Electroless plating process for the manufacture of radiation protection suits for pregnant woman: Effect of bending on its electromagnetic shielding performance

Multi-ion fabrics (especially silver ion fabrics) have special advantages as electromagnetic radiation, but the use of noble metals enhances its cost. Electroless nickel plating (EP-Ni) has great potential application in fabricating low-cost metallized material. Here, EP-Ni on pure cotton surface to fabricate radiation protection suits for pregnant woman was established to replace traditional protection suits with silver film. The active groups on the cotton/polyester blend fiber surface could absorb tin and palladium ions, acting as catalytic centers, which can catalyze the reduction of Ni2+ in the plating solution. Ni particle with (111) crystal plane preferential oriented crystal structure deposited on cotton surface with a coarse microstructure. The Ni deposited amount is about 19%. The fabricated material exhibited a shielding effectiveness of 29.5 dB. Studies also shown that bending has no negative effect on crystallinity and electrical property. But more bending times could lead to crack, which would decline electromagnetic shielding performance by 24%.

Electrospinning and Catalytic Properties of Cyclodextrin Functionalized Polyoxymethylene (POM) Nanofibers Supported by Silver Nanoparticles

A series of novel composite microfibers composed of β-cyclodextrin (β-CDs) functionalized POM (polyoxymethylene) were prepared using electrospining technology with a mixture of hexafluoroisopropanol (HFIP) and N,N-dimethylformamide (DMF) as solvent. The concentration of β-CDs with respect to the POM was varied from 0 to 50 wt.%. The effect of β-CDs content on the morphology of POM/β-CD composite microfiber was investigated. The results showed that the introduction of β-CDs reduced the surface roughness and porosity of the microfibers, and the morphology of the fibers was changed. The increase of β-CDs content from 10% to 50% has led to increased average diameter of POM/β-CD composite fiber from 2.1 μm to 6.4 μm. The mechanical properties of the blend fiber mats were further investigated. In addition, silver nanoparticles were introduced to the POM/β-CD composite microfiber matrices during electrospinning. The POM/β-CD composite fiber allows CDs to form host–guest complexes with various small molecules and macromolecules. The TEM, SEM, XRD, and XPS were utilized to characterize the prepared samples. The data suggest that Ag nanoparticles were homogeneously distributed within the POM/β-CD fibers, and no aggregation was observed. The catalytic activity of Ag nanoparticles was tracked by ultraviolet-visible (UV-vis) spectroscopy which showed excellent catalytic degradation performance of organic dyes in the presence of NaBH4. The Ag/POM/β-CD mats are promising for use in waste treatment, molecular recognition, catalysis, and so on.

Zeolite/Cellulose Acetate (ZCA) in Blend Fiber for Adsorption of Erythromycin Residue From Pharmaceutical Wastewater: Experimental and Theoretical Study

The expanding amount of remaining drug substances in wastewater adversely affects both the climate and human well-being. In the current investigation, we developed new cellulose acetic acid derivation/zeolite fiber as an effective technique to eliminate erythromycin (ERY) from wastewater. The number of interchangeable sites in the adsorbent structures and the ratio of ERY to the three adsorbents were identified as the main reasons for the reduction in adsorption as the initial ERY concentrations increased. Additionally, for all adsorbents, the pseudo–second-order modeling showed better fitting for the adsorption than the pseudo–first-order modeling. However, the findings obtained in the pseudo–first-order model were still enough for explaining the sorption kinetics of ERY, showing that the surface displayed all chemisorption and physi-sorption adsorption processes by both adsorbents. The R2 for the second order was very close to 1 for the three adsorbents in the case of pseudo–second-order. The adsorption capacity reached 17.76 mg/g. The three adsorbents showed negative values of ΔH, and these values were −6,200, −8,500, and −9600 kJ/mol for zeolite, CA, and ZCA, respectively, and this shows that the adsorption is exothermic. The desorption analysis shows no substantial loss of adsorption site after three trials, indicating higher stability and resilience of the three adsorbents, indicating a strong repeatability of their possible use in adsorption without contaminating the environment. In addition, the chemical attitude and possible donor–acceptor interactions of ERY were assessed by the quantum chemical parameters (QCPs) and NBO analysis performed, at the HF/6-311G** calculations.

