Kyung Hwa Hong

Preparation and properties of multi-functionalized cotton fabrics treated by extracts of gromwell and gallnut

Extracts from the root of Lithospermum erythrorhizon (gromwell) have been used for many centuries as a natural red dye and crude drugs with excellent performance for wound healing. In particular, shikonin a major constituent of the gromwell colorant is reported to possess antibacterial, antioxidant, anti-inflammatory, antitumor activities, etc. Therefore, we tried to manufacture antimicrobial and antioxidant cotton fabrics for biocompatible clothing materials using the natural stuff and environmentally friendly process. In this study, cotton fabrics were dyed with the colorant extracted from the root of gromwell, and their properties were closely investigated. Consequently, we discovered that the cotton fabrics dyed with the extracts from the root of gromwell showed excellent antioxidant performance as well as antibacterial ability. Also, the functionalities and color fastness were improved by gallnut mordanting and cationization of the cotton fabrics.

Photo-induced antimicrobial and decontaminating agents: recent progresses in polymer and textile applications

In recent years, antimicrobial and decontaminating products and materials have drawn a lot of attention due to the outbreaks of infectious diseases in the public, as well as potential and unwanted exposure to certain hazardous chemicals in the living environment. Photo-chemistry has revealed that both inorganic photo-catalysts and organic photo-sensitizers could generate some reactive oxygen species (ROSs) on certain polymeric surfaces under light exposure and these ROS can provide antimicrobial and decontaminating functions. Thus, researchers have been trying to incorporate the photo-active agents into various polymeric substrates to prepare self-decontaminating materials for medical applications, protective clothing, etc. This paper will provide a review of the recent research progresses in the area of photo-induced functional materials, specifically antimicrobial functions and decontamination abilities of the materials.

Surface Roughness Measurement of Nonwovens Using Three-dimensional Profile Data

The surface friction property changes of nonwovens under repetitive abrasions were observed. Surface data were acquired using a three-dimensional noncontact camera and fractal dimensions were calculated to evaluate surface roughness. The fractal dimension showed a tendency to increase with the number of abrasions. They were compared with surface friction values measured by the KES-FB system [Textile Res. J. 58(3), 129—136, 1988]. Pilling on the nonwoven surface prohibited accurate surface roughness measurement, so they were detected using high-pass filtering of the surface data. The method needs instant measurement time and is highly objective, and therefore it is suitable for real-time on-line manufacturing systems.

Effect of Abrasion and Absorbed Water on the Handle of Nonwovens for Disposable Diapers

Among the components of a disposable diaper, the top layer that comes into direct contact with the infant’s skin is usually made of a nonwoven fabric. Therefore, the mechanical and surface characteristics of the nonwovens are important for the health of the baby’s skin. In this study, we explored the mechanical and surface properties of some hygienic nonwoven fabrics that are used as the top layer and investigated consumers’ preferences concerning these nonwovens. The variations in their properties with increasing abrasion cycles and in wet conditions were also examined. The hygienic nonwoven fabrics examined in this study were cotton spunlace, tencel spunlace, polypropylene (PP) thermal bonding and PP Thru-air bonded carded web (TABCW). The surface of PP nonwoven fabrics were treated with surfactant to obtain the required hydrophilic properties. From the results of KES-F analysis, it was found that PP TABCW had a low friction coefficient and showed little change in surface properties with increasing number of abrasive cycles, and moreover, it revealed superior quick-drying characteristics. However, the consumers showed a somewhat higher preference for cellulose spunlaces in comparison with surfactant-treated PP nonwoven fabrics. On the other hand, although they showed excellent absorption characteristics, the spunlace-type nonwovens made with cellulose tissue displayed higher surface friction coefficients and relatively low abrasion strength, especially in wet conditions.

