The efficacy of coconut fibers on the sound-absorbing and thermal-insulating nonwoven composite board

The aim of this study is to examine the efficacy of the coconut fiber on the sound absorption and thermal insulation performance towards the composite nonwoven fabrics. The 2D polyester fiber and 12D fire retardant three-dimensional hollow crimp polyester fiber are individually mixed with 4D low-melting point polyester fiber (4DLMf) to produce 2D polyester nonwoven fabric (2D-PETF) and 12D polyester nonwoven fabric (12D-PETF) respectively. Subsequently, the coconut fiber (CF) is then laminated with the 2D-PETF and 12D-PETF to fabricate two types of PET/CF composite boards through the multiple needle-punching techniques. Accordingly, the sound absorption, thermal insulation, Limiting Oxygen Index and relative mechanical properties of the PET/CF composite boards are evaluated properly. The experimental results reveal that both types of PET/CF composite boards possess excellent thermal insulation performance and fire resistance property. Also, for both types of PET/CF composite boards, the average sound absorption coefficient increases with the increased amount of CF.     

Preparation of cellulose/multi-walled carbon nanotube composite membranes with enhanced conductive property regulated by ionic liquids

Cellulose/multi-walled carbon nanotubes (MWCNTs)- composite membranes applied in electrochemical and biomedical fields were prepared using 1-ethyl-3-methylimidazolium diethyl phosphate (EmimDEP) as solvent in this study. With the increasing of MWCNTs amount, the membrane conductivity increased, and the conductivity reached 9.1 S/cm as the mass ratio of MWCNTs to cellulose being 2:1. The additions of sodium dodecyl sulfate (SDS), 1-hexadecyl-3-methylimidazolium bromide (C₁₆mimBr) and 1-butyl-3-methylimidazolium tetrafluoroborate (BmimBF₄) efficiently improved the conductivity, mechanical property, and thermal stability by promoting the dispersion of MWCNTs. When the mass ratio of C₁₆mimBr to MWCNTs changed from 0 to 0.3:1, the conductivity increased from 0.08 S/cm to 0.14 S/cm, and the tensile strength increased from 13.3 MPa to 17.0 MPa. These results indicate that the binary ionic liquids (ILs) system can regulate the properties of the composite membranes, and is a feasible approach for preparing cellulose/MWCNTs composite membranes with enhanced properties.     

Preparation of the silk fabric with ultraviolet protection and yellowing resistance using TiO2/La(III) composite nanoparticles

In order to develop ultraviolet protection and yellowing resistance silk fabric, the silk fabric was treated with dispersive TiO₂/La(III) composite solution. The morphology, microstructure, ultraviolet protection and whiteness of the treated silk fabric were characterized by means of transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectra, X-ray diffraction and ultraviolet transmittance. Furthermore, the mechanism of the ultraviolet protection was investigated. The results show that the TiO₂/La(III) composite particles disperse uniformly. The TiO₂/La(III) particles can not only be treated onto the surface of the silk fabric but also can be treated into the interior of the silk fabric successfully. The result of Fourier transform infrared spectra and X-ray diffraction demonstrates that there are hydrogen bonds between the silk fabric and composite particles, and crystallinity of the treated silk fabric decrease when compares to the untreated silk fabric. The ultraviolet protection factor of the TiO₂/La (III) treated silk fabric is significantly higher than that of the untreated silk fabric. The main ultraviolet shielding effect of TiO₂ treated silk fabric is absorption. The La(III) treated SF has a bad ultraviolet shielding effect, but it has a certain reflection and absorption.     

Preparation and characterization of PVA/PU blend nanofiber mats by dual-jet electrospinning

A series of blend nanofiber mats comprising poly(vinyl alcohol) (PVA) and polyurethane (PU) were prepared by dual-jet electrospinning in various parameters. Orthogonal experimental design was used to investigate how those parameters affected on fiber diameters and fiber diameter distribution. Altogether three parameters having three levels each were chosen for this study. The chosen parameters were tip-to-collector distance (TCD), voltage and tip-to-tip distance (TTD). Fiber diameters, thermal properties, mechanical properties and hydrophilicity of the blend nanofiber mats were examined by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), tensile test, contact angle and water absorption test, respectively. The results showed that the optimum conditions for PVA/PU blend nanofiber mats fabricated by dual-jet electrospinning were TCD of 20 cm, voltage of 18 kV and TTD of 4 cm. Besides, the thermal stability of PVA/PU blend nanofiber mats had been improved compared with pure nanofibers. Furthermore, the elongation and tensile strength of the blend nanofiber mats were significantly increased compared with pure PVA and pure PU, respectively. And the blend nanofiber mats exhibited well hydrophilicity.     

