Table of Content - JFBI 2.4

Silk contains a fibre forming protein, fibroin, which is biocompatible, particularly after removing the potentially immunogenic non-fibroin proteins. Silk can be engineered into a wide range of materials with diverse morphologies. Moreover, it is possible to regenerate fibroin with a desired amount of crystallinity, so that the biodegradation of silk materials can be controlled. These advantages have sparked new interest in the use of silk fibroin for biomedical applications, including tissue engineering scaffolds and carriers for sustained release of biologically active molecules. This article summarizes the current research related to the formation of silk materials with different morphologies, their biocompatibility, and examples of their biomedical applications. Recent work on the preparation of silk particles by mechanical milling and their applications in silk composite scaffolds is also discussed.

We discuss the perspectives of structural colored fibers based on the photonic crystal structures. These fibers display the distinctive colors, which are determined by the lattice constants of the photonic crystals. We demonstrate the color-changing capability of photonic fibers with potential applications in dynamic signage and environmentally adaptive coloration. The fibers are fabricated by the silica or polystyrene colloidal particles to the periodically ordered interconnecting structure in a cylindrical shape. The visible light is coherently diffracted on the surface of the fibers, which produces a shinning color in a narrow range of wavelength. Importantly, no dyes or colorants are used in fabrication of such fibers, thus making the fibers resistant to color fading. This method of making colorful fibers could be a promising way to reduce environmental pollution in the dying industry. Additionally, by changing the reflective index or lattice constant of a photonic fiber, its reflected colors change proportionally to the shift of reflective index or lattice constant, thus enabling visually interactive and sensing textiles responsive to the external stimuli.

Reactive quaternary ammonium salt of chitosan (RQC) with quaternary ammonium salt and reactive carbon double bonds was synthesized in two steps in order to improve the solubility and reactive properties of chitosan. Quaternized chitosan were first obtained by heterogeneous reaction of chitosan and 2, 3-epoxypropyltrimethyl ammonium chloride using isopropyl alcohol as dispersing solvent. Then RQC was prepared using the quaternized chitosan and N-(hydroxymethyl)-acrylamide. FTIR was used to characterize the structure of the synthesized RQC, and the results show that H of -NH2 in chitosan molecules was substituted with -CH2CH(OH)CH2N+(CH3)3 and H of OH in RQC molecule was substituted with -CH2NHCOCH=CH2. Antheraea pernyi (A. pernyi) silk was then modified with RQC by padding and curing method. The results revealed that the dyeing depth of treated A. pernyi silk dyed with reactive dyes increased greatly in comparison with the untreated and chitosan treated ones, and the bacterial reduction against S. aureus and E. coli of the treated A. pernyi silk fabric was more than 98% even after 20 launderings.

Today, many photosensitive polyimide (PI) materials have been studied for their excellent thermomechanical, low dielectric constants. So, two hemicyanine dyes, named as DHEASPBr-C4 and DHEASPBr - C8, have been synthesized in this paper and incorporated by doping to polyamic acid (PAA) in N, Ndimethylacetamide (DMA) solution to prepare for the fluorescent PI nanofibers. Firstly, PAA nanofibers were achieved using electrospinning process (ESP) at room temperature. 4 hours later, polyimide (PI) nanofibers have been successfully obtained by thermal imidization in vacuum oven while temperature was 200 0C and vacuum degree was 133 Pa. Results showed that the one-photon emission fluorescence peaks of two hemicyanine dyes in N, N—Dimethylformamide (DMF) solution were located at 606 nm and 613 nm respectively. While all mats consisted of those PAA nanofibers or PI nanofibers showed good fluorescent properties and their one-photon emission fluorescence spectra were located around 600 nm. So, nanofluorescent PI Fibers can be prepared by electrospinning technique.

