十年代。 注: 自旋涂层必须在罩下完成。</li>
		<li>等待1分钟, 烘烤硅片上的热板在105°c 1 分钟。</li>
		<li>在掩码对准系统中加载光掩模 (参见材料表)。曝光硅片到紫外光 (λ = 325 毫微米) 为十年代以药量 65 mJ/cm2。</li>
		<li>让晶片在室温下再坐5分钟。</li>
		<li>通过淹没在开发者 (见材料表) 解决方案, 开发硅片2分钟. 用去离子水冲洗晶片, 然后用 N2干。在引擎盖下面做这个。 注意: 在开发后, 光刻胶似乎完全从暴露于紫外线的区域中移除。使用光学显微镜 (见材料表) 来验证晶片。</li>
	</ol>
</li>
	<li>反应离子蚀刻<ol>
<li>使用一种反应离子蚀刻工具 (见材料表) 用氧等离子体蚀刻已开发的晶片。</li>
		<li>应用氧流速为50厘米3/分钟在室压力 20 mTorr。</li>
		<li>对于派瑞林薄膜厚度为1µm, 使用 50 w 的射频功率和电感耦合等离子体 (ICP) 功率 500 W 的100s 是消除暴露派瑞林从图案的区域。这对应于派瑞林蚀刻率 1.0-1.15 µm/分钟。</li>
		<li>对于派瑞林厚度为80毫微米, 使用 50 w 的射频功率和 ICP 功率为 200 w, 五十五年代, 以消除被暴露的派瑞林从图案的区域。这对应于派瑞林蚀刻率570-620 毫微米/分钟。 注: 为了有效的派瑞林去除, 确定每一个被浸蚀系统的派瑞林蚀刻速率。</li>
		<li>用光学显微镜检查蚀刻衬底。在派瑞林完全从暴露的区域中移除后, 硅表面会出现发亮。</li>
		<li>使用曲面轮廓验证蚀刻深度 (请参阅材料表)。</li>
	</ol>
</li>
</ol>3. 派瑞林升降程序
<ol><li>高分子溶液的制备<ol>
<li>将飞碟 PVDMA溶于氯仿 (1%)。氯仿应无水, 以防止 azlactone 组的水解。 注: 氯仿是首选溶剂, 因为它具有较高的溶解度的聚合物, 允许更均匀的表面沉积的单一聚合物链相比, 其他有机溶剂25。</li>
	</ol>
</li>
	<li>清洁派瑞林钢板蜡纸与血浆清洁剂<ol>
<li>打开等离子清洗器 (见材料表) 的主电源, 并把派瑞林涂层的基底在等离子清洗室。</li>
		<li>打开真空泵, 将空气放在室内, 直到压力表小于 400 mTorr。</li>
		<li>稍微打开计量阀, 让空气进入等离子清洗器, 直到压力表显示 800-1000 mTorr。</li>
		<li>选择高模式 RF, 并暴露基体3分钟。</li>
		<li>在加工结束时, 关闭射频电源和真空泵。</li>
		<li>关闭等离子清洗器, 取出基板。 注: 在等离子清洗后, 表面显示亲水性行为 (图 1B)。等离子清洗前后裸硅表面的水接触角分别 27°2°和0°。</li>
	</ol>
</li>
	<li>飞碟-PVDMA、退火和超声波在派瑞林模具上的自旋涂层<ol>
<li>在十五年代使用自旋涂布机 (见材料表) 时,立即用100µL 1% 飞碟-PVDMA 在无水氯仿上自旋涂层。 注: 在1-2 吹打内进行自旋涂层聚合物溶液, 以尽量减少快速氯仿蒸发引起的薄膜不均匀性。</li>
		<li>在真空烘箱中, 将聚合物薄膜退火110摄氏度 (见材料表) 18 小时。 注: 退火允许聚合物相离析和表面附着的 GMA 块到表面26。<ol>
<li>退火后, 通过测量基体的接触角来表征聚合物涂层。曲面显示 75°±1°的接触角 (图 1C)20。</li>
		</ol>
</li>
		<li>油脂实验20毫升丙酮或氯仿中的基质, 去除派瑞林层和任何 physisorbed 聚合物。 注: 使用以下超声波条件: 超音波功率, 284 W;工作频率, 40 赫 (见材料表)。 注: 派瑞林还可以通过在承印物的边缘涂上一条透明胶片, 然后将胶带拉走27。</li>
		<li>将基底置于真空中, 干燥, 直到表征。</li>
	</ol>
</li>
</ol><img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/57562/57562fig1.jpg"> 图 1: 处理过的硅基板的接触角测量。(A)裸硅, (B)等离子清洗硅, (C)自旋涂层硅与飞碟-B-PVDMA (退火后和超声波的氯仿)。<a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/57562/57562fig1large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
4. 飞碟-PVDMA 界面定向装配程序
注: 本程序可在含有化学惰性背景 (4.1 节) 或生物惰性背景 (4.2 节) 的基板上执行, 具体取决于应用。
<ol><li>硅基材化学惰性背景的制备<ol>
<li>使用氧气等离子清洁剂清洁裸硅 (3.2 节)。</li>
		<li>吸管100µL 的氯 (1 小时, 1 小时, 2 小时, 2 h perfluorooctyl) 硅烷 (TPS) 到一个培养皿上, 并将硅基板置于真空干燥旁边的培养皿。</li>
		<li>将真空 (-750 乇) 用于化学气相沉积 (CVD) 1 小时。 注意: TPS 是剧毒的, CVD 过程应该在通风罩内进行。 注: 1 h 后, 基体显示疏水性行为。109°±3°的接触角通常是在 CVD 过程之后测量的。TPS 薄膜的厚度是 1.5, 0.5 纳米。 注: TPS 阻止活性表面氧化物与飞碟-PVDMA 的反应。</li>