Preparation and characterization of electrospinning PLA/curcumin composite membranes

In this paper, curcumin-loaded electrospinning Poly(lactic acid) (PLA) composite membranes were prepared. Curcumin with different contents (1, 3, and 5 wt%) was loaded to study its anticoagulation property as a drug-eluting stent. The structure of the composite membrane was analyzed by Fourier Transform Infrared (FTIR) spectroscopy, and the results suggested that both PLA and curcumin were present in the composite membrane without chemical reaction between them. Scanning electron microscopy (SEM) and related analysis revealed that the average diameters of composite nanofibers were between 756 and 971 nm with better uniformity in the range of the experiment, furthermore the average diameters of composite nanofibers decreased with the curcumin content increase; The in vitro anticoagulation behavior of curcumin-eluting stents was investigated through static platelet adhesion test, revealing that the anticoagulation property of composite membranes was superior to the pure PLA membrane, and the anticoagulation behavior significantly improved with increasing curcumin by dint of SEM observation.     

Fabrication,Characterization and Antimicrobial property of natural TTOLs/CS composite sponges

The essential oil liposomes, a kind of ecological friendly natural antibacterial agents, have good bactericidal effect. In the present study, tea tree oil liposomes (TTOLs) were prepared by the thin-membrane hydration method with sonication, and then were blended with chitosan (CS) to successfully fabricate novel TTOLs/CS composite sponges by freeze-dried method. Through the scanning electron microscope (SEM), fourier transform infrared spectroscopy (FTIR) and performance tests, it was found that the material had good water absorption, water retention and water vapor permeability due to the high porosity. Furthermore, the incorporation of TTOLs in the CS-based sponges significantly improved the microbicidel effect of the sponges against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and Candida albicans (C. albicans). Killing log values of TTOLs/CS composite sponges against bacteria and fungi reached over 3. According to the microbial clearance test, propidium iodide (PI) fluorescence test and transmission electron microscope (TEM) observation, the results indicated on one hand that TTOLs/CS composite sponges adsorbed and intercepted microbial cells through the internal pore and surface charge, and on the other hand that they could destroy bacterial intercellular substance, disperse cell colony and damage the integrity of cell membrane, finally leading to the death of microbial cells. In summary, TTOLs/CS composite sponges had great potential to be used as antimicrobial materials in the field of food, cosmetics, medicine, biomedical and biochemical engineering.     

Preparation and property of ultrahigh molecular weight polyethylene/halloysite nanotube fiber

In this research, halloysite nanotubes (HNTs) were incorporated into ultra-high molecular weight polyethylene (UHMWPE) in order to prepare the nanocomposite fibers by a gel-spun and hot drawing process. The HNTs were treated with oleic acid to improve the dispersion in the UHMWPE fibers. Both the crystallinity tested by differential scanning calorimetry (DSC) and mechanical properties increased with a low loading of HNTs, and decreased with a high loading. The thermal gravimetric analysis (TGA) test showed the thermal stability to improve with the incorporation of HNT. The addition of HNT did not change the crystal type, according to the X-ray diffraction (XRD) study.     

Preparation and radiopaque properties of chitosan/BaSO4 composite fibers

Chitin and chitosan have been extensively investigated as a matrix of organic/inorganic composite. Barium, one of the radiopaque inorganic materials, can provide chitosan with radiopaque property by blending of chitosan and BaSO₄. The filtered and deaerated chitosan/BaCl₂ solutions were extruded into NaOH and Na₂SO₄ coagulation bath through a nozzle by gear pump. BaSO₄ was synthesized by the reaction between BaCl₂ and Na₂SO₄ in the coagulation bath, in which acidic chitosan solution was also solidified at the same time. In XRD, the introduction of BaSO₄ into chitosan fibers reduced the inherent peak of chitosan fibers. In angiographic observation, chitosan/BaSO₄ hybrid fibers exhibited the clear contrast images which become clear with an increase in BaSO₄ content.     