Effect of Copoly(Ester-Amide 6)(PET-PA6) on Compatibility of PET/PA6 Blended Fibers

Significant improvement of compatibility in PET/PA6 blends is essential to obtain fibers having enough mechanical strength as well as the comprehensive performance. In this article, copoly (ester-amide 6) was used as compatibilizer to improve the compatibility of PET and PA6. Three copoly (ester-amide 6) s with 5, 10% content of PA6 were prepared by co-polymerization from PTA , EG, as well as PA6 or caprolactam (A6), i.e. polyamide was incorporated both in the form of polymer and monomer, respectively. The sequence length of PET in the copoly (ester-amide 6) s is 33.4, 16.5 and 38.4 for PET-PA6-5%, PET-PA6-10% and PET-A6-5%, respectively, calculated by 13C NMR. Then PET/PA6 blend fibers were fabricated by melting spinning of PET and PA6 with 20 %wt addition of PET-PA6-5%, PET-PA6-10% and PET-A6-5%, respectively, to explore the effect of copoly (ester-amide 6) s on compatibility of PET/PA6 blend fibers, where the mass ratio of PET and PA6 is 85/15. DSC results show that the crystallization peaks of PET and PA6 during cooling from the blend melt become adjacent each other with increasing addition of copoly (ester-amide 6) s, even forming fused crystallization of them. It was found from SEM that the size of PA6 phase decreased and the phase boundary became indistinct due to the presence of copoly (ester-amide 6) s. Further more, the glass transition temperatures (Tg) of PET and PA6 closed to each other based on DMA result. Among these three copoly (ester-amide 6) s, PET-A6-5% display the best effect on the compatibility of PET and PA6 blend fiber, suggesting copoly (ester-amide 6) s could play important role in raise the compatibility of PET and PA6 blend.

Melt-Electrospun Polyethylene Nanofiber Obtained from Polyethylene/Polyvinyl Butyral Blend Film

We prepared low-density polyethylene (LDPE) nanofiber, a few hundred nanometers in diameter, using polyvinyl butyral (PVB) and a laser melt-electrospinning (M-ESP) device. We blended PVB with LDPE via an internal melt mixer, removed the PVB after M-ESP by ethanol treatment, and studied the influence of PVB on fiber diameter. A substantial diameter reduction with improved crystallinity of LDPE fiber was observed with increased PVB content in the blend. PVB inclusion also increased the polarity of the LDPE/PVB blend, resulting in better spinnability. The removal of PVB from LDPE/PVB blend fiber caused a massive drop in the LDPE fiber diameter, due to fiber splitting, particularly in PVB-rich samples. Fourier transform infrared (FTIR) spectroscopy of fibers confirmed that the prepared nanofiber was the same as pure LDPE fiber.

Influence of Incorporated Polydimethylsiloxane on Properties of PA66 Fiber and Its Fabric Performance

Poly(hexamethyllene adipamide), PA66 fiber has played an important role in varied industrial applications, and its corresponding product would become more competitive if some extra value was added to PA66 fiber. In this article, polydimethylsiloxane (PDMS) was used as an additive to prepare PA66/PDMS blend fibers through melt blend spinning carried out by a screw extruder spinning machine. When the amount of incorporated PDMS was 0.5–3 wt %, the blend melt demonstrated good spinning ability, and the PA66/PDMS blend fibers exhibited excellent mechanical property and reduced hot shrinkage. Moreover, the crystallization and melting behavior of PA66 in the blend fibers turned out to be not affected by the existence of PDMS. In addition, the contact angle of water on the blend fiber surface became larger, while the value of friction coefficient on the surface of fibers got lower with increasing PDMS content in the blend fibers. After evaluating the fabric woven by PA66/PDMS blend fibers using the KES-F KES-FB-2 fabric measuring system, it was found that as PDMS content increased, the flexural rigidity and bending hysteresis would be lower, yet elasticity rate of compression work would be higher, which explained how the fabric composed of the blend fiber performed better in terms of softness and elasticity.