		<li>用派瑞林 (1 µm 厚度) 涂上晶片。执行光刻和反应离子蚀刻产生派瑞林模式 (第2节) 和蚀刻离开 TPS 层在暴露的区域。</li>
	</ol>
</li>
	<li>在硅基板上制备聚乙二醇 (PEG) 背景。<ol>
<li>使用氧气等离子清洗剂3分钟清洁裸硅基板 (3.2 节)。</li>
		<li>对1小时的 TPS 进行 CVD (4.1.2 节)。</li>
		<li>将基质浸入 0.7% Pluronic F-127 的超纯水中, 在18小时内产生一个 PEG 层, 表面28,29。 注: Pluronic 在两个 PEG 链之间含有疏水性聚丙烯氧化物 (PPO) 聚合物块。在 PEG 链接触到溶液28时, PPO 块将聚合物锚定在 TPS 表面。</li>
		<li>用100毫升的超纯水冲洗和冲洗基体5分钟。</li>
		<li>用派瑞林涂布机在4寸硅片上沉积 80 nm 和1µm 厚派瑞林 N。</li>
		<li>执行光刻和反应离子蚀刻产生派瑞林模式 (第2节)。</li>
	</ol>
</li>
	<li>超声波、飞碟-硼PVDMA 聚合物的自旋涂层及基体退火<ol>
<li>油脂实验化学惰性 (TPS) 基板 (4.1 节) 或 PEG 功能基底 (4.2 节), 用于丙酮中的10分钟, 以去除派瑞林层。</li>
		<li>自旋涂层的微气泡基板与100µL 1% 飞碟 PVDMA 在无水氯仿在 1500 rpm 十五年代。</li>
		<li>在真空下将聚合物薄膜退火110摄氏度, 18 小时。</li>
		<li>油脂实验在丙酮或氯仿中的基质, 以10分钟去除表面上背景区域中的 physisorbed 聚合物。</li>
		<li>将基板存储在真空干燥中, 直到进一步使用。</li>
	</ol>
</li>
</ol>5. 定制飞碟-PVDMA 微接触印刷 (μCP)
<ol><li>制造<ol>
<li>根据标准的光刻工艺30制造硅大师。使用 CVD 工艺 (4.1.2 节) 将防粘 TPS 放到硅母版上。 注: 硅模具首次使用时应使用 TPS 处理, 并在使用5-10 次后重新应用。</li>
		<li>执行标准的软光刻方法制作邮票 (前体为固化剂质量比 10:1)31。 注: 本研究使用的邮票包括 micropillar 阵列 (直径 = 5-50 µm, 高度 = 20 µm)。</li>
		<li>剪掉一张邮票。在盐酸 (1 米), 丙酮5分钟内, 用乙醇 sonicating 10 分钟, 然后用5分钟来清洗。</li>
		<li>将在对流烤箱中的邮票干燥80摄氏度20分钟, 以去除残留的有机溶剂。</li>
	</ol>
</li>
	<li>微接触飞碟-硼PVDMA 在硅基板上的印刷<ol>
<li>使用 CVD 工艺 (4.1.2 节) 将 TPS 存入其表面。 注: TPS 层用于防止聚合物与图章表面的耦合。 注意: 在 TPS 吸附后, 接触角度测量可以用来表征邮票, 如图 2 (嵌入 A, B)所示。</li>
		<li>将飞碟-硼PVDMA 聚合物溶入无水氯仿中, 浓度为0.25-1%。</li>
		<li>将邮票浸入5毫升聚合物溶液中3分钟。</li>
		<li>等离子清洁 2×2 cm 裸硅基板3分钟清洁表面与飞碟块的耦合 (3.2 节)。</li>
		<li>从聚合物溶液中取出聚合物涂层的邮票。 注: 邮票必须用于打印, 而它们仍然是湿的, 并有一层的解决方案存在。</li>
		<li>在硅基板上直接放置墨印。</li>
		<li>使用手动钻床支架 (见材料表) (图 3) 将聚合物涂层的邮票按在硅表面上, 以促进图案的转移。在从聚合物溶液中取出包覆的邮票后, 立即将邮票应用于承印物 (1-2 秒以内)。 注: 在双面胶带的支持下, 无论是硅还是硅橡胶, 都可以将其放到最小, 以减少由于非均匀或高压冲压32而引起的双侧压印变形。</li>
		<li>在聚合物墨水和硅衬底之间应用保形接触1分钟. 使用估计压力75克/厘米2(7.35 帕) 按。</li>
		<li>轻轻地将邮票与硅表面隔开。</li>
		<li>在真空烤箱中立即将印刷的硅基板退火110摄氏度, 18 小时。</li>
		<li>油脂实验丙酮或氯仿中的印制硅基板, 以去除任何物理吸附的飞碟bPVDMA, 然后用 N2进行干燥。<ol>
<li>对超声波 (打印后的步骤) 和印制硅 (退火和步骤后) 进行表面特性分析, 以验证飞碟 PVDMA 的成功转移. 注: 表面轮廓和衰减的总反射率傅里叶变换红外光谱 (ATR-FTIR) 分析可以用来分析印刷硅基板和单片, 分别。</li>
		</ol>
</li>
		<li>将基底置于真空中, 干燥, 直到表征。</li>
	</ol>
</li>
</ol><img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/57562/57562fig2.jpg"> 图 2: 用 ATR-红外光谱测量法处理过的聚硅烷 (相对强度).(嵌入 A)接触角度测量裸的。(嵌入 B)TPS 处理后的接触角测量。<a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/57562/57562fig2large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/57562/57562fig3.jpg"> 图 3: 在硅基板上μCP 飞碟-b-PVDMA 溶液的设置.该程序包括使用(a)手动钻床, (B)一个 TPS 功能的飞碟 PVDMA 聚合物涂层, (C)等离子清洗2×2 cm 硅基板, (D)双面胶带。

