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Nanocellulose has become an attractive biodegradable material for surface-enhanced Raman scattering (SERS) sensors. However, the development of nanofibrillar cellulose-based SERS substrates that are simultaneously flexible, highly sensitive, uniform, and stable remains a great challenge. Herein, a highly sensitive, reliable, and flexible gold nanoparticle-decorated bacterial nanocellulose (AuNPs@BNC) SERS substrate with three-dimensional (3D) high-density hot spots was constructed by the combination of in situ chemical reduction and vacuum filtration. The homogeneous AuNPs were grown in situ on the surface of networked bacterial cellulose nanofibers to form 3D high-density SERS hotspots. In addition, the hydrophilic BNC with good adsorption and permeability properties could capture target molecules in the high-density hotspot region to further enhance the SERS performance. As a result, the 3D AuNPs@BNC SERS substrate not only demonstrates a high detection sensitivity of up to 1.0 × 10–10 M and an enhancement factor of 1.8 × 107 for methylene blue molecules but also shows excellent signal reproducibility (relative standard deviation (RSD) = 8.3%) and long-term storage stability (over two months). Furthermore, the flexible 3D AuNPs@BNC SERS substrate is also able to detect trace malachite green (MG) with a low detection limit of 1.0 × 10–11 M and prominent signal homogeneity of RSD = 7.8%. Besides, hazardous MG residues on the surface of shrimp could be directly identified by using flexible AuNPs@BNC SERS substrates through a feasible wipe-and-peel method. The flexible, reliable, and stable AuNPs@BNC substrate is promising for direct, sensitive, and rapid on-site detection of toxic molecules on seafood. [ABSTRACT FROM AUTHOR]

Lotus stems were treated with sodium hydroxide followed by sodium chlorite to prepare lotus fibers. The lotus fibers were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FTIR), X-ray diffraction (XRD), and thermogravimetric (TG) analysis. The crystallinity and crystallinity index of lotus fibers are 62.11 and 62.29%, respectively. The content of cellulose in lotus fibers after being purified with sodium chlorite is improved and reaches 69.74%. The moisture regain of lotus fibers was studied and the results show that moisture regain of purified lotus fibers is 6.87%. The influences of concentration of sodium chlorite on tensile strength and breaking elongation of lotus fibers were investigated. The tensile strength and breaking elongation of lotus fibers both decrease as the concentration of sodium chlorite increases. The results are expected to provide valuable guidance for preparing lotus fibers from lotus stems through chemical treatment. [ABSTRACT FROM AUTHOR]

In this study, a visible-light-driven photocatalyst BiWO was assembled on fibers by linking of poly(diallyldimethylammonium chloride) (PDDA) at room temperature. The samples were characterized by scanning electron microscopy, energy-dispersive spectroscopy and X-ray diffraction. Photocatalytic activity was evaluated by degradation of Rhodamine B (RhB) and Acid orange 7 (AO7) under visible light irradiation. Effects of concentration of PDDA in the pretreatment solution on degradation efficiency of RhB and AO7 in the presence of BiWO coated cotton fabrics were investigated. In addition, washing durability and breaking strength of BiWO coated cotton fabrics modified with PDDA were examined. The results revealed that BiWO with irregular shape were successfully coated on the cotton fabric modified with PDDA. BiWO coated cotton fabric modified with PDDA exhibited excellent photocatalytic activity with degradation efficiency of 97.4% of RhB and 94.5% of AO7, respectively. In addition, BiWO coating on the cotton fabrics modified with PDDA not only improved washing durability but also enhanced breaking strength of the fabric. [ABSTRACT FROM AUTHOR]

Bismuth tungstate/lotus fiber composite membrane (Bi 2 WO 6 /LF) were prepared. The composite membranes were characterized by scanning electron microscopy (SEM), energy dispersive spectrum (EDS) and X-ray diffraction (XRD). The photocatalytic activity of Bi 2 WO 6 /LF under visible light irradiation was investigated. The result shows that photocatalytic activity of the Bi 2 WO 6 /LF increase with the rise of Bi 2 WO 6 content in the composite membrane. Bi 2 WO 6 /LF with 1% Bi 2 WO 6 possesses excellent photocatalytic activity for methylene blue and degradation efficiency of methylene blue reach 94% after irradiation for 270 min. Bi 2 WO 6 /LF could be potentially applied in sewage disposal and environmental remediation. [ABSTRACT FROM AUTHOR]

