The rapid development of modern technology has put forward higher requirements on thermal insulation materials in many fields. Due to the inevitable defects of common insulation materials, a novel super-insulation material with high performance should be explored. In this article, a flexible, sandwiched super-insulation polyimide (PI) fabric has been designed and fabricated by using an electrohydrodynamic jet technology simply. This unique sandwiched fabric possessed an ultra-low thermal conductivity (16.7 mW m−1 K−1), excellent mechanical properties and a wide operating temperature range. Furthermore, it still has some other multifunctions, such as great cryogenic resistance, self-extinction and thermal stability. Such a sandwiched PI fabric with remarkable integrated performance will have potential engineering applications under harsh conditions, such as the aerospace field.

Superhydrophobic self-cleaning materials are widely applicable in many areas, but the low durability of superhydrophobicity is always a major obstacle for real-world applications. Here we propose a rather simple way to increase durability. We combine electrospinning and polyimides with nano-sized silica to create a durable self-cleaning film. Such films present strong resistance to heat and abrasion, along with thermal insulation. The delicate lotus effect can also be tough and durable.

With the increasing awareness of environmental protection, it is imperative to develop advanced materials that can clean up spilled oil and organic contaminants efficiently. Herein, we designed and fabricated a series of novel polyimide (PI) aerogels by freeze-drying. The PI aerogels exhibit excellent absorption capability. The toluene absorption capability even ranked first among reported organic absorbents. The PI aerogels also exhibit good absorption recyclability. Surprisingly, the PI aerogels show high flexibility in liquid nitrogen, and liquid nitrogen absorbed by PI aerogels can be squeezed out repeatedly as if it were water in a sponge. What is more, PI aerogels are also usable as sorbents at high temperature and in harsh acid. These desirable attributes would enable PI aerogels to act as ideal sorbents in extreme environments. Together with thermal insulation and fire-resistance, the multifunctional, marvelous PI aerogels are expected to further extend their practical applications.

Inspired by dusty spider dragline silk, we studied the adhesive interaction between artificial nanofibers and their aerosol surroundings. The nanofibers are found to be able to actively capture particulate matters from the environment, exactly as the spider dragline silk does. Examinations prove that such nanofibrous adhesion is insensitive to the chemical nature of the fibers and the physical states of the particulate matter and depends only on the fiber diameters. Such facts indicate that nanofibrous adhesion is a case of dry adhesion, mainly governed by van der Waals force, sharing the same mechanism to gecko adhesion. Nanofibrous adhesion is of great importance and has promising potential. For instance, in this work, nanofibers are fabricated into a thin and translucent filter, which has a filtration performance, as high as 95%, that easily outperformed ordinary ones. We believe that this adhesive property of nanofibers will open up broader applications in both scientific and industrial fields.Keywords: adhesion; dry adhesion; fine particulate matters; polymeric nanofibers;

The fabrication of hydrogels with excellent self-healing properties and high mechanical strength has become a challenging and fascinating topic. The aim of this study is to fabricate a novel robust PAS hydrogel with self-healing properties. The self-healing mechanism and possible interactions between PAS chains of the hydrogel are proposed.

The water strider is a wonderful case that we can learn from nature to understand how to stride on the water surface. Inspired by the unique hierarchical micro/nanostructure of the water strider leg, in this article, we designed and fabricated an artificial strider leg with refined nanogroove structure by using an electrospinning and sacrificial template method. A model water strider that was equipped with four artificial legs showed remarkable water-repellent performance; namely, it could carry a load that was about 7 times heavier than its own weight. Characterization demonstrated that, even though the artificial leg did not possess a superhydrophobic surface, the numerous nanogrooves could still provide a huge supporting force for the man-made model strider. This work enlightens the development of artificial water-walking devices for exploring and monitoring the surface of water. Because of the advances of the applied materials, the devices may fulfill tasks in a harsh aquatic environment.Keywords: biomimetic; electrospinning; nanogroove surface; water strider leg; water-repellent performance

Superhydrophobic surface with high solid/liquid adhesion is of great fundamental and technological importance. However, the fabrication of adhesive superhydrophobic polymer surfaces with high stability is rare, which limits the utilization of such surfaces in harsh environments. This paper illustrates a simple electrospinning way to produce fluorinated polyimide nanofibric mat with adhesive superhydrophobicity as well as high thermal stability. The water contact angle on the mat reaches as high as 157.8° and the adhesive force to a water drop is up to 98.3 μN. Moreover, the adhesive superhydrophobic polyimide mat is able to stand extreme heat up to 300 °C. By virtue of the facile electrospinning technique, large-area flexible mats can be easily achieved. Such an electrospun fluorinated polyimide mat will possess broader applications than ordinary organic superhydrophobic surfaces owing to its excellent stability in harsh environments.