作者没有什么可透露的。

本文提出了三种模式飞碟 PVDMA 的方法, 每个都有其优点和缺点。派瑞林升力法是一种通用的方法, 用于图形块共聚合体在微到纳米尺度的分辨率, 并已作为一个沉积面具在其他模式系统33,34,35。由于其表面附着力相对较弱, 在聚合物涂层后的溶剂中超声波可以很容易地从表面上去除派瑞林模具, 从而暴露出背景区域。背景?...

开发制造技术, 允许对化学和生物表面功能进行广泛和精确的控制, 对于各种应用, 从捕捉环境污染物到下一代的发展都是可取的。生物传感器, 植入物和组织工程设备1,2。功能高分子是通过 "嫁接" 或 "嫁接到" 技术3来调节表面性能的优良材料。这些方法允许控制的表面反应性的基础上的化学功能的单体和分子量的聚合物4,5,6。Azlactone 聚合物在这一背景下受到了强烈的研究, 因为 Azlactone 组在开环反应中有不同亲核试剂的快速耦合。这包括主要胺, 醇, 硫醇和肼组, 从而提供了一个多功能的路线进一步表面功能化7,8。Azlactone 聚合物薄膜已被应用于不同的环境和生物应用, 包括分析物捕获9,10, 细胞培养6,11, 和防污/防粘涂料12。在许多生物应用中, azlactone 聚合物薄膜在纳米到千分尺长度尺度上是可取的, 有利于空间控制分子呈现, 细胞相互作用, 或调节表面相互作用13, 14,15,16,17,18。因此, 应开发制造方法, 以提供高模式均匀性和良好的控制膜厚度, 而不损害化学功能19。
最近, Lokitz 开发了一种飞碟-b-PVDMA 嵌段共聚物, 能够操纵表面反应性。飞碟块对氧化-轴承表面, 产生高和可调谐的表面密度的 azlactone 组20。以前报告的模式, 这种聚合物的创建 biofunctional 接口使用传统的自上而下的光刻方法, 产生的非均匀聚合物薄膜的背景区域污染残留光刻胶材料, 造成高水平的非特异性化学和生物相互作用21、22、23。在这里, 试图钝化背景区域引起交叉反应与 azlactone 组, 损害聚合物反应性。考虑到这些限制, 我们最近开发了用于图案刷 (~ 90 nm) 或高度交联 (~ 1-10 微米) 的飞碟-PVDMA 薄膜的技术, 使其在化学或生物惰性的背景下完全保留化学聚合物的功能24。这些方法利用派瑞林升降、接口定向组装 (IDA) 和自定义微接触打印 (μCP) 技术。本文以书面和视频格式介绍了这些模式方法的高度详细的实验方法, 以及与每种技术相关的关键胶片特征和挑战和限制。

