Applications of Polymer Nanofibers. Группа авторов. Читать онлайн. Newlib. NEWLIB.NET

Автор: Группа авторов
Издательство: John Wiley & Sons Limited
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Жанр произведения: Химия
Год издания: 0
isbn: 9781119267706
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structure. In Figure 2.16, An et al. arranged electrospun nanofibers with the orthogonal direction in virtue of intelligent control (An et al. 2016). It was by means of giving electrical drive to the charged polymer jets, which led to the bending and looping of the jets.

      There are also many hybrid nanofibers with conventional fiber fabrics for combining mutual advantages. Bagherzadeh et al. produced a multilayered fabric with PU nanofibers layered into a sandwich of woven fabric for use as a breathable barrier textile material (Wang et al. 2016). The resultant fabric displayed low air permeability that resulted from small pore sizes but presented good water vapor permeability (Bagherzadeh et al. 2011). Wang et al. used sandwiched polyimide nanofiber/carbon woven fabric for capturing PM 2.5 particles. The maximum air filtration efficiency reached 99.99%.

      Nanofiber fabric products are performed as individual materials in particular applications because of their unique properties. Researchers are taking advantage of nanofiber fabrics, developing many new application fields for them, in terms of protective clothing, filtration, wearable devices, biomedical applications, etc. (Zhu et al. 2016; Thenmozhi et al. 2017). Nanofiber fabrics, especially nonwoven type, are often set as interlayers among sandwich structure, which can guarantee the mechanical strength and filtration performance for some applications, such as filtration and protective clothing. Also in other applications, nanofiber fabrics are used as substrates for carrying functional materials. For instance, nanofiber fabrics can be used to load active materials in the field of energy storage and carry drugs in medical applications. The applications of nanofiber fabrics are introduced and discussed below in details.

      2.5.1 Protective Clothing

      Protective clothing is used to protect human bodies from dangerous environments, such as in high‐risk industries (e.g. hazardous chemicals, flame) as well as outdoor adventures such as in severe weather. Breathable and barrier functional clothing is one of the most attractive aspects of protective clothing (Thenmozhi et al. 2017). Synthetic fibers with high mechanical performance, combustion‐resistant organic fibers, high‐performance inorganic fibers, and so on, are all involved for this end‐use (Zhou et al. 2005). Using nanofiber fabrics as the effective interlayer is a promising design to offer enhanced barrier performance because of the size effect compared with common nonwoven fabrics. Besides, in order to satisfy the purpose of comfort, water vapor diffusion, and air permeability are commonly considered in the application of protective clothing.

      2.5.2 Filter Fabrics

      Nanofiber fabrics are characterized by high surface area and high absorptivity, which have been considered as important characteristics for air and water filtrations. Particularly, with the decrease of air quality, air filter media are getting more attention, such as dust masks, engine air filtration. The usage of nanofibers is a benefit for improving filtration efficiency because of their smaller pore size and larger surface collection area (Zhang et al. 2010).

      Based on good air filtration properties, Li and coworker designed a gauze mask product to prevent inhaling PM 2.5 particles by using an electrospun polysulfone nanofiber fabric (Li and Gong 2015). The result indicated that the prepared nanofiber mask demonstrated a high rejected effect larger than 90% and acceptable air permeability which was probably due to the nanoscaled fiber size. Typically, the rejected effect and air permeability property could not be satisfied simultaneously. For instance, in some cases, in order to meet the requirement of rejected effect, the fabric in the mask would be thicker, which would affect the air permeability.

Schematic illustration of the structure of (a) three-layered and (b) five-layered PI nanofiber/carbon woven fabric composite filter, (c, d) diagram and digital photos of the composite filters.

      Source: (a–d) Wang et al. (2016); (d) Reproduced with permission from Wang et al. (2016). Copyright 2016, Elsevier.

      2.5.3 Wearable Devices