Thermal Stability of Conductive Polyaniline-Nylon 6 Composite Fabrics Doped by a Mixture of Protonic Acids:

We have studied the thermal stability of conductive polyaniline (PANI)-nylon 6 composite fabrics doped by a mixture of hydrochloric acid (HCl) and various organic aryl sulfonic acids such as benzenesulfonic acid (BSA), dodecylbenzenesulfonic acid (DBSA), and ρ-toluenesulfonic acid (TSA). Conductive fabrics are prepared by immersing the nylon 6 fabrics in an aqueous hydrochloride solution of 0.5M aniline and by initiating successive polymerization with an oxidant in various doping solutions. When the same molar ratio of HC1 in the diffusion bath and various protonic acids in the polymerization bath are mixed and serve as the dopant for polyaniline, the highest fabric conductivity is obtained with HC1/BSA, and HC1/TSA, HC1/DBSA, and HC1/HC1 in decreasing order. The conductivity of all doped PANI-nylon 6 composite fabrics decays at elevated temperatures in air. Among the various dopants, HC1/DBSA shows the best thermal stability, followed by HC1/TSA > HC1/BSA > HC1 in decreasing order.

Preparation and properties of cotton and wool fabrics dyed by black rice extract

Black rice is known as a health-promoting food for its abundant content of anthocyanins. Anthocyanins possess various functionalities, such as antioxidant, antibacterial, anti-tumor, and anti-inflammatory effects. However, they are easily wasted during the cooking process since they are water soluble pigments. Thus, the aim of this study was to use the black rice extract produced from the cooking process as a natural pigment and functional agent for textile finishing. In this study, wool and cotton fabrics were dyed by the black rice extract and the dyed fabrics were investigated by various analyzers. For cotton fabric, cationization was conducted before the dyeing process. The results revealed that wool and cotton fabrics were colored in reddish brown through the dyeing process. In addition, the wool and cotton fabrics dyed by black rice extract showed superior colorfastness in drycleaning and washing conditions compared to fabrics dyed by other natural pigments. In particular, the wool and cotton fabrics dyed by black rice extract possessed antibacterial and antioxidant characteristics. It was further observed that the functionality was increased by repeating the dyeing process.

Functional fabric treatment using tannic acid and extract from purple-fleshed sweet potato

Purple-fleshed sweet potato (PSP) has a reddish purple color with high amounts of anthocyanins and phenolic acids, both of which have various health-promoting effects. The acylated anthocyanins present in PSP are more heat-resistant than the nonacylated types found in other plants. Therefore, PSP extract was considered as a natural pigment and functional agent for textile dyeing and/or finishing processes. Here, wool and cotton fabrics are pretreated by a tannic acid aqueous solution to increase their dyeability and then dyed by PSP extract. The dyed fabrics are then investigated by various analysis techniques. The results revealed that wool and cotton fabrics can be dyed bluish red through the pretreatment and dyeing process. The wool and cotton fabrics also showed antibacterial and antioxidant characteristics.

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.

Preparation and properties of multifunctional cotton fabrics treated by phenolic acids

Abstract Phenolic acids are found in many plant-based natural antioxidants and are known to offer diverse health-promoting effects such as antimelanogenic, antioxidant, antineoplastic, and bacteriostatic properties. Furthermore, they not only inhibit pathogen growth but also have little toxicity to human beings. Therefore, in this study we treated cotton fabrics with two different phenolic acids, gallic acid (GA) and 4-hydroxybenzoic acid (4-HBA), through a pad-dry cure process, and investigated the properties such as mechanical properties, antibacterial ability, antioxidant ability, etc. Consequently, the phenolic acid treatment did not have significant influence on color, touch, and tensile strength of cotton fabrics. However, it was found that the cotton fabrics treated by both GA and 4-HBA showed high antibacterial ability against Staphylococcus aureus and Klebsiella pneumonia; however, only the GA treated cotton fabrics showed reasonable antioxidant ability.

Preparation and properties of multi-functional cotton fabric treated by gallnut extract

Aqueous extract of gallnut is well known to have remarkable antioxidant and antibacterial activities. Gallnut is expected to be a safe antibacterial agent for textile application because it is a non-toxic natural substance. Thus, we applied gallnut extract to cotton fabrics using an infrared dyeing machine and a pad-dry-cure process, in order to develop multi-functional clothing material with no harmful side effect. Through this study, we found the optimum condition (via a pad-dry-cure process at 120℃/15 min) for the gallnut extract treatment of cotton fabrics. The surface appearance, mechanical properties, antibacterial ability, and antioxidant performance of the treated cotton fabrics were thoroughly investigated. Consequently, it was found that antibacterial and antioxidant cotton fabrics were obtained via the gallnut extract treatment.