<table><tbody><tr><td>&lt;strong&gt;Material&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Ethanol, &amp;ge; 99.5%</td><td>Sigma-Aldrich</td><td>459844</td><td>-</td></tr><tr><td>HCL, 1.019 N in H2O</td><td>Fluka Analytical</td><td>318949</td><td>-</td></tr><tr><td>Acetone, &amp;ge; 99.5%</td><td>Sigma-Aldrich</td><td>320110</td><td>-</td></tr><tr><td>Benzene, &amp;ge; 99.9%</td><td>Sigma-Aldrich</td><td>270709</td><td>-</td></tr><tr><td>Isopropanol, ACS reagent, &amp;ge;99.5%</td><td>Sigma-Aldrich</td><td>190764</td><td></td></tr><tr><td>Hexane</td><td>Fisher Chemical</td><td>H292-4</td><td>-</td></tr><tr><td>Argon</td><td>Matheson Gas</td><td>G1901175</td><td>-</td></tr><tr><td>Tetrahydrofuran (THF), &amp;ge; 99.9%</td><td>Sigma-Aldrich</td><td>401757</td><td>-</td></tr><tr><td>Pluronic F-127</td><td>Sigma-Aldrich</td><td>P2443</td><td>-</td></tr><tr><td>Polydimethyl Siloxane (PDMS) Slygard 184</td><td>Dow Corning</td><td>4019862</td><td>-</td></tr><tr><td>Trichloro (1H,1H,2H,2H-perfluorooctyl) silane (TPS), 97%</td><td>Sigma-Aldrich</td><td>448931</td><td>It is toxic. Work with it under hood</td></tr><tr><td>Anhydrous Chloroform, &amp;ge; 99%</td><td>Sigma-Aldrich</td><td>372978</td><td>-</td></tr><tr><td>Positive Photoresist AZ1512</td><td>MicroChemicals</td><td>AZ 1512</td><td>amber-red liquid, density 1.083 g/cm3, spin coating step should be done under the hood</td></tr><tr><td>Developer AZ 300 MIF</td><td>MicroChemicals</td><td>AZ300 MIF</td><td>clear colourless liquid with slight amine odor and density of 1 g/cm3</td></tr><tr><td>1,2-Vinyl-4,4- dimethyl azlactone (VDMA)</td><td>Isochem North America, LLC</td><td>VDMA</td><td>-</td></tr><tr><td>2-cyano-2-propyl dodecyl trithiocarbonate (CPDT)</td><td>Sigma-Aldrich</td><td>723037</td><td>-</td></tr><tr><td>2,2&amp;prime;-Azobis (4methoxy-2,4-dimethyl valeronitrile) (V-70)</td><td>Wako Specialty Chemicals</td><td>CAS NO. 15545-97-8, EINECS No. 239-593-8</td><td>-</td></tr><tr><td>Parylene N</td><td>Specialty Coating Systems</td><td>15B10004</td><td>-</td></tr><tr><td>&lt;strong&gt;Name&lt;/strong&gt;</td><td>&lt;strong&gt;Company&lt;/strong&gt;</td><td>&lt;strong&gt;Catalog Number&lt;/strong&gt;</td><td>&lt;strong&gt;Comments&lt;/strong&gt;</td></tr><tr><td>&lt;strong&gt;Equipment&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Parylene Coater</td><td>Specialty Coating Systems</td><td>SCS Labcoater (PDS 2010)</td><td>-</td></tr><tr><td>Mask alignment system</td><td>Neutronix Quintel</td><td>NXQ8000</td><td>-</td></tr><tr><td>Oxygen Plasma Etcher</td><td>Oxford Instruments</td><td>Plasma Lab System 100</td><td>-</td></tr><tr><td>Surface Profilometer</td><td>Veeco</td><td>Dektak 150</td><td>Scan type was standard hill. Scan duration and force were 120 s and 1 mg, respectively.</td></tr><tr><td>Brightfield Upright Microscope</td><td>Olympus Corporation</td><td>BX51</td><td>-</td></tr><tr><td>Oxygen Plasma&amp;nbsp; Cleaner</td><td>Harrick Plasma</td><td>PDC-001-HP</td><td>-</td></tr><tr><td>Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR)</td><td>Perkin Elmer</td><td>ATR-FTIR 100</td><td>-</td></tr><tr><td>Atomic Force Microscopy (AFM)</td><td>PicoPlus</td><td>Picoplus atomic force microscope</td><td>Veeco MLCT-E cantilevers with a 0.5 N/m spring constant. Scan speeds varied between 0.25 and 1 Hz.</td></tr><tr><td>Scanning Electron Microscopy (SEM)</td><td>Hitachi Science Systems Ltd., Tokyo, Japan</td><td>-</td><td>-</td></tr><tr><td>Rotary Tool Workstation</td><td>Dremel</td><td>Model 220-01</td><td>-</td></tr><tr><td>Spin Coater</td><td>Smart Coater</td><td>SC100</td><td>-</td></tr><tr><td>Vacuum Oven</td><td>Yamato Scientific Co.</td><td>PCD-C6(5)000)</td><td>-</td></tr><tr><td>Size Exclusion Chromatography (SEC)</td><td>Waters Alliance 2695 Separations Module</td><td>720004547EN</td><td>-</td></tr><tr><td>Refractive Index (RI) detector</td><td>Waters</td><td>Model 2414</td><td>-</td></tr><tr><td>Photodiode Array Detector</td><td>Waters</td><td>Model 2996, 716001286</td><td>-</td></tr><tr><td>Multi-angle Light Scattering (MALS) Detector</td><td>Wyatt Technology</td><td>miniDAWN TREOS II</td><td>-</td></tr><tr><td>Viscometer</td><td>Wyatt Technology</td><td>Viscostar</td><td>-</td></tr><tr><td>PLgel 5 &amp;micro;m mixed-C columns (300 x 7.5 mm)</td><td>Agilent</td><td>5 &amp;micro;m mixed-C columns</td><td>-</td></tr><tr><td>Ellipsometer</td><td>J. A. Woollam</td><td>alpha-SE</td><td>Cauchy model, PGMA and PVDMA layers had refractive indices of 1.50 and 1.52 at 632 nm</td></tr><tr><td>Ultrasonic Sonicator</td><td>Fischer Scientific</td><td>FS-110H</td><td>-</td></tr></tbody></table>

