Bioinspired synthesis of optically and thermally responsive nanoporous membranes

Abstract

The development of porous membranes that can rapidly change flow rates in response to external, noninvasive stimuli has broad technological applications for areas ranging from biomedical devices to architecture. Environmentally responsive membranes have a fundamental role in the development of devices used in chemical sensors, biological sorters, sequencing, separations, high-throughput medical devices and labs on a chip. The design and engineering of these responsive porous membranes have been achieved through the coupling of porous membranes with polymeric materials that can change their physical conformation in response to pressure, heat, pH or different chemical entities. Inspired by the phototropic growth of coleoptiles and the light-mediated mechanism that plants use to open their stomata, in this work, light-responsive porous membranes were engineered, mathematically modeled and synthesized. This biologically inspired approach led to a state-of-the-art design technique and a device that outperforms its natural counterpart and is capable of reversibly controlling flow rates from 0.001 to 0.035 ml s À1 cm À2 in less than a few minutes using the noninvasive stimulus of light. We envision that the polymeric responsive membranes and the platform synthesis technique employed in this manuscript for their fabrication could be utilized in a broad range of applications and will have a great impact on the fields of fluid handling, biomedical high-throughput devices, sensors, medicine and other fields of chemistry, biology and mechanical engineering.

Bioinspired nanochannels based on polymeric membranes

“…In addition, the PET surface can be etched by high-concentration sodium hydroxide and generates carboxyl groups in situ, which can be used for further modification [79]. PET nanochannels can be used to manufacture various nanodevices in response to various stimuli, such as specific ions and molecules [25,66,[80][81][82][83][84][85][86], pH [65,67,68,[87][88][89][90], temperature [91,92], and multiple stimuli [11,56,60,[93][94][95] (Table 1). For example, inspired by the light/pH-switched The single conical-shaped PET nanochannel was prepared by a common method (Fig.…”

“…However, the lipid bilayer is fragile and sensitive, and it is difficult to artificially adjust working environment to biological systems. Inspired by biological nanochannels, researchers have developed artificial nanochannels functioning like the ion channel or nanopore in biological system membranes [1,6,7], called "bioinspired nanochannels" [8][9][10][11][12]. Bioinspired nanochannels have significant advantages over nanochannels embedded in lipid membranes: chemical and physical stability, flexibility in size and shape, and easy fabrication of high-density arrays [13,14].…”

Advances in polymeric membranes for water treatment

“…As a result of numerous advantages, wide areas of application, and high efficiency, bio-inspired membranes have the chance to be the next generation of membranes (Morones-Ramırez, 2013;Rawlings, Bramble, & Staniland, 2012). In this method, nature is considered a large database to which its scientific rules might be applied in engineering applications as efficient solutions for difficult problems.…”

Coupling Metallic Nanostructures to Thermally Responsive Polymers Allows the Development of Intelligent Responsive Membranes

“…Therefore, different composite membranes capable of changing their effective pore size with environmental triggers such as pH and ionic strength [3,4], temperature [5], and chemical moieties, such as glucose [6], have been developed. However, a recent interest has been the development of porous membranes responsive to light, since these present advantages potentially achieve rapid, remote, noninvasive, and localized flow control [7][8][9][10]. This work describes the development of a synthesis pathway to achieve grafting of optothermally responsive polymer-metal nanoparticle nanocomposites to polycarbonate track-etched porous membranes (PCTEPMs) to build an optothermally responsive porous membrane.…”