Dendukuri Dhananjay, Pregibon Daniel C, Collins Jesse, Hatton T Alan, Doyle Patrick S
Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Nat Mater. 2006 May;5(5):365-9. doi: 10.1038/nmat1617. Epub 2006 Apr 9.
Precisely shaped polymeric particles and structures are widely used for applications in photonic materials, MEMS, biomaterials and self-assembly. Current approaches for particle synthesis are either batch processes or flow-through microfluidic schemes that are based on two-phase systems, limiting the throughput, shape and functionality of the particles. We report a one-phase method that combines the advantages of microscope projection photolithography and microfluidics to continuously form morphologically complex or multifunctional particles down to the colloidal length scale. Exploiting the inhibition of free-radical polymerization near PDMS surfaces, we are able to repeatedly pattern and flow rows of particles in less than 0.1 s, affording a throughput of near 100 particles per second using the simplest of device designs. Polymerization was also carried out across laminar, co-flowing streams to generate Janus particles containing different chemistries, whose relative proportions could be easily tuned. This new high-throughput technique offers unprecedented control over particle size, shape and anisotropy.
精确成型的聚合物颗粒和结构被广泛应用于光子材料、微机电系统、生物材料和自组装等领域。目前颗粒合成的方法要么是间歇过程，要么是基于两相系统的流通式微流体方案，这限制了颗粒的产量、形状和功能。我们报道了一种单相方法，该方法结合了显微镜投影光刻和微流体技术的优点，能够连续形成形态复杂或多功能的颗粒，直至胶体长度尺度。利用聚二甲基硅氧烷（PDMS）表面附近自由基聚合的抑制作用，我们能够在不到0.1秒的时间内重复图案化并使颗粒排成行流动，使用最简单的设备设计即可实现每秒近100个颗粒的产量。聚合反应也在层流、并流的流股中进行，以生成含有不同化学组成的Janus颗粒，其相对比例可以很容易地调节。这种新的高通量技术为颗粒尺寸、形状和各向异性提供了前所未有的控制。