fabricating reactive surfaces with brush-like and crosslinked films of azlactone-functionalized block co-polymers

本文介绍了利用 azlactone 基块共聚合物、聚 (甲基丙烯酸缩水甘油)-块状聚 (乙烯二甲基 azlactone) (飞碟bPVDMA) 生成新表面的制备方法。由于 azlactone 基团对胺、硫醇和羟基基团的高反应性, 飞碟-bPVDMA 表面可以通过二次分子进行修饰, 从而为各种应用创造化学或生物功能化界面。以前的飞碟-b-PVDMA 界面的报告使用了传统的自上而下的模式技术, 产生不均匀的薄膜和控制不善的背景化学。在这里, 我们描述了定制的模式技术, 使高均匀的飞碟bPVDMA 薄膜在化学惰性或具有分子的性质的背景下精确沉积。重要的是, 这些方法旨在以一种完全保留 azlactone 功能的方式, 通过每个处理步骤来存放飞碟-bPVDMA 薄膜。图案化的薄膜显示了与聚合物刷子 (90 nm) 或高度交联结构 (~ 1-10 微米) 相对应的良好控制厚度。画笔图案是使用派瑞林升力或接口定向装配方法生成的, 它对于通过调整飞碟-bPVDMA 模式密度或VDMA 块的长度。相比之下, 厚, 交联的飞碟-PVDMA 模式是通过定制的微接触印刷技术, 并提供了较高的加载或捕获二次材料由于较高的表面积, 体积比。讨论了各制造方法的详细实验步骤、关键胶片特征和故障排除指南。

接触角测量可用于评价硅与飞碟-PVDMA 的功能化。图 1描述了不同加工步骤中硅基板的接触角。等离子清洗硅基板的亲水性行为如图 1B所示。聚合物自旋涂层和退火后的接触角是 75° 1°(图 1C) , 它与 Lokitz等PVDMA 表面20所报告的值一致。
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Watch this Scientific Journal Video about Fabricating Reactive Surfaces with Brush-like and Crosslinked Films of Azlactone-Functionalized Block Co-Polymers at JoVE.com

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

报道了 azlactone 块共聚合物纳米厚刷或微米厚、交联膜的表面制备方法。讨论了关键的实验步骤、代表性结果和每个方法的局限性。这些方法对于创建具有定制物理特性和可调谐表面反应性的功能接口非常有用。

Azlactone 功能块共聚物的刷状和交联膜制备反应表面

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

fabricating-reactive-surfaces-with-brush-like-crosslinked-films

Universidad San Sebastian

Research

JoVE Journal

Engineering

8.2K 次观看.  Kansas State University. 报道了 azlactone 块共聚合物纳米厚刷或微米厚、交联膜的表面制备方法。讨论了关键的实验步骤、代表性结果和每个方法的局限性。这些方法对于创建具有定制物理特性和可调谐表面反应性的功能接口非常有用。

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

Synthesis of Programmable Main-chain Liquid-crystalline Elastomers Using a Two-stage Thiol-acrylate Reaction