This study tried to introduce porous technology into functional textile’s formation, and developed a new way to improve working materials content in phase change material. Porous polyurethane (PU)/ polyethylene glycol (PEG) membrane was prepared and selected as a supporting material. Considered to be convenient for filling, anhydrous ethanol was used to decrease PEG viscidity according to the rule of similarity. The solution of PEG and anhydrous ethanol was filled into porous PU/PEG membrane by vacuuming and then PU dry-film technology was used for the sealing of the membrane hole. The effects of PEG mass percentage in ethanol solution on filling rate and the filling rate on the membrane morphology and mechanical properties were studied. The results show that, the filling rate increased with the increase of PEG content in the blending solution. As the filling rate increased, the elongation at break decreased obviously, while the initial modulus increased largely. After sealing the filled membrane using PU dry-film technology, the initial modulus of the membrane decreased, while the elongation at break increased. In addition, DSC analysis indicates that the sealed membrane and pure PEG show similar thermal properties, while the compound membrane can retain its solid shape during phase change.

This paper evaluates and compares the electromagnetic (EM) shielding characteristics of a diverse range of conductive fabrics in order to analyse their suitability for use in wearable medical applications. The Shielding Effectiveness (SE) was characterised in terms of fabric structures, conductive materials, mass, thickness and washing durability. Experiments were carried out on single and double layers of fabrics using broad frequency range and SE was measured using different methodologies. EM shielding is the process of limiting the flow of EM fields between two locations by a barrier. The shielding barrier needs to have high conductivity, dielectric constant or high magnetic permeability, and the shielding happens due to reflection, absorption or multiple reflections of the incident radiation by the barrier. Therefore, shielding is important to block electromagnetic radiation that could be harmful to electronic devices, environment and humans.

With the help of electronic microscope and scanning electronic microscope, profiled polyester fibers with cross section shapes like “Y”, “＋” and “C” were analyzed individually. Four kinds of single and double-faced knitted fabrics with different structures and density were manufactured with the profiled polyester fibers, and their wicking height, water retention and drying efficiency were investigated individually. It was found that the more abnormal the fiber cross section is, the better is the moisture-transfer and fast drying properties of its fabrics.

Polyaniline/Fe3O4 nanoparticle composite was prepared by microemulsion in-situ polymerizing aniline in the presence of Fe3O4 nanoparticles upon the use of ammonium persulfate(APS) as the initiator, hydrochloric acid(HCl) as intermingling acid, cetyltrimethylammonium bromide (CTAB) as emulsifying agent and normal butanol as auxiliary emulsifying agent. The results revealed that a core-shell structure composite was obtained successfully. Further more, pure PANI solution was not able to be electrospun into the fibrous structure, so electrospinning of emeraldine base Fe3O4-polyaniline/ polyacrylonitrile (Fe3O4-PANI/PAN) blends with different composition ratios were performed using N,N-Dimethylformamide as solvent. Morphology and fibers diameters were investigated by scanning electronic microscopy (SEM). The fibers with diameter ranging from 168 to 300 nm were obtained. The ratio of polyaniline/ Fe3O4 to PAN was fixed at 3:8. Scanning electron microscopy indicated that the diameter of the composite nanofiber increased with the content of Fe3O4.

This paper focuses on the development of a multi-structural computational scheme for textile thermal engineering design, which plays an important role in translating complex mathematical models into computational algorithms and to implement computational simulation of clothing wearing system consisting of human body, clothing and external environment. In this paper, the integrated models for simulating the clothing wearing system is introduced and the descretization process of the partial differential equations involved in the mathematical models is reported. Based on the descretized equation assemblies, the multi-dimensional algorithms for computational simulation are developed for clothing thermal engineering design. Furthermore, the influence of the physical properties of clothing on the simulation results is analyzed to guide the user to design the desirable thermal performance of clothing.

Well-dispersed multiwalled carbon nanotubes (MWNTs)/polyethylene composites have been prepared from melt blending, and composite fibers were prepared via direct melt extrusion of immiscible blends with CAB and subsequent removal of CAB matrix. Scanning electron microscopy was employed to observe the distribution of the MWNTs in the composites, indicating a nanotube network formed in the matrix. SEM images also investigated that the average diameter of PE/MWNTs nanofibers can be 300-400nm. In addition, the crystalline structures of the CNTs/PE nanofibers were characterized by DSC, WAXD and POM, which show a decrease in the crystallinity of PE due to the addition of MWNTs. The thermal properties of composite fibrils were also modified. This fabrication process possesses features of controllability and is environmental friendly during the manufacture of thermoplastic nanofibers.