Fumed silica/bisphenol A dicyanate ester (BADCy) nanocomposites were prepared by introducing different contents of nano-sized fumed SiO2 into the BADCy matrix. Two different average primary particle diameters of 12 and 40 nm were chosen. Dibutyltindilaurate (DBTDL) catalyst was chosen to catalyze the cyanate ester group into triazine group via cyclotrimerization reaction. The SEM micrographs indicated that the fumed SiO2 particles were homogeneously dispersed in the poly(bisphenol A dicyanate) matrix by means of ultrasonic treatment and the addition of a coupling agent. The FTIR spectroscopy shows that, not only DBTDL catalyzes the polymerization reaction but also -OH groups of the SiO2 particles surface help the catalyst for the complete polymerization of BADCy monomer. The thermal stability of the cured BADCy can be improved by adequate addition of fumed SiO2. A slight increase in the dielectric constant and dielectric loss values were identified by testing the dielectric properties of the prepared nanocomposite samples. By increasing the SiO2 content, there was a slight increasing in the thermal conductivity values of the tested samples. The obtained results proved that the fumed silica/BADCy nanocomposites had good thermal and dielectrical properties and can be used in many applications such as in the thermal insulation field.

•The PI aerogels were prepared from PAS hydrogels via environment friendly method.•The HPI/F aerogels exhibit a highly efficient and recyclable adsorption capacity.•The work opens up the use of polymer hydrogels for the fabrication of 3D aerogels.Developing advanced absorbent materials with multifunctional properties has always been one of hotspots in the research. Here, multifunctional polyimide (PI) aerogels absorbents were prepared from poly(amic acid) ammonium salt (PAS) hydrogels via facile and environment friendly method. By tuning the micro- and nano-structures and surface modification with fluoroalkylsilane, the polyimide/fluoroalkylsilane (HPI/F) aerogels fabricated from hydrogels exhibit superhydrophobic and superoleophilic attributes. Moreover, the HPI/F aerogels show excellent mechanical flexibility, fire-resistance and high thermostability, which enable them to be a highly efficient and recyclable sorbent material useable at extremely high or low temperatures. They also exhibit chemical durability in strong acidic solutions. This work opens up the use of polymer hydrogels for the fabrication of 3D aerogel materials and shows the possibility for the application in diverse work conditions.Multifunctional polyimide (PI) aerogels absorbents were prepared from poly(amic acid) ammonium salt (PAS) hydrogels via facile and environment friendly method. By tuning the micro- and nano-structures and surface modification with fluoroalkylsilane, the polyimide/fluoroalkylsilane (HPI/F) aerogels fabricated from hydrogels exhibit a highly efficient and recyclable adsorption capacity useable at extremely high or low temperatures. They also exhibit chemical durability in strong acidic solutions. This work opens up the use of polymer hydrogels for the fabrication of 3D aerogel materials and shows the possibility for the application in diverse work conditions.

Superhydrophobic self-cleaning materials are widely applicable in many areas, but the low durability of superhydrophobicity is always a major obstacle for real-world applications. Here we propose a rather simple way to increase durability. We combine electrospinning and polyimides with nano-sized silica to create a durable self-cleaning film. Such films present strong resistance to heat and abrasion, along with thermal insulation. The delicate lotus effect can also be tough and durable.

The fabrication of hydrogels with excellent self-healing properties and high mechanical strength has become a challenging and fascinating topic. The aim of this study is to fabricate a novel robust PAS hydrogel with self-healing properties. The self-healing mechanism and possible interactions between PAS chains of the hydrogel are proposed.

The rapid development of modern technology has put forward higher requirements on thermal insulation materials in many fields. Due to the inevitable defects of common insulation materials, a novel super-insulation material with high performance should be explored. In this article, a flexible, sandwiched super-insulation polyimide (PI) fabric has been designed and fabricated by using an electrohydrodynamic jet technology simply. This unique sandwiched fabric possessed an ultra-low thermal conductivity (16.7 mW m−1 K−1), excellent mechanical properties and a wide operating temperature range. Furthermore, it still has some other multifunctions, such as great cryogenic resistance, self-extinction and thermal stability. Such a sandwiched PI fabric with remarkable integrated performance will have potential engineering applications under harsh conditions, such as the aerospace field.