This study presents a novel two-stage thiol-acrylate Michael addition-photopolymerization (TAMAP) reaction to prepare main-chain liquid-crystalline elastomers (LCEs) with facile control over network structure and programming of an aligned monodomain. Tailored LCE networks were synthesized using routine mixing of commercially available starting materials and pouring monomer solutions into molds to cure. An initial polydomain LCE network is formed via a self-limiting thiol-acrylate Michael-addition reaction. Strain-to-failure and glass transition behavior were investigated as a function of crosslinking monomer, pentaerythritol tetrakis(3-mercaptopropionate) (PETMP). An example non-stoichiometric system of 15 mol% PETMP thiol groups and an excess of 15 mol% acrylate groups was used to demonstrate the robust nature of the material. The LCE formed an aligned and transparent monodomain when stretched, with a maximum failure strain over 600%. Stretched LCE samples were able to demonstrate both stress-driven thermal actuation when held under a constant bias stress or the shape-memory effect when stretched and unloaded. A permanently programmed monodomain was achieved via a second-stage photopolymerization reaction of the excess acrylate groups when the sample was in the stretched state. LCE samples were photo-cured and programmed at 100%, 200%, 300%, and 400% strain, with all samples demonstrating over 90% shape fixity when unloaded. The magnitude of total stress-free actuation increased from 35% to 115% with increased programming strain. Overall, the two-stage TAMAP methodology is presented as a powerful tool to prepare main-chain LCE systems and explore structure-property-performance relationships in these fascinating stimuli-sensitive materials.

A novel methodology is presented to synthesize and program main-chain liquid-crystalline elastomers using commercially available starting monomers. A wide range of thermomechanical properties was tailored by adjusting the amount of crosslinker, while the actuation performance was dependent on the amount of applied strain during programming.

的可编程主链液晶性弹性体用双级硫醇丙烯酸酯反应合成

This study presents a novel two-stage thiol-acrylate Michael addition-photopolymerization (TAMAP) reaction to prepare main-chain liquid-crystalline ...

科研

化学

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 ...

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.

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.

任意基底上共轭聚合物薄膜的反应气相沉积

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

Fabricating Complex Culture Substrates Using Robotic Microcontact Printing (R-&#181;CP) and Sequential Nucleophilic Substitution

In tissue engineering, it is desirable to exhibit spatial control of tissue morphology and cell fate in culture on the micron scale. Culture substrates presenting grafted poly(ethylene glycol) (PEG) brushes can be used to achieve this task by creating microscale, non-fouling and cell adhesion resistant regions as well as regions where cells participate in biospecific interactions with covalently tethered ligands. To engineer complex tissues using such substrates, it will be necessary to sequentially pattern multiple PEG brushes functionalized to confer differential bioactivities and aligned in microscale orientations that mimic in vivo niches. Microcontact printing (&#956;CP) is a versatile technique to pattern such grafted PEG brushes, but manual &#956;CP cannot be performed with microscale precision. Thus, we combined advanced robotics with soft-lithography techniques and emerging surface chemistry reactions to develop a robotic microcontact printing (R-&#956;CP)-assisted method for fabricating culture substrates with complex, microscale, and highly ordered patterns of PEG brushes presenting orthogonal &#8216;click&#8217; chemistries. Here, we describe in detail the workflow to manufacture such substrates.

Fabricating Complex Culture Substrates Using Robotic Microcontact Printing R- &#181;CP and Sequential Nucleophilic Substitution

Cell culture substrates functionalized with microscale patterns of biological ligands have immense utility in the field of tissue engineering. Here, we demonstrate the versatile and automated manufacture of tissue culture substrates with multiple, micropatterned poly(ethylene glycol) brushes presenting orthogonal chemistries that enable spatially precise and site-specific immobilization of biological ligands.

制造复杂的栽培基质使用机器人微接触印刷（R-μCP）和顺序亲核取代

In tissue engineering, it is desirable to exhibit spatial control of tissue morphology and cell fate in culture on the micron scale. Culture substrates ...

生物工程

Multiscale Structures Aggregated by Imprinted Nanofibers for Functional Surfaces

Multiscale surface structures have attracted increasing interest owing to several potential applications in surface devices. However, an existing challenge in the field is the fabrication of hybrid micro-nano structures using a facile, cost-effective, and high-throughput method. To overcome these challenges, this paper proposes a protocol to fabricate multiscale structures using only an imprint process with an anodic aluminum oxide (AAO) filter and an evaporative self-aggregation process of nanofibers. Unlike previous attempts that have aimed to straighten nanofibers, we demonstrate a unique fabrication method for multiscale aggregated nanofibers with high aspect ratios. Furthermore, the surface morphology and wettability of these structures on various liquids were investigated to facilitate their use in multifunctional surfaces.