Preparation and blood compatibility of electrospun PLA/curcumin composite membranes

In this article, curcumin-loaded electrospun Polylactic acid (PLA) composite membranes were prepared. Curcumin with different concentrations (1, 3 and 5 wt%) was loaded to the PLA membranes to study its anticoagulant property as a drug-eluting stent. X-ray diffraction (XRD) characterization of the prepared membranes indicates that PLA and curcumin mix together well through the method of electrospinning and the composite membrane has larger crystallinity than that of PLA membrane. The in vitro blood compatibility of curcumin-eluting stents was investigated by static platelet adhesion and blood coagulation time (APTT and PT) tests, revealing that the blood compatibility of composite membranes is superior to the pure PLA membrane, and the blood compatibility significantly improves with curcumin concentration increasing by dint of observing SEM images and calculating the inhibition rate of platelet aggregation. Moreover, PLA/curcumin membrane can effectively prolong the blood coagulation time compared with the plasma, and the blood coagulation time of composite membranes improves significantly as curcumin concentration increasing.     

Preparation and acid dye adsorption behavior of polyurethane/chitosan composite foams

We prepared a series of polyurethane(PU)/chitosan composite foams with different chitosan content of 5∼20 wt% and investigated their adsorption performance of acid dye (Acid Violet 48) in aqueous solutions with various dye concentrations and pH values. It was observed that PU/chitosan composite foams exhibited well-developed open cell structures. Dye adsorption capacities of the composite foams increased with the increment of chitosan content in composite foams, because amine groups of chitosan serve as the binding sites for sulfonic ions of acid dyes in aqueous solutions. In addition, dye adsorption capacities of composite foams were found to increase with decreasing the pH value, which stems from the fact that the enhanced chemisorption between protonated amine groups of chitosan and sulfonic ions of acid dye is available in acidic solutions. The dye adsoption kinetics and equilibrium isotherm of the composite foams were well described with the pseudo-second order kinetic model and Langmuir isotherm model, respectively. The maximum adsorption capacity (q _max) for the PU/chitosan composite foams with 20 wt% chitosan content is evaluated to be ca. 30 mg/g.     

Preparation and performance as PEM of sulfonated pre-oxidized nanofiber/SPEEK composite membrane

Building proton transfer channel is an important strategy to optimize the proton transfer process of the proton exchange membrane (PEM). In this work, sulfonated pre-oxidized nanofibers were prepared by solution blowing of polyacrylonitrile (PAN) nanofibers followed by pre-oxidization and sulfonating, and the nanofibers were composited with SPEEK to enhance its performance as PEM. The results of the proton conductivity verified that the employment of sulfonated pre-oxidized nanofibers improved the proton conductivity. Meanwhile, the introduction of the sulfonated pre-oxidized nanofibers realized the upgrades of the thermostability and water absorbency of the membrane, and led to the decrease of the swelling property and methyl alcohol’s permeability of the material. It is indicated that the composite membrane is promising materials for PEM fuel cells.     

Exploration of AgNW/PU nanoweb as ECG textile electrodes and comparison with Ag/AgCl electrodes

This study aims to measure ECG signals by the AgNW/PU nanoweb electrodes, and, to compare with signals measured by the conventional Ag/AgCl electrodes. Finally, to investigate the usage potential of the AgNW/PU nanoweb as ECG textile electrodes. The ECG textile electrodes were fabricated, using the polyurethane (PU) nanoweb (Pardam, s.r.o., Czech Republic) coated with 1 wt% of silver nanowires (AgNW) dispersed in ethanol (KLK Co., Korea). To measure the ECG signals, eight participants (Male:Female=1:1) were collected, and then, the signals were measured at rest-state and stress-state in anechoic chamber using Lead I method. From the measured ECG signals, heart rate (HR) and R-R intervals were acquired by using MP150 (Biopac system Inc., USA) and Acqknowledge (ver. 4.2, Biopac system Inc., USA), and then, analyzed by using Kubios HRV (ver. 2.0., Biosignal Analysis and Medical Imaging Group, Finland). To examine the morphology of the signals, direct visual evaluation was performed. Also, to statistically compare to the signals, Wilcoxon signed-rank test was conducted by using R statistical language and RStudio (1.0.143 ver., RStudio, Inc., USA). As a result, the ECG waveforms measured by the two different types of electrodes looked similar, especially, QRS-complex, P-wave and T-wave as well as R-peaks properly appeared. Also, there was not a significant difference of HR and RR-intervals measured by the two different types of electrodes. It demonstrated that the new AgNW/PU nanoweb electrodes could perform properly as ECG electrodes.     

