Nonwoven Surface Research Articles

Development of novel nanocomposite adsorbent based on potassium nickel hexacyanoferrate-loaded polypropylene fabric.

A nanocomposite adsorbent based on potassium nickel hexacyanoferrate-loaded polypropylene fabric was synthesized for selective removal of Cs ions from contaminated waters by a two-stage synthesis: radiation-induced graft polymerization of acrylic acid monomer onto the nonwoven polypropylene fabric surface with subsequent in situ formation of potassium nickel hexacyanoferrate (KNiHCF) nanoparticles within the grafted chains. Data of scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy confirmed the formation of KNiHCF homogeneous phase on the fabric surface, which consisted of crystalline cubic-shaped nanoparticles (70 to 100 nm). The efficiency of the synthesized adsorbent for removal of cesium ions was evaluated under various experimental conditions. It has demonstrated a rapid adsorption process, high adsorption capacity over a wide pH range, and selectivity in Cs ion removal from model solutions with high concentration of sodium ions.

Microwave-Assisted Synthesis of Tin Dioxide Nanocrystals on the Surface of Polypropylene Melt-Blown Nonwovens

Nanocrystals of stable, tetragonal tin dioxide have been synthesized using microwave processing, and the effect of microwave heating on the structural phase transformations of the tin compounds involved has been examined. The results are used to determine microwave heating parameters that ensure strong bonding of nanocrystals to the surface of polypropylene nonwoven.

Influence of Wire Grid on the Cone Calorimeter Results of Textile Fabrics

In this article, an improved procedure based on ISO 5660-1 and ASTM E1474 was developed to ensure the effectiveness and reliability of cone calorimeter test of textile fabrics. In order to improve the instability for some easy shrinking fabrics exposed under heat in cone calorimeter test, an iron wire grid was applied to cover the top surface of polypropylene nonwovens and polyester fabrics to avoid drastic distortion caused by heating irritation. Results showed that the iron wire grid could avoid the distortion of the easy shrinking samples and stable test process, also success probability and results repeatability were also improved. A guiding effect was found during the test caused by the grid, which leaded to a better uniformity of polymer melt under the thermal or even on fire.

Plasma activation and acrylic acid grafting on polypropylene nonwoven surface for the removal of cationic dye from aqueous media

In this paper, the preparation, characterization and cationic dye adsorption properties of acrylic acid-grafted polypropylene nonwoven (AA-PP) using plasma as a surface activation pretreatment were investigated. Surface characteristics of AA-PP were studied using attenuated total reflection–Fourier transform infrared spectroscopy and scanning electron microscopy. Methylene blue was used as a model dye. The effects of operational parameters such as AA-PP dosage, initial dye concentration, and pH on dye removal were evaluated. The isotherm and kinetics of dye adsorption were also studied. The data were evaluated for compliance with the Langmuir, Freundlich, and Temkin isotherm models. It was found that the dye adsorption followed Freundlich isotherm. The rates of sorption were found to conform to pseudo-first-order kinetics with good correlation. Results indicated that AA-PP could be used as a cheap, long–lasting, and more environmentally friendly sorbent to remove cationic organics from contaminated water, compared to other adsorbents.

Multi-functional Polyester Hollow Fiber Nonwoven Fabric with Using Nano Clay/Nano TiO2/Polysiloxane Composites

Surface modification and property improvement of hollow polyester fiber nonwoven fabric is very important due to the application of substrate in the various fields. Here, nano clay, nano TiO2 and polysiloxane softener as been applied on the hollow polyester fiber nonwoven fabric through conventional impregnation-dry-cure method in order to enhance the fabric properties. The alkaline hydrolysis of polyester was performed on the nonwoven surface to functionalize the fabric and increase the nanoparticles uptake. The nano clay was first dispersed by using nonionic dispersing agent, and then nano titanium dioxide dispersion was added dropwise to the prepared nano clay dispersion. Also, other dispersions were prepared with adding polysiloxane softener and polyurethane resin under sonication. The SEM images and EDX/XRD patterns indicated the presence of various applied particles on the surface of the fabric. Thermal gravimetric analysis was employed to investigate the thermal decomposition behavior of the treated samples. Self-cleaning properties of polyester nonwoven treated by TiO2/nano clay/polysiloxane composite was followed by degradation of methylene blue under daylight irradiation at ambient temperature. It was found that nano clay/TiO2/polysiloxane composite on the fabric surfaces improved self-cleaning property, thermal stability above 400 °C, and water absorption properties of the fabric.