Presented is an easy method to fabricate nano-micro multiscale structures, for functional surfaces, by aggregating nanofibers fabricated using an anodic aluminum oxide filter.

功能表面用印迹纳米纤维聚合的多尺度结构

Multiscale surface structures have attracted increasing interest owing to several potential applications in surface devices. However, an existing ...

工程学

Preparation of Poly(pentafluorophenyl acrylate) Functionalized SiO2 Beads for Protein Purification

We demonstrate a simple method to prepare poly(pentafluorophenyl acrylate) (poly(PFPA)) grafted silica beads for antibody immobilization and subsequent immunoprecipitation (IP) application. The poly(PFPA) grafted surface is prepared via a simple two-step process. In the first step, 3-aminopropyltrimethoxysilane (APTMS) is deposited as a linker molecule onto the silica surface. In the second step, poly(PFPA) homopolymer, synthesized via the reversible addition and fragmentation chain transfer (RAFT) polymerization, is grafted to the linker molecule through the exchange reaction between the pentafluorophenyl (PFP) units on the polymer and the amine groups on APTMS. The deposition of APTMS and poly(PFPA) on the silica particles are confirmed by X-ray photoelectron spectroscopy (XPS), as well as monitored by the particle size change measured via dynamic light scattering (DLS). To improve the surface hydrophilicity of the beads, partial substitution of poly(PFPA) with amine-functionalized poly(ethylene glycol) (amino-PEG) is also performed. The PEG-substituted poly(PFPA) grafted silica beads are then immobilized with antibodies for IP application. For demonstration, an antibody against protein kinase RNA-activated (PKR) is employed, and IP efficiency is determined by Western blotting. The analysis results show that the antibody immobilized beads can indeed be used to enrich PKR while non-specific protein interactions are minimal.

Preparation of Polypentafluorophenyl acrylate Functionalized SiO2 Beads for Protein Purification

A protocol for the preparation of poly(pentafluorophenyl acrylate) (poly(PFPA)) grafted silica beads is presented. The poly(PFPA) functionalized surface is then immobilized with antibodies and used successfully for the protein separation through immunoprecipitation.

聚五氟丙烯酸酯 (五氟丙烯酸酯) 功能化 sio2 珠的蛋白质纯化

We demonstrate a simple method to prepare poly(pentafluorophenyl acrylate) (poly(PFPA)) grafted silica beads for antibody immobilization and subsequent ...

Fabricating Superhydrophobic Polymeric Materials for Biomedical Applications

Superhydrophobic materials, with surfaces possessing permanent or metastable non-wetted states, are of interest for a number of biomedical and industrial applications. Here we describe how electrospinning or electrospraying a polymer mixture containing a biodegradable, biocompatible aliphatic polyester (e.g., polycaprolactone and poly(lactide-co-glycolide)), as the major component, doped with a hydrophobic copolymer composed of the polyester and a stearate-modified poly(glycerol carbonate) affords a superhydrophobic biomaterial. The fabrication techniques of electrospinning or electrospraying provide the enhanced surface roughness and porosity on and within the fibers or the particles, respectively. The use of a low surface energy copolymer dopant that blends with the polyester and can be stably electrospun or electrosprayed affords these superhydrophobic materials. Important parameters such as fiber size, copolymer dopant composition and/or concentration, and their effects on wettability are discussed. This combination of polymer chemistry and process engineering affords a versatile approach to develop application-specific materials using scalable techniques, which are likely generalizable to a wider class of polymers for a variety of applications.

Two- and three-dimensional superhydrophobic polymeric materials are prepared by electrospinning or electrospraying biodegradable polymers blended with a lower surface energy polymer of similar composition.

制造超疏水高分子材料生物医学应用

Superhydrophobic materials, with surfaces possessing permanent or metastable non-wetted states, are of interest for a number of biomedical and industrial ...

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

The production of monodisperse cylindrical micelles is a significant challenge in polymer chemistry. Most cylindrical constructs formed from diblock copolymers are produced by one of three techniques: thin film rehydration, solvent switching or polymerization-induced self-assembly, and produce only flexible, polydisperse cylinders. Crystallization-driven self-assembly (CDSA) is a method which can produce cylinders with these properties, by stabilizing structures of a lower curvature due to the formation of a crystalline core. However, the living polymerization techniques by which most core-forming blocks are formed are not trivial processes and the CDSA process may yield unsatisfactory results if carried out incorrectly. Here, the synthesis of cylindrical nanoparticles from simple reagents is shown. The drying and purification of reagents prior to a ring-opening polymerization of &#949;-caprolactone catalyzed by diphenyl phosphate is described. This polymer is then chain extended by methyl methacrylate (MMA) followed by N,N-dimethyl acrylamide (DMA) using reversible addition&#8722;fragmentation chain-transfer (RAFT) polymerization, affording a triblock copolymer that can undergo CDSA in ethanol. The living CDSA process is outlined, the results of which yield cylindrical nanoparticles up to 500 nm in length and a length dispersity as low as 1.05. It is anticipated that these protocols will allow others to produce cylindrical nanostructures and elevate the field of CDSA in the future.

