Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Heliyon ; 9(6): e16434, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37260882

RESUMEN

Plastic, in all its forms, always harms the environment, humans, and other living organisms. The coronavirus situation exacerbates the use of plastic products more than at any other time, of which surgical masks contribute to plastic pollution the most. These masks spread to terrestrial and aquatic environments, where they break down into even more noxious microplastics. These microplastics enter the human food chain through water and fish, causing severe damage to the lungs, kidneys, and intestines and even causing death. In this paper, a jute nose holder mask was prepared as an alternative to typical masks to reduce plastic pollution. The jute nose holder was produced with a modified jute flyer-spinning frame machine, where jute was used as the sheath and metal wire was applied as the core component. The nose holder was later coated with starch-based natural gum. Then, the non-woven fabric of 75 grams per square meter (GSM), and the jute nose holder were used to produce the alternative, environmentally friendly mask, which might reduce the 773 tons of plastic waste generated daily from the nose holder of the mask. This alternative mask was then distributed to 900 people for a survey to find out their opinion. From the results of the survey, it is seen that 82.6% of people felt no problem in the nose when they put on the given mask. 85.6% considered the mask more comfortable than the traditional mask, and it was rated above average by 79.8% of the surveyors. So, this study suggests that the given mask can be a sustainable alternative to traditional masks.

2.
Langmuir ; 39(13): 4557-4570, 2023 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-36947877

RESUMEN

Polymers containing poly(ethylene glycol) (PEG) units can exhibit excellent antifouling properties, which have been proposed/used for coating of biomedical implants, separation membranes, and structures in marine environments, as well as active ingredients in detergent formulations to avoid soil redepositioning in textile laundry. This study aimed to elucidate the molecular behavior of a copolymer poly(MMA-co-MPEGMA) containing antiadhesive PEG side chains and a backbone of poly(methyl methacrylate), at a buried polymer/solution interface. Polyethylene terephthalate (PET) was used as a substrate to model polyester textile surfaces. Sum frequency generation (SFG) vibrational spectroscopy was applied to examine the interfacial behavior of the copolymer at PET/solution interfaces in situ and in real time. Complementarily, copolymer adsorption on PET and subsequent antiadhesion against protein foulants were probed by quartz-crystal microbalance experiments with dissipation monitoring (QCM-D). Both applied techniques show that poly(MMA-co-MPEGMA) adsorbs significantly to the PET/solution interface at bulk polymer solution concentrations as low as 2 ppm, while saturation of the surface was reached at 20 ppm. The hydrophobic MMA segments provide an anchor for the copolymer to bind onto PET in an ordered way, while the pendant PEG segments are more disordered but contain ordered interfacial water. In the presence of considerable amounts of dissolved surfactants, poly(MMA-co-MPEGMA) could still effectively adsorb on the PET surface and remained stable at the surface upon washing with hot and cold water or surfactant solution. In addition, it was found that adsorbed poly(MMA-co-MPEGMA) provided the PET surface with antiadhesive properties and could prevent protein deposition, highlighting the superior surface affinity and antifouling performance of the copolymer. The results obtained in this work demonstrate that amphiphilic copolymers containing PMMA anchors and PEG side chains can be used in detergent formulations to modify polyester surfaces during laundry and reduce deposition of proteins (and likely also other soils) on the textile.

3.
Heliyon ; 9(1): e13096, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36747950

RESUMEN

This study aims to maximize yarn realization by minimizing hard waste generation. A new method has been evaluated in a conventional carding machine for this purpose by adding extra air suction units immediately above the doffer and in the brush roller above the stripping roller. Various yarn samples were spun using the double air suction carding (DASC) method and the traditional carding process, and the yarn quality parameters were compared. The results indicated that the DASC yarn had considerable technical improvements in all yarn characteristics (U%, CVm%, thick place, thin place, neps, hairiness) and mechanical properties (breaking strength and elongation). The number of classimat faults in the DASC yarn has also significantly decreased. Even though the DASC technique produced more droppings-1, it generated less pneumafil and hard waste, resulting in improved yarn realization. This research also examined cost analysis, advantages, and limitations. Overall, the findings indicate that the newly introduced DASC yarn has the potential to be a superior product in terms of both quality and cost.

4.
J Phys Chem Lett ; 11(22): 9901-9906, 2020 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-33170701

RESUMEN

Understanding interfacial phenomena is important in processes like corrosion, catalysis, and electrochemical reactions. Specifically, in corrosion inhibition, the assembly of adsorbed surfactants at metal-water interfaces in well-packed, ordered layers is desired. We provide direct evidence of the role of alkyl tails of surfactants in the formation of ordered adsorbed layers at metal-water interfaces. We have employed surface-specific sum frequency generation (SFG) spectroscopy to probe the in situ adsorption and self-assembly of cationic surfactants, alkyldimethylbenzyl ammonium bromides of tail lengths n = 4 (C4) and 12 (C12), without any applied potential or stimulus, at the gold-water interface. Our SFG measurements show that C12 Quat adsorbs as an ordered monolayer, whereas C4 Quat adsorbs in a disordered monolayer. All-atom molecular dynamics (MD) simulations of these surfactants corroborate with SFG results. These findings provide new insights on how hydrophobic interactions between alkyl tails of surfactants affect their self-assembly at metal-water interfaces.

5.
J Colloid Interface Sci ; 568: 221-233, 2020 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-32088452

RESUMEN

HYPOTHESIS: Surfactants are commonly used as corrosion inhibitors for oil-and-gas pipelines. The alkyl chain of surfactants and their overall conformation contributes to the adsorption, flotation, and foam separation in the inhibition process. We hypothesize that the conformation of shorter alkyl chains and chemical nature of surfactants has an effect on the ordering of water molecules at the air-water interface which is not yet well understood. EXPERIMENTS: Alkyl (C4, C6, C8, C10, and C12) dimethylbenzylammonium bromides (Quats) were synthesized. Aqueous solutions at 0% and with different salt concentrations were studied at the air-liquid interface using sum frequency generation spectroscopy. Surface tension and pH measurement were also conducted for comparison. FINDINGS: Surfactant solutions at 0%, 1%, and 10% salt showed a zigzag trend for the number of gauche defects. At 0% salt, an increasing trend of OH band intensity at 3182 cm-1 was observed from C6 to C12 SFG spectra. Yet, C4 showed a more prominent SFG signal from strongly hydrogen-bonded water molecules compared to C6. The headgroup's chemical nature was found to play a role in the ordering of water molecules for a C4 alkyl chain length. The OH band intensity decreases with increasing ionic strength.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...