Evaluation of polypropylene and poly (butylmethacrylate-co-hydroxyethylmethacrylate) nonwoven material as oil absorbent

Polypropylene (PP) and poly(butylmethacrylate-co-hydroxyethylmethacrylate) (PBMA-co-HEMA) nonwoven materials as oil absorbents have been fabricated for the first time via melt blown method. As-prepared nonwovens were investigated in terms of mass per unit area, density, air permeability, contact angle, and morphology observations for fiber diameter distribution and single fiber surface by a field emission scanning electron microscope. The nonwovens are demonstrated as fast and efficient absorbents for various kinds of oils with oil absorbency up to seven to ten times their own weight. The nonwovens show excellent water repulsion but superoleophilic properties. The measured contact angles for water and toluene are more than 127° and ca. 0°, respectively. The addition of PBMA-co-HEMA makes the nonwoven surface more hydrophobic while conserving superoleophilicity. Compared with PP nonwoven, broad diameter distribution of the blend nonwoven is attributed to poor melt fluidity of PBMA-co-HEMA. In terms of single fiber, coarse surface and the presence of point-like convexities lead to the fibers being more readily wetted by oil. More interesting, oil-water separation and oil recovery can be easily carried out by filter and absorption-desorption process, the recovered materials contained hardly any oil droplet and could be reused for next cycles.

Deposition of Gold Nanoparticles on Polypropylene Nonwoven Pretreated by Dielectric Barrier Discharge and Diffuse Coplanar Surface Barrier Discharge

The aim of this study was to examine and compare the potentials of two different ambient air plasma treatments: volume dielectric barrier discharge and diffuse coplanar surface barrier discharge, for the activation of polypropylene (PP) nonwovens surface. This was done in order to enhance the deposition of gold nanoparticles (AuNPs) onto PP surface. AuNPs were attached onto PP surface from colloidal solution prepared without stabilizers. Scanning electron microscopy, atomic force microscopy, attenuated total reflection-Fourier transform infrared spectroscopy, water absorption, and AuNPs uptake were used to assess the surface changes due to the plasma treatment, and to evaluate the durability of the achieved treatment effects. Finally, as a very important aspiration of the research, antibacterial activity of AuNPs loaded PP nonwovens against pathogens Staphylococcus aureus and Escherichia coli was evaluated in vitro. The plasma modified PP nonwovens have highly improved wetting and sorption properties. The PP nonwovens loaded with 17–62 mg/kg AuNPs exhibit antibacterial activity against tested pathogens. Surprisingly, this activity was enhanced by the first sample rinsing.

Utilization of Recycled Polypropylene-Acrylate Grafted Nonwoven for the Removal of Oil from Water

To solve water pollution caused by oil spillage, a new sorbent was prepared by radiation-induced graft polymerization. Acrylate monomer was introduced to polypropylene nonwoven and hydrophobic groups were introduced by the grafting method. The grafting degree of sorbent was determined as a function of monomer concentration and solvent solubility for monomer. Fourier transform-infrared spectra and static contact angle measurements were used to characterize the chemical changes of the polypropylene nonwoven surface. The grafted sorbent showed a fast sorption rate and a maximum sorption capacity of 13.56 g/g for diesel oil, while the original polypropylene nonwoven was only 7.48 g/g. In addition, retention measurement and the reusability test were conducted to evaluate the suitability of the polypropylene-acrylate grafted nonwoven for the treatment of oil spillage.

Characteristics of flux and gel layer on microfilter and non-woven fabric filter surface based on anoxic–aerobic MBRs

Non-woven fabric filter- (NWFF) and microfilter-MBR modules were made using 100μm polypropylene and 0.25μm polyethylene materials, respectively. The performances and mechanisms of the two processes were investigated, including additional batch filtration tests to find the function of the dynamic gel layer on the membrane surface. The HRT of both MBRs was 9h and the operating permeate flux was 13L/m(2)/h. The two MBRs consisted of an anoxic and aerobic reactor. The NWFF or microfilter (MF) was submerged in each of the aerobic reactors. The two MBRs showed similar performances for the removal of organic matters, suspended solids and nitrogen. Cake formation on the NWFF contributed to major resistance, while the gel layer on the microfilter or internal fouling of the pores played a key role in the fouling of the membrane surface. The amount of soluble extracellular polymer substances (EPS) (13mg/L) of the attached sludge on the NWFF surface was larger than that (11mg/L) of that suspended sludge. Consequently, the functional gel layer for the coarse and microfilter is established based on the relationship among the EPS, transmembrane pressure and MLSS.