Crystallization-driven self-assembly (CDSA) displays the unique ability to fabricate cylindrical nanostructures of narrow length distributions. The organocatalyzed ring-opening polymerization of &#949;-caprolactone and subsequent chain extensions of methyl methacrylate and N,N-dimethyl acrylamide are demonstrated. A living CDSA protocol that produces monodisperse cylinders up to 500 nm in length is outlined.

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 ...

Preparation of Thermoresponsive Nanostructured Surfaces for Tissue Engineering

Thermoresponsive poly(N-isopropylacrylamide) (PIPAAm)-immobilized surfaces for controlling cell adhesion and detachment were fabricated by the Langmuir-Schaefer method. Amphiphilic block copolymers composed of polystyrene and PIPAAm (St-IPAAms) were synthesized by reversible addition-fragmentation chain transfer (RAFT) radical polymerization. A chloroform solution of St-IPAAm molecules was gently dropped into a Langmuir-trough apparatus, and both barriers of the apparatus were moved horizontally to compress the film to regulate its density. Then, the St-IPAAm Langmuir film was horizontally transferred onto a hydrophobically modified glass substrate by a surface-fixed device. Atomic force microscopy images clearly revealed nanoscale sea-island structures on the surface. The strength, rate, and quality of cell adhesion and detachment on the prepared surface were modulated by changes in temperature across the lower critical solution temperature range of PIPAAm molecules. In addition, a two-dimensional cell structure (cell sheet) was successfully recovered on the optimized surfaces. These unique PIPAAm surfaces may be useful for controlling the strength of cell adhesion and detachment.

Nanoscaled sea-island surfaces composed of thermoresponsive block copolymers were fabricated by the Langmuir-Schaefer method for controlling spontaneous cell adhesion and detachment. Both the preparation of the surface and the adhesion and detachment of cells on the surface were visualized.

温敏纳米结构表面的组织工程准备

Thermoresponsive poly(N-isopropylacrylamide) (PIPAAm)-immobilized surfaces for controlling cell adhesion and detachment were fabricated by the ...

Fabricating Degradable Thermoresponsive Hydrogels on Multiple Length Scales via Reactive Extrusion, Microfluidics, Self-assembly, and Electrospinning

While various smart materials have been explored for a variety of biomedical applications (e.g., drug delivery, tissue engineering, bioimaging, etc.), their ultimate clinical use has been hampered by the lack of biologically-relevant degradation observed for most smart materials. This is particularly true for temperature-responsive hydrogels, which are almost uniformly based on polymers that are functionally non-degradable (e.g., poly(N-isopropylacrylamide) (PNIPAM) or poly(oligoethylene glycol methacrylate) (POEGMA)). As such, to effectively translate the potential of thermoresponsive hydrogels to the challenges of remote-controlled or metabolism-regulated drug delivery, cell scaffolds with tunable cell-material interactions, theranostic materials with the potential for both imaging and drug delivery, and other such applications, a method is required to render the hydrogels (if not fully degradable) at least capable of renal clearance following the required lifetime of the material. To that end, this protocol describes the preparation of hydrolytically-degradable hydrazone-crosslinked hydrogels on multiple length scales based on the reaction between hydrazide and aldehyde-functionalized PNIPAM or POEGMA oligomers with molecular weights below the renal filtration limit. Specifically, methods to fabricate degradable thermoresponsive bulk hydrogels (using a double barrel syringe technique), hydrogel particles (on both the microscale through the use of a microfluidics platform facilitating simultaneous mixing and emulsification of the precursor polymers and the nanoscale through the use of a thermally-driven self-assembly and cross-linking method), and hydrogel nanofibers (using a reactive electrospinning strategy) are described. In each case, hydrogels with temperature-responsive properties similar to those achieved via conventional free radical cross-linking processes can be achieved, but the hydrazone cross-linked network can be degraded over time to re-form the oligomeric precursor polymers and enable clearance. As such, we anticipate these methods (which may be generically applied to any synthetic water-soluble polymer, not just smart materials) will enable easier translation of synthetic smart materials to clinical applications.

Protocols are described for the fabrication of degradable thermoresponsive hydrogels based on hydrazone cross-linking of polymeric oligomers on the bulk scale, microscale, and nanoscale, the latter for preparation of both gel nanoparticles and nanofibers.

通过反应挤出、微流体、自组装和电纺丝制备多长尺度可降解 Thermoresponsive 水凝胶

While various smart materials have been explored for a variety of biomedical applications (e.g., drug delivery, tissue engineering, bioimaging, etc.), ...