Preparation and antibacterial property of the mulberry based textiles

The mulberry based textile products were prepared by means of degumming, dyeing, spinning and weaving using mulberry bark as raw materials. The structure of the mulberry based textiles was characterized by scanning electron microscope (SEM). The antibacterial property of the mulberry fibers was evaluated by means of antibacterial testing, and the antibacterial composition in the mulberry based textiles was investigated by FTIR and ¹³C-NMR. The results show that the mulberry based fibers, dyed fibers, yarns and fabrics with high quality can be prepared successfully by the above processes. The mulberry based textiles have excellent antibacterial property. The inhibitory rate of raw mulberry bark on Escherichia coli and Staphylococcus aureus is (67.2±3.1)% and (53.8±4.6)% respectively, and the inhibitory rate of mulberry fiber on Escherichia coli and Staphylococcus aureus is both above 80%. The inhibitory rate of the mulberry/cotton blended yarn on Escherichia coli and Staphylococcus aureus ranges from (51.7±5.1)% to (72.4±4.1)%, which has similar inhibitory rate with the mulberry/cotton blended fabric. The results of Fourier Transform-Infrared (FTIR) and ¹³C-nuclear magnetic resonance (¹³C-NMR) show that the typical functional group (hydroxyl, carbonyl, double bond and epoxy bond) exist in the composition of the mulberry fiber, which indicates that the flavones and phenolic compounds including in the mulberry fiber.     

Preparation and characterization of nylon-6/gelatin composite nanofibers via electrospinning for biomedical applications

Easy fabrication, porosity, good mechanical properties, and composition controllable of the electrospun nanofiber mat make this material a promising candidate for wound dressing applications. In the present study, nylon6/gelatin electrospun nanofiber mats are introduced as novel wound dressing materials. The introduced mats were synthesized by electrospinning of nylon6 and gelatin mixtures, three mats containing different gelatin content were prepared; 10, 20 and 30 wt%. Interestingly, addition of the gelatin did not affect the mechanical properties of the nylon 6, moreover the mat containing 10 wt% gelatin revealed higher mechanical properties due to formation of spider-net like structure from very thin nanofibers (～10 nm diameter) bonding the main nanofibers. Biologically study indicates that gelatin incorporation strongly enhances the bioactivity performance as increasing the gelatin content linearly increases the MC3T3-E1 cell attachment. Overall, the obtained results recommend exploiting the introduced mats as wound dressing material.     

Preparation and properties of polyvinyl alcohol/tannic acid composite film for topical treatment application

The purpose of this study was to develop an effective potential wound dressing material based on a polyvinyl alcohol (PVA) and tannic acid (TA) composite film. To prepare the PVA/TA films, PVA and TA blended aqueous solutions were cast into film form by spreading the solutions and drying them. Then the films were heat treated at 155 oC for 3 min to promote esterification between the PVA and TA. After removing un-crosslinked moieties from the films by rinsing and drying, the films were investigated by swelling behavior, FTIR spectroscopy, XRD and TGA. And, the antibacterial and antioxidant abilities of the films were also examined in this study. Through this investigation it was discovered that TA effectively acts as a functional antibacterial and antioxidant agent as well as crosslinker in the PVA/TA system. Thus, the PVA/TA composite films prepared by the casting and heat treatment method proposed in this study are expected to be used for topical medication, such as wound dressing material.     