Generation of Functional Coatings on Hydrophobic Surfaces through Deposition of Denatured Proteins Followed by Grafting from Polymerization

Hydrophilic coatings were produced on flat hydrophobic substrates featuring n-octadecyltrichlorosilane (ODTS) and synthetic polypropylene (PP) nonwoven surfaces through the adsorption of denatured proteins. Specifically, physisorption from aqueous solutions of α-lactalbumin, lysozyme, fibrinogen, and two soy globulin proteins (glycinin and β-conglycinin) after chemical (urea) and thermal denaturation endowed the hydrophobic surfaces with amino and hydroxyl functionalities, yielding enhanced wettability. Proteins adsorbed strongly onto ODTS and PP through nonspecific interactions. The thickness of adsorbed heat-denatured proteins was adjusted by varying the pH, protein concentration in solution, and adsorption time. In addition, the stability of the immobilized protein layer was improved significantly after interfacial cross-linking with glutaraldehyde in the presence of sodium borohydride. The amino and hydroxyl groups present on the protein-modified surfaces served as reactive sites for the attachment of polymerization initiators from which polymer brushes were grown by surface-initiated atom-transfer radical polymerization of 2-hydroxyethyl methacrylate. Protein denaturation and adsorption as well as the grafting of polymeric brushes were characterized by circular dichroism, ellipsometry, contact angle, and Fourier transform infrared spectroscopy in the attenuated total reflection mode.

Statically non-wetting electrospun perfluorocyclobutyl (PFCB) aryl ether polymer doped with room temperature ionic liquid (RTIL)

A statically non-wetting, electrospun surface of non volatile room temperature ionic liquid (RTIL), 1-butyl-3-methylimidazolium hexafluorophosphate, (BMIM-PF6), hosted in a solution-processable, semi-fluorinated perfluorocyclobutyl (BP-PFCB) aryl ether polymer was successfully prepared by electrospinning and compared with a surface prepared by spin casting. The surface properties of undoped and BMIM-PF6 doped systems were analyzed by water contact angle (WCA) and atomic force microscopy (AFM). BMIM-PF6 doped BP-PFCB surfaces prepared by spin casting showed a WCA of 90° while non-woven electrospun surfaces with the same BMIM-PF6 concentration showed high degree of hydrophobicity with a WCA greater than 150°. Morphologies of the electrospun surfaces were characterized by scanning electron microscopy (SEM). The surface composition was analyzed by energy-dispersive X-ray spectroscopy (EDXS) and attenuated total reflectance infrared spectroscopy (ATR-IR). Thermal analysis of the electrospun, non-woven surfaces of the doped and the undoped system of BP-PFCB were done by TGA.

Preparation and Photocatalytic Activity of -Deposited Fabrics

Nanoscale titanium dioxide (TiO2) photocatalytic films were deposited on the surface of polyester nonwovens by using direct current reactive magnetron sputtering. The effects of coating thickness on the surface structures and properties of TiO2-coated fabrics were investigated by X-ray photoelectron spectroscopy (XPS), atomic force microscope (AFM), and scanning electron microscope (SEM). The photocatalytic activity of the functional nonwoven fabrics was evaluated by the degradation of methylene blue. The test results proved that the grain sizes of the sputtered clusters increased and the coating layer became more compact with the increase of film thickness, but the composition of the sputtered films did not have any significant change. At the same time, the photocatalytic activity of TiO2-coated fabrics mostly depended on the film thickness which could lead to the optimum thickness for a particular application.

Polypeptide multilayer self-assembly and enzymatic degradation on tailored gold surfaces studied by QCM-D

This study deals with the build up and enzymatic degradation of a nanofilm made by the layer-by-layer (LbL) self-assembly technique on a surface that mimics nonwoven, which is commonly used in wound dressings. The nanofilm is composed of alternating layers of the cationic polyelectrolyte poly-L-lysine (PLL) and the anionic polyelectrolyte poly-L-glutamic acid (PLGA) and is intended as a lid for bactericides inserted into a dressing for chronic wounds. Chronic wounds are often infected by bacteria such as Staphylococcus aureus and a mechanism to trigger release of bactericides into such wounds when they become infected is of interest. QCM-D (quartz crystal microbalance with dissipation monitoring) was used to monitor both build-up and degradation of the nanofilm on a surface tailored by the self-assembly monolayer technique to resemble the nonwoven surface. It was found that whereas a normal protease present in the body and wound, as well as a bovine protease that was used as reference, did not catalyze degradation of the polyelectrolyte multilayer, a protease from Staphylococcus aureus, V8 glutamyl endopeptidase, caused rapid break-down of the film. However, a prerequisite of the degradation was that the LbL assembly had been terminated by the anionic PLGA. The results open for products where the wound infection is the trigger for release of bioactive substances from a wound dressing.