BiWO particles were prepared and then coated on the polyester fabric. Surface morphology, crystal structure, and chemical structure of the BiWO particle coated polyester fabric were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Photocatalytic activity was evaluated by the degradation of methylene blue (MB) under ultraviolet light irradiation. Influences of the different concentrations of BiWO on the deposit weight and the photocatalytic activity of the BiWO particle coated polyester fabric were investigated. In addition, UV protection of the BiWO particle coated polyester fabric was examined. The results show that BiWO particles are uniformly coated on the surface of the polyester fabric. The BiWO particles coated on the polyester fabric are irregular and are orthorhombic. In addition, the BiWO particle coated polyester fabric exhibits excellent photocatalytic activity and UV protection. The average degradation efficiency of MB in the presence of the BiWO particle on the polyester fabric coated with 10 g/ l BiWO reaches 98.6 % after being illuminated for 7 h. Therefore, the BiWO particle coated polyester fabric shows excellent photocatalytic stability for dyes degradation. [ABSTRACT FROM AUTHOR]

Lotus fibers were prepared from lotus stems through being treated with sodium hydroxide. The lotus fibers were characterized by scanning electron microscopy (SEM), fourier transform infrared spectrometry (FTIR), X-ray diffraction (XRD) and thermal analysis (TG and DTA). The results indicate that the length of lotus fibers ranges from 3.52 cm to 5.80 cm and the width of lotus fibers ranges from 50 μm to 90 μm. Lotus fibers belong to celluloses fiber with cellulose I structure and the crystallinity of lotus fibers is 48.50 %. The lotus fibers consist of cellulose, lignin, hemicellulose, pectin, lipid and water-soluble substances. The effect of concentration of sodium hydroxide, time and temperature of treatment on removal of impurities, fineness and breaking strength of lotus fibers were investigated. The results suggest that the removal of impurities and breaking strength increase with the rise of concentration of the sodium hydroxide, time and temperature of treatment, respectively. However, the fineness of lotus fibers decreases with an increase in concentration of the sodium hydroxide, time and temperature of treatment. The results are expected to provide valuable guidance for preparation of lotus fibers through simple treatment with sodium hydroxide, which can be applied in textile industry. [ABSTRACT FROM AUTHOR]

The environmental repercussions of wastewater from the dye process mean that it is very important to obtain an eco-friendly photocatalyst that would degrade wastewater. Herein, bismuth tungstate/graphene oxide (Bi2WO6/GO) composites are fabricated through in-situ hydrothermal reaction and then the Bi2WO6/GO photocatalysts are deposited onto polyethylene terephthalate (PET) fabric. The obtained Bi2WO6/GO deposited PET fabrics are then characterized through XPS, Raman, SEM, TEM, XRD, UV-vis, BET method and photoluminescence spectroscopy (PL) to investigate their chemical and crystal structures, morphology, optical property, surface area and photochemical properties. Photocatalytic performance is studied through examining the rate of degrading rhodamine B (RhB) under visible light. Surface of PET fibers is densely covered with Bi2WO6/GO. Bi2WO6/GO deposited PET fabrics show a broad absorption band in the visible spectra. Removal rate of RhB on the Bi2WO6/GO deposited PET fabric is the highest with the GO content of 2 g/L (labeled as Bi2WO6/2 g/LGO). The result of active species experiment shows that superoxide radicals (·O2−) plays a major role in the degradation of RhB. Moreover, Bi2WO6/2 g/LGO deposited PET fabric shows excellent cycle stability of photocatalytic degradation for RhB. The findings in this work can be extended to preparation other types of composite on the textile for photocatalysis, which can be applied to remove dyes in the wastewater produced by the textile or leather industry. [ABSTRACT FROM AUTHOR]