Dyeing characteristics and UV protection property of green tea dyed cotton fabrics

There is increasing interest in the many beneficial aspects of green tea to human such as anti-carcinogenic, anti-aggregant, anti-allergic, anti-bacterial, anti-mutagenic, and anti-oxidant activities. Besides these beneficial aspects, it has been reported that green tea ingredients, especially polyphenolic families (i.e., catechin), have some UV protection property both in vivo and in topical applications. In this study, green tea extract was used as a dyeing stock for cotton and the UV protection property of the dyed cotton fabric was examined. To increase the affinity of cotton fiber to the polyphenolic components in the green tea extract, a natural biopolymer, chitosan, was used as mordanting agent. The effects of chitosan concentration in mordanting on the dyeing characteristics and the UV protection property were examined. Chitosan mordanted green tea dyed cotton showed better dyeing characteristic and higher UV protection property compared with the unmordanted green tea dyed cotton. As the chitosan concentration in mordanting increased, the dyeing efficiency and the UV protection property also increased. Therefore, adapting chitosan mordanting in green tea dyeing can increase the UV protection property of cotton fabrics to some extent.     

Preparation and properties of fumed silica/Kevlar composite fabrics for application of stab resistant material

The objective of this study is to develop an advanced stab proof material composed of shear thickening fluid (STF) and Kevlar fabric. In this study, silica/ethylene glycol suspension was prepared for the use as the STF, and it was analyzed by a rheometer, TEM and dynamic light scattering spectrophotometer. From the results, it was observed that the STF significantly showed the reversible liquid-solid transition at a certain shear rate. Also, we treated Kevlar plain fabric with the STF by 1 dip-1nip finishing method and investigated the mechanical and stab resistant properties. Through the investigation of the fumed silica/Kevlar composite fabric, we found that the STF impregnation significantly improved the stab resistance of Kevlar fabric against spike threats and so enhance the protection performance of Kevlar fabric as a stab proof material.     

Preparation and property of TiO2/SiO2 multilayer film on the fabric by sol-gel process

The high light reflection of multilayer TiO₂/SiO₂ film was prepared on the fabric by the sol-gel process. The size of titania and silica particles in hydrosol was analyzed by Nanosizer, and the morphology of TiO₂/SiO₂ multilayer film on the fabric was characterized by SEM. The reflection spectra of the samples were tested accordingly, and it showed that the reflection of the fabric coated by multilayer film was higher than that of the monolayer film. Moreover, the reflection increased with the increase of layer number. For sunlight fastness testing, the fabric color changed less with the increase of layer number, which showed the multilayer film on the fabric can improve the light resistance of the fabric. The mechanical property, the bending property and air permeability testing results showed that there was little change for the coated fabric compared with the original fabric.     

Development and evaluation of novel eucalyptus essential oil liposomes/chitosan composite sponges for medical use

Novel eucalyptus essential oil liposomes (EEOLs)/chitosan composite sponges (EC) were successfully fabricated by electrostatic self-assembly. EEOLs were prepared by the thin-membrane hydration method with sonication and blended with chitosan solution to create the sponges by lyophilization. The observations of transmission electron microscopy (TEM) and scanning electron microscopy (SEM) confirmed the existence of eucalyptus essential oil in the lipid bilayer of liposomal membrane and the location of the liposomes in positive holes formed by the protonated amino groups of chitosan. The average size of EEOLs was about 60 nm. Fourier transform infrared (FTIR) analysis showed the destroy of inter- and intramolecular hydrogen bonding among chitosan chains and the construction of the intermolecular hydrogen bonding between chitosan and molecules on the surface of EEOLs. The incorporation of EEOLs in chitosan sponges slightly decreased the porosity, fluid absorptivity, gas permeability and hemostatic property of sponges, but increased their biodegradation ability. EC exhibited more rapid and efficient microbicidal effects against Staphylococcus aureus (S. aureus), Pseudomonas aeruginosa (P. aeruginosa) and Candida albicans (C. albicans) than pure chitosan sponges. EC showed no toxicity toward human HEK293T cells and no significant adverse effect on cell attachment and proliferation of HEK293T cells. This inherent behaviour can be exploited to apply in the medical field.     

高吸附性甜菜纤维的制备和性能研究

本文报道一种离子吸附性甜菜纤维的制备方法及其离子交换性能。将甜菜糖厂副产物甜菜渣,常温下用2%～4%的氢氧化钠处理48h,可获得高吸附性甜菜纤维,其中金属离子交换容量可达0.65～1.05mmol/g。用以处理含重金属离子水表明,吸附率可达60%～85%。