Characterization of nonwoven poly(ethylene terephtalate) devices functionalized with cationic polymer

AbstractA cationic functionalization was carried out on poly(ethylene terephtalate) (PET) nonwovens by the method of padding with a solution of polymer (P1 and Px). An atmospheric pressure plasma treatment was prior used to improve the hydrophilic property of the nonwoven surface before the functionalization with cationic agents. The zeta potential measurements of the nonwovens, based on streaming potential, show the presence of cationic groups at the PET surface depending on the pH value. The analysis of washing water showed that the PET nonwoven functionalized with cationic polymer Px needed more washing cycles than with polymer P1, to remove all the species non fixed at the surface. The cytotoxicity tests show that both of ammonium polymers are toxic toward endothelial cells. This means that it leaves many active chemicals on the surface of the functionalized materials, even after washing. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Comparison of three methods for generating superhydrophobic, superoleophobic nylon nonwoven surfaces

This research deals with creating a superhydrophobic/superoleophobic surface by preparing a metastable Cassie–Baxter (CB) surface. To create a CB surface it is essential to have low surface energy and properly constructed surface morphology. We have explored three different techniques to achieve superhydrophobicity and superoleophobicity using hydroentangled nylon nonwoven fabric: pulsed plasma polymerization of 1H,1H,2H,2H-perfluorodecyl acrylate (PFAC8), microwave-assisted condensation of 1H,1H,2H,2H-perfluorodecyltrimethoxysilane (FS), and FS condensation through wet processing. Nonwoven fabric materials prepared using these three techniques were superhydrophobic and superoleophobic as shown by their very high contact angles for both water (contact angles of 168–174°) and dodecane (contact angles of 153–160°). The measured contact angles agree with the predicted values obtained through designing a CB surface.

Selective Deposition of Electrospun Alginate-Based Nanofibers onto Cell-Repelling Hydrogel Surfaces for Cell-Based Microarrays

This paper proposes selective deposition of electrospun alginate-based nanofibers through a charged shadow mask to form an array of nonwoven microspots on cell-repelling hydrogel surfaces; subsequently, the target cells are seeded onto these nanofiber-based extracellular matrix (ECM) scaffolds to create cell-based microarrays. The needle tip contains a drop of a blended solution of alginate and polyethylene oxide (PEO); an Al-coated glass shadow mask with micron-sized holes was used for selective deposition to form the patterned microspots of nonwoven mats. The shadow mask was applied with a suitable voltage to repel the nanofibers from its surface, while simultaneously forcing them into the micron-sized holes and onto the cell-repelling hydrogel surface. The electric-field distribution of the electrostatic focusing through the charged shadow masks was numerically simulated and characterized. The experimental results show that when the shadow mask is applied with a higher voltage, a larger dense central spot will be produced within the hole; in addition, the diameter is significantly reduced but the degree of diameter uniformity among the electrospun nanofibers improves. An array of 3 × 3 nonwoven microspots was successfully demonstrated to selectively deposit alginate-based nanofibers for cell patterning. BHK-21 fibroblast cells were shown to selectively adhere onto the nonwoven microspot surfaces due to the existence of the cell-repelling hydrogel around the microspots. The presented technique is simple and does not require complex surface modifications to selectively seed the target cells onto these micron-sized nanofiber-based ECM scaffolds for potential applications in cell biology and tissue engineering. Keywords: Electrospinning, electrostatic focusing, nanofiber, cell patterning, nonwoven microspots, shadow mask, cell-repelling

An investigator blinded cross-over study to characterize the cutaneous effects and suitability of modern sanitary pads for menstrual protection for women residing in the USA

Background: The cutaneous and sensory effects of the practical usage of sanitary pads have been studied globally. However, clinical studies in the United States were conducted only quite a long time ago, and the results of these studies were not published.Methods: Fifty-four women residing in the United States were asked to use commercially available sanitary pads with a nonwoven unique surface sheet and pads with a perforated film. This was a cross-over study design conducted over the course of two menstrual periods. A board certified dermatologist evaluated the levels of erythema and fissuring, burning, stinging and itching sensations based on clinical observations and interviews. Measurement of pH and swabs for bacteria counting of vulvar skin were also performed. Data from the first clinical evaluation conducted prior to the first menstrual cycle were used as the baseline. At the end of the study, the subjects were asked to complete self-assessment questionnaires about product suitability.Results: Forty-two women (age: 18–50, mean: 37.5) completed the study. No signs of irritation or meaningful differences from the baseline were found in the clinical observations or in the interviews by the dermatologist for either product. No significant difference from baseline was found in the vulvar skin surface pH or in the number of total bacteria for either product. The results of the suitability indicated that the majority of subjects were highly satisfied with both types, but they especially preferred the sanitary pad with a nonwoven unique surface top sheet.Conclusion: These results revalidate the results of a previous clinical study in the United States and are consistent with recent reports of worldwide clinical trials of high performance sanitary pads.

