Jinyou Lin

Nanoporous polystyrene fibers for oil spill cleanup

The development of oil sorbents with high sorption capacity, low cost, scalable fabrication, and high selectivity is of great significance for water environmental protection, especially for oil spillage on seawater. In this work, we report nanoporous polystyrene (PS) fibers prepared via a one-step electrospinning process used as oil sorbents for oil spill cleanup. The oleophilic-hydrophobic PS oil sorbent with highly porous structures shows a motor oil sorption capacity of 113.87 g/g, approximately 3-4 times that of natural sorbents and nonwoven polypropylene fibrous mats. Additionally, the sorbents also exhibit a relatively high sorption capacity for edible oils, such as bean oil (111.80 g/g) and sunflower seed oil (96.89 g/g). The oil sorption mechanism of the PS sorbent and the sorption kinetics were investigated. Our nanoporous material has great potential for use in wastewater treatment, oil accident remediation and environmental protection.

Facile control of intra-fiber porosity and inter-fiber voids in electrospun fibers for selective adsorption

We report a facile method to control intra-fiber porosity via varying the relative humidity and inter-fiber voids through the blending of two different polymeric fibers via multi-nozzles spinning of electrospun fibers for selective adsorption of oil from water.

Biomimicry via Electrospinning

Electrospinning, an efficient technique to produce long fibers with micro- or nanoscale diameters, has attracted tremendous interests during past decades. By orchestrating parameters in electrospinning, diverse forms of fibrous assemblies and individual fibers with hierarchical structures can be successfully achieved. Some of these versatile micro- and nanostructures display a remarkable resemblance to the materials and objects existing in nature, such as honeycomb, spider webs, extracellular matrix, plant tendril and leaf, etc. The emerging field of biomimicry enables one to mimic biology or nature to develop novel nanomaterials as well as to improve processes for materials via electrospinning. In this review, we present a full panorama of recent studies on biomimicry via electrospinning, and highlight some of biomimicked one-dimensional nanomaterials as well as their functions and applications to date.

Investigation of silica nanoparticle distribution in nanoporous polystyrene fibers

A number of fascinating properties of micro/nano-fibers can be obtained as their fine-structures are tuned. Here, we report a one-step procedure to construct nanoporous polystyrene (PS) fibers loaded with controllably distributed silica nanoparticlesvia tuning the solvent compositions in electrospinning. With decreasing solvent vapor pressure in electrospinning, the silica nanoparticles were clearly observed to be transferred from the interior of the PS fiber to its surface due to the phase separation of fluid jet in varying degrees. The silica nanoparticles embedded in the fibers exhibited porous cores contributing to an increase in Brunauer–Emmett–Teller surface area of the as-spun fibers. The presence of silica nanoparticles on the fiber surfaces enhanced the surface roughness with numerous papillae. Water droplets on a typical fiber surface readily sat on the apex of papillae because the air filled in these hierarchically roughened fibrous mats as a cushion, and therefore, displayed superhydrophobicity with a water contact angle of 156.7°. We believe that the exploitation of such a simple method for fine-controlling structures of micro/nano-fibers will endow these materials with new properties for some special applications such as in novel easy-cleaning coatings, microfluidic devices, and even smart membranes.

Nanoparticle decorated fibrous silica membranes exhibiting biomimetic superhydrophobicity and highly flexible properties

Inspired by the self-cleaning lotus leaf, here we report the fabrication of flexible fluorinated silica nanofibrous membranes with biomimetic non-wettable surfaces by electrospinning blend solutions of poly(vinyl alcohol) (PVA) and silica gel in the presence of silica nanoparticles, followed by calcination and fluoroalkylsilane (FAS) modification. The resultant silica nanofibers exhibited a lotus-leaf-like structure with numerous nanoparticles decorated on the fiber surfaces due to the rapid phase separation in electrospinning and calcination processing. The content of silica nanoparticles incorporated into the fibers proved to be the key factor affecting the fiber surface morphology and wettability. The fluorinated silica fibrous membranes containing 38.8 wt% silica nanoparticle showed the highest water contact angle (WCA) of 155°, oil contact angle (OCA) of 143°, orange juice contact angle (OJCA) of 142°, and milk contact angle (MCA) of 137°. Additionally, the fluorinated silica membranes exhibited good flexibility and the flexibility was also characterized by KES-FB2S. We believe that this new class of inorganic membranes is particularly promising for the development of high-temperature filtration, novel easy-clean coatings, and even flexible electronics.

One-step Electro-spinning/netting Technique for Controllably Preparing Polyurethane Nano-fiber/net

Electro-spinning/netting (ESN) as a cutting-edge technique evokes much interest because of its ability in the one-step preparation of versatile nano-fiber/net (NFN) membranes. Here, a controllable fabrication of polyurethane (PU) NFN membranes with attractive structures, consisting of common electrospun nanofibers and two-dimensional (2D) soap bubble-like structured nano-nets via an ESN process is reported. The unique nanoscaled NFN architecture can be finely controlled by regulating the solution properties and several ESN process parameters. The versatile PU nano-nets comprising interlinked nanowires with ultrathin diameters (5-40 nm) mean that the NFN structured membranes possess several excellent characteristics, such as an extremely large specific surface area, high porosity and large stacking density, which would be particularly useful for applications in ultrafiltration, special protective clothing, ultrasensitive sensors, catalyst support and so on.