In this study, antistatic sheath-core composite fibers with the core composed of polyethylene terephthalate (PET) polymer and a sheath composed of carbon black/polybutylene terephthalate (CB/PBT) ...polymer were fabricated using a conjugate spinning process. CB powders of various particle sizes were compounded with PBT polymers to prepare the antistatic CB/PBT pellets, and their electrical resistivities strongly depended on the intrinsic properties and dispersion of CB powders. The CB/PBT/PET fibers consisted of well-mixed CB powders within the polymer matrix showed an outstanding antistatic function, and they were employed to manufacture an antistatic glove with commercial acrylic yarns for practical applications. The antistatic glove with a reliable washing fastness is capable of being used on capacitive touch panels of smart phones, tablets, and other wearable electronic devices. This approach offers new possibilities for a variety of textile applications requiring antistatic properties.
In this study, multi-component antistatic fibers with segmented pie structures were prepared by conjugate spinning of carbon black (CB)/polybutylene terephthalate (PBT) and polyethylene terephthalate ...(PET) polymers. The antistatic property of the CB/PBT/PET fibers can be attributed to two factors: thorough mixing of the CB powder in the polymer matrix, and the close contacts formed between the segmented pie fibers. The fibers were woven and knitted into fabrics whose washing durability and antistatic properties were also tested. The surface resistivity of the woven and knitted fabrics did not change significantly (1.1 × 106 Ω/cm2 to 1.2 × 106 Ω/cm2) even after washing the fabrics 100 times. Thus, these fabrics can be used in a variety of applications that require antistatic materials.
•A mixture feed showed a more representative evaluation of membrane fouling potential.•Membrane surface properties dominated the fouling effect at the initial stages of filtrations.•A feed with a ...single foulant resulted in an underestimation of the filtration resistance.•A Feed with a single foulant resulted in an overestimation of the irreversible fouling.•Interactions among foulants should be considered in evaluating membrane fouling.
The biofouling mechanism of organic mixtures on porous polyvinylidene fluoride membranes was tested to determine how to examine the fouling potential of a membrane for water treatments with more representative feed compositions including protein, polysaccharides, and natural organic matters. The three-dimensional structure and compositions of the fouling layers were examined using confocal laser scanning microscopy and the filtration resistances of the fouled membranes were estimated. The filtration resistance analyses demonstrated that feeds with a single-component foulant will cause serious clogging in the pores and form a looser fouling layer structure on the membrane; however, a mixed composition resulted in less clogging in the pore and a denser layer structure on the membrane because of over-deposition and interactions among the foulants. The fouling potential of a membrane examined with a single-component will result in an under-estimation of the filtration resistance of the fouling layer and an over-estimation of irreversible fouling.
Display omitted Wastewaters composed of proteins, polysaccharides, and natural organic matters, as well as their binary and tertiary mixtures were adopted for cross-flow filtration experiments through the polyvinylidene fluoride (PVDF) membranes. The effects of membrane characteristics on membrane fouling, filtration resistances of the fouled membranes, and operating conditions were estimated in this study.
Artificial antistatic fibers due to their low cost as well as providing desirable properties based on their constitutive components, have attracted considerable interests. In the present study, ...bicomponent antistatic fibers with various cross-sectional configurations (i.e. core/sheath and segmented-pie structures) were produced using the mixture of carbon black/dispersing agent/PBT and polyethylene terephthalate. To investigate their practical application, woven fabrics were produced and then examined upon their antistatic characteristics as well their thermal properties, wash durability and breaking strength and elongation. Moreover, the effect of dispersing agent during fiber spinning was examined. Among the produced fibers with different structural configuration, it was concluded that the core/sheath antistatic fibers exhibited higher breaking strength and elongation, as well as lower electrical resistivity. Rheological investigations based on the pressure tests indicated that the homogeneous distribution of the fillers (e.g. carbon black) within the polyester pellets is required for manufacturing the uniform fibers. Moreover, it was determined that surface resistivity of the fabrics could be kept unchangeable even after 20 times of washing, revealing their reliable wash durability. Finally, it was found out that the mixture of carbon black/dispersing agent/PBT provides such desirable conductivity; also, the fabrics comprised of fibers with core/sheath configuration could be a good candidate for antistatic applications within the textile industry.
Several proteomic techniques were used to determine the cleavage site of the mature antimicrobial peptide of Nile tilapia β-defensin. The computer-predicted Nile tilapia β-defensin ...(25ASFPWSCLSLSGVCRKVCLPTELFFGPLGCGKGSLCCVSHFL66) composed of 42 amino acids was chemically synthesized and prepared to produce an antibody for Western blotting. Total proteins from the skin of the Nile tilapia were separated on two-dimensional electrophoresis, and the spot of Nile tilapia β-defensin was recognized using Western blot analysis. It was then excised and extracted from the gel. The precise molecular mass of this spot was determined by LC-MS/MS spectrometry. Four major peptides were discovered, with molecular weights of 4293.2 Da, 4306.5 Da, 4678.9 Da, and 4715.0 Da. The calculated mass of the 40-amino-acid sequence (27FPWSCLSLSGVCRKVCLPTELFFGPLGCGKGSLCCVSHFL66) of Nile tilapia β-defensin starting from Phe27 and ending with Leu66 was 4293.18 Da, which completely matched the 4293.2 Da peptide that was obtained from the mass spectrometry analysis. This result confirmed that the cleavage site for the mature C-terminal Nile tilapia β-defensin is at residue Ser26-Phe27, not at Ala24-25 as predicted by computer analysis. This study provides a simple but reliable model to determine the cleavage site for a mature antimicrobial peptide.
•The cleavage site of mature Nile tilapia β-defensin was confirmed.•Computer-predicted β-defensin was synthesized to produce Ab for Western blotting.•The spot of β-defensin was recognized and extracted from the 2-DE gel.•The precise molecular mass of this spot was determined by LC-MS/MS spectrometry.•The calculated mass of a sequence was completely matched the LC-MS/MS result.
This study improved the photocatalytic activity of NaTaO3 by replacing some Na ions in the 12-coordinate sites with larger K ions. Na1-xKxTaO3 photocatalysts of x = 0-0.2 were synthesized by the ...sol-gel method. K-doping at x = 0.05 resulted in rectifying the distorted perovskite NaTaO3 to a pseudo-cubic phase as well as significantly promoting the photocatalytic activity. The 180degree bond angle of Ta-O-Ta in the pseudo-cubic phase may facilitate the separation of photogenerated charges for effective water splitting. Photoluminescence spectroscopic analysis confirmed that the flattened Ta-O-Ta linkage with K-doping suppresses the recombination of photogenerated charges. Further K-doping (with x 0.05) leads to impurity formation, which bends the Ta-O-Ta linkage and creates defect states, lowering the photocatalytic activity of the K-doped NaTaO3. This study demonstrates that an appropriate ion replacement to tune the crystal structure can significantly promote electron transport in photocatalysts and thus their activity.
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