Feilong Zhang's Research

Feilong Zhang

Repairable cascaded slide-lock system

1. FeilongZhang, LeiJiang and Shutao Wang*. Repairable cascaded slide-lock system endows bird feathers with tear-resistance and superdurability. PNAS 111, 10046-10051 (2018) .

Bird feathers have aroused tremendous attention for their super-durability against tears during long flights through wind and even bushes. Although feathers may inevitably be unzipped, the separated feather vanes can be repaired easily by bill stroking. However, the mechanism underlying bird feathers’ superdurability against tears remains unclear. Here, we reveal that the superdurability of bird feathers arises from their repairable cascaded slide- lock system, which is composed of hooklets, a slide rail, and spines at the end of the slide rail as terminating structures. Microscopy with a micronano manipulating system and 3D X-ray microscopy provided high- level visibility into the 3D fine structures and the entire unzipping process of feathers. The hooklets can slide along the slide rail reversibly when suffering external forces, and the sliding hooklet can be locked by the spine at the ends of barbules when larger pulling forces are applied and even slide farther away due to the unzipping of the interlocking structure with large deformation of the barbules. The elongation before separation of adjacent barbs can reach up to 270%, and the separation force can be maintained above 80% of the initial value even after 1,000 cycles of separating and repairing. These results prove that the cascaded slide-lock system ensures the superdurability of bird feathers against tears.

Circulating Tumour Cells Capture

1.Feilong Zhang, Yan Jiang, XueliLiu, Jingxin Meng, Pengchao Zhang, Hongliang Liu, Gao Yang, Guannan Li, LeiJiang, Li-Jun Wan, Jin-Song Hu & Shutao Wang. Hierarchical Nanowire Arraysas Three-Dimensional Fractal Nanobiointerfaces for High Efficient Capture ofCancer Cells. Nano Lett. 16, 766-772, (2016).
A hierarchical assembled ITO nanowire array with both horizontal and vertical nanowire branches was fabricated as a new three-dimensional fractal nanobiointerface for efficient cancer cell capture. Comparing with ITO nanowire array without branches, this fractal nanobiointerface exhibited much higher efficiency (89% vs 67%) and specificity in capturing cancer cells and took shorter time (35 vs 45 min) to reach the maximal capture efficiency. As indicated by the immunofluorescent and ESEM images, this enhancement can be attributed to the improvement of topographical interaction between cells and the substrate. The introduction of horizontal and vertical nanowire branches makes the substrate topographically match better with cell filopodia and provides more binding sites for cell capture. The live/dead cell staining and proliferation experiments confirm that this fractal nanobiointerface displays excellent cyto-compatibility with an over 96% cell viability after capture. These results provide new insights and may open up opportunities in designing and engineering new cell-material interfaces for advanced biomedical applications.

Binary Cooperative Polymers

1. FeilongZhang, Junbing Fan, Pengchao Zhang, Mingjie Liu, Jingxin Meng, LeiJiang and Shutao Wang*. A monolithic hydro/organo macro copolymer actuator synthesized via interfacial copolymerization. NPG Asia Mater. 2017, 9, e380, DOI: 10.1038/am.2017.61.

Syntheticpolymer actuators have aroused tremendous attention for their potentialapplications in artificial muscle, soft robotic and sensor. Most previousefforts have been focused on smart hydrogels with bilayer structures, which canchange their shape in response to environmental stimuli, such as temperature,light and certain chemicals. However, hydrogel are limited to low modulus andweak mechanical strength which definitely hinders its practical application.Here, we synthesized a robust monolithic actuator of macro-scalehydro/organo binary cooperative Janus copolymer film, directlyby one-step interfacial polymerizationof immiscible hydrophilic and hydrophobic vinyl monomer solutions, exhibitingbinary cooperative shape transformation to multiple external stimuli. Morefascinating, the Janus copolymer film is able to work in boththe aqueous solutions and organic solvents, with bidirectional andsite-specific bending arising from cooperative asymmetric swelling/shrinking ofthe hydro and organo networks. In addition, the as-preparedJanus copolymer film can act as sensor elementsfor solvent leakage warning. This binary cooperative strategy is applicable tomost of immiscible monomer systems and provides ageneral approach in developing novel functional copolymer materials.

Flexible Dry Hydrogel with Lamella-Like Structure

1. Feilong Zhang, Jiajia Zhou, Zhen Gu, Man Yang, SihengLi, YongyangSong, Jun-Bing Fan, JingxinMeng, Peiyi Wu, Lei Jiang & Shutao Wang*. Flexible Dry Hydrogel withLamella-Like StructureEngineeredvia Dehydrationin Poor Solvent. CCS Chem. 2019, 1, 533–543. DOI:10.31635/ccschem.019.20190007.

Hydrogels are among the most promising biologicmaterials inrecent technology with numerous desired applications, including serving asbiosensors,drug deliveryvehicles, and tissue-engineered products for cell matrices. However, they oftendehydrate, and become stiff and brittle in air, causing lossof flexibilityand functions. Several layered structureshave beenproven to increase the strength, toughness, and even flexibility of thesematerials, whichmight providea new clue for the sustenance of the flexibility ofdrying gels. Herein, we report a novel solvent-dehydrated hydrogelengineering approach,aimed tochange the inner structure and keep the flexibility of adehydrated hydrogel in the air viasolvent-induced dehydration,for example, acetone-dehydratedpolyacrylicacid hydrogel. This flexibledry gelcould be folded, twisted, and stretched without any damage due to the assumed lamella-likestructures,contrary to dry gels without these microstructures or those with porousstructures, whichretain brittleconsistency. The flexible dry gel also exhibited excellentself-healing capability with theassistance ofsolvents. Fascinatingly, this flexiblegel filmdisplayed strain-visualizing paper writing/erasing performance properties, with water actingasinvisible ink.Thus, this fabricated flexible hydrogelfilm mightfunction as confidential information storage material. Our current approach isversatile, henceapplicable toother hydrogels, and provides insightinto theengineering of other functional gels for extended future applications.

Bioinspired self-cleaning coating

1. Chuqian Wang, Feilong Zhang*, Cunming Yu, and Shutao Wang. Durable Underwater Superoleophobic Coatings via Dispersed Micro Particle-Induced Hierarchical Structures Inspired by Pomfret Skin. ACS Appl. Mater. Interfaces 2020, 12, 42430−42436.

Underwater superoleophobic materials due to its excellent antioil and self-cleaning performance have attracted tremendous attention. Current underwater superoleophobic surfaces usually use complex methods to construct the surface structure limiting the yield and not suitable for largescale production. Here, inspired by the superoleophobicity of pomfret skin, we developed a strategy to fabricate superoleophobic coatings with hierarchical micro/nano structures by doping hydrophilic micro silica particle in calcium alginate hydrogel. The introduction of micro particles significantly reduces the adhesion of oil and improves the mechanical properties of the coatings. The prepared coatings also survived in high temperature and high salinity environment and the dried for free-standing films. The free-standing dry coating films can be used like wallpaper to decorate the targeted surface and endow them with underwater superoleophobicity. We expect that this work will provide a new method for designing underwater superoleophobic coatings and the wallpaper-like coating films allow largescale production and will also promote the commercialization of oil-repellent materials.