Cutaneous and sensory effects of two types of sanitary pads with different surfaces in the Shanghai, Chinese population

Background: Regional differences in practices, ethnicity, and climate may influence the skin compatibility of sanitary pads. Although several clinical trials have been performed in North America, Mexico, Western Europe, Eastern Europe, and Africa, there is no clinical study reported for Asia.Objective: The purpose of this study was to examine the skin compatibility of two types of modern sanitary pads in Chinese women along with a dermatological assessment and their satisfaction and preference.Materials and methods: The self-feeling and safety of a new sanitary pad with a non-woven top specially-shaped surface sheet was tested and compared with a conventional sanitary pad with a perforated film top sheet. The subjects studied were 22 Chinese women (age: 20–50 years) with a history of mild and occasional sanitary pad dermatitis residing in Shanghai. One subject wished to discontinue the trial for personal reasons, thus 21 subjects completed the trial. These subjects were randomly assigned to two types of sanitary pads, and used one type during their next menstrual period, and another type during their following menstrual period. After each menstrual period, a dermatologist examined the objective and subjective skin symptoms and determined a score. The subjects were asked to rate their level of satisfaction with respect to overall usability, softness, stickiness, dryness, and absorbency, and to choose which pad they had preferred.Results: No adverse effect was observed for either type of pad. Edema, erythema, burning, and stinging were not obvious symptoms for either type of pad. For itching, 30–65% of the subjects scored slight or mild for both types of pads. A comprehensive evaluation showed that several symptoms were observed on both type of pads at slight and mild levels, but minimal and insignificant differences were found between them. The majority of subjects were highly satisfied with both types, but preferred the new sanitary pad with a non-woven specially-shaped surface top sheet for its softness and absorbency.Conclusion: Our results indicate that both types of sanitary pads were tolerated well by Chinese women, thereby providing an important extension of earlier studies.

Surface Wettability of Polypropylene Non-Woven Using Atmospheric Pressure N<sub>2</sub> Dielectric Barrier Discharge Plasma

In this thesis, the atmospheric pressure nitrogen dielectric barrier discharge (DBD) plasma modified polyproylene (PP) melt blown non-woven surface wettability are investigated. The change of surfaces physical and chemical properties are studied by water contact angle measurement and X-ray photoelectron spectroscopy (XPS) before and after plasma treatment. The experimental results indicate the surface hydrophilic can be greatly improved when the PP simples is treated by atmospheric pressure nitrogen DBD plasma for a short time. And a large number of oxygen-containing and nitrogen-containing functional groups are inplanted on the PP non-woven sample surface.

Polypropylene nonwoven fabrics with conformal grafting of poly(glycidyl methacrylate) for bioseparations

Nonwovens fabrics are porous materials with great potential for use in the separation and purification of biotherapeutic proteins and other biomolecules after proper surface activation and modification. This work describes an activation process for polypropylene nonwoven membranes by conformal coating of poly(glycidyl methacrylate) (polyGMA) through a UV pretreatment–UV grafting process (UV–UV) in the presence of benzophenone as initiator. The grafting mechanism relies on the enhanced adsorption of benzophenone to the fiber surface after the UV pretreatment. It was found that this process results in highly conformal and uniform polyGMA grafts on the surface of the PP nonwoven fibers. After grafting, a hydrophilic spacer, diethylene glycol, an anion exchange ligand, diethyl amine, and a combination of diethylene glycol spacer-primary amine were attached to the PP nonwoven surface with the conformal polyGMA grafts. High equilibrium protein binding capacities for bovine serum albumin (BSA) under static and flow conditions were obtained (120 mg/g and 102 mg/g, respectively). A column packed with modified nonwovens exhibited higher permeability coefficient (1.08 × 10 −7 cm 2) than columns packed with chromatographic resins. The total porosity (to acetone) was found to be 0.80 and the interstitial porosity (to BSA) was 0.48, measured by pulse experiments using acetone and BSA respectively as tracers under nonbinding conditions.