Oblikovanje pH odzivnega tekstilnega senzorja za pralne plenice

Jerebic, Špela (author), Kert, Mateja (mentor)

Izdelava pametnih tekstilij, med katere uvrščamo tudi halokromne tekstilije oziroma tekstilije, barvno odzivne na spremembo vrednosti pH, iz leta v leto narašča. Otroške plenice za enkratno uporabo zaradi prisotnega indikatorskega barvila lahko uvrščamo med pasivne tekstilne materiale, saj indikatorsko barvilo v plenici spremeni barvo, ko je plenica omočena z urinom in tako vizualno opozori, da je treba otroku zamenjati plenico. Indikatorskega barvila, ki ga tržijo kot barvilo za beleženje vlažnosti otroške plenice, nismo zasledili v otroških plenicah za večkratno uporabo, zato je bila v okviru magistrskega dela oblikovana halokromna tekstilija iz pletiva PA 6,6, primerna za izdelavo pralne plenice. Barvilo bromofenol modro (BPB) je bilo naneseno na pletivo PA 6,6 z direktnim tiskom s tehniko ploskega filmskega tiska. Barva in barvna odzivnost tekstilije na spremembe vrednosti pH sta bili spektrofotometrično ovrednoteni pred potopitvijo potiskanih vzorcev v pufrske raztopine različnih vrednosti pH in po potopitvi. Barvne obstojnosti potiskanega pletiva pri pranju, ob drgnjenju in na svetlobi so bile izvedene v skladu z veljavnimi standardi SIST EN ISO. Rezultati raziskave so pokazali, da je BPB odlično barvno odzivno v pufrskih raztopinah, medtem ko je barvna odzivnost barvila BPB, vezanega na pletivo PA 6,6, veliko slabša. Slednje smo pripisali vezanju barvila na vlakna in jakostim interakcij barvilo-vlakno, ki otežujejo protonacijo in deprotonacijo barvila. Pletivo PA 6,6 je dobro barvno obstojno na pranje pri 60 °C in drgnjenje. Zaradi izredno slabih barvnih obstojnosti na svetlobi bi bilo potiskano pletivo PA 6,6 sicer uporabno za pralne pleničke, vendar ne za sušenje na neposredni sončni svetlobi, pri čemer je plenica izpostavljena UV-žarkom. Zaradi slabše barvne odzivnosti potiskanega pletiva PA 6,6 na spremembo vrednosti pH je oblikovana halokromna tekstilija primerna le za ugotavljanje vlažnosti plenice, medtem ko bi bila za diagnosticiranje urinskih težav primernejša uporaba še dodatnih indikatorjev.

• Language: Slovenian
• Keywords: pH-odzivno barvilo, bromophenol modro, poliamid 6, 6, direktni tisk, pametna tekstilija, halokromna tekstilija, pralna plenica
• Work type: Master's thesis/paper
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Year: 2022
• PID: 20.500.12556/RUL-137587
• Publication date in RUL: 22.06.2022

Secondary language

• Language: English
• Title: Design of pH responsive textile sensor for washable cloth diapers

Abstract

The production of smart textiles, including halochromic textiles that respond to changes in pH by changing colour, is increasing year by year. Disposable nappies for babies can be classified as passive textiles because they contain an indicator dye, and their colour change depends on the wetness of the nappy containing urea. It visually indicates to the wearer that the wet nappy should be replaced with a dry one. The indicator dye that shows the wetness of a baby nappy was not found in reusable nappies. Therefore, as part of this MSc work, a halochromic textile made of PA 6.6 knitted fabric was developed that is suitable for the production of washable nappies. The dye bromophenol blue (BPB) was applied to PA 6.6 knitted fabric using a direct printing method with a flat screen-printing process. The colour and colour response of the printed knitwear to changes in pH were evaluated spectrophotometrically before and after the printed samples were immersed in buffer solutions with different pH-values. The colour fastness of the printed knitwear to washing, rubbing and light was carried out in accordance with the applicable SIST EN ISO standards. The results of the study showed that BPB had an excellent colour reaction in buffer solutions, while the colour reaction of the BPB dye bound to the PA 6.6 knitwear was less pronounced. The latter was attributed to the binding of the dye to the fibre and the strength of the dye-fibre interactions, which hinder the protonation and deprotonation of the dye. The colour fastness of printed PA 6.6 knitwear when washed at 60 °C and rubbed is very good to excellent. Due to its extremely poor colour fastness to light, printed PA 6.6 knitwear might be suitable for washable nappies but not for drying in direct sunlight where it is exposed to UV rays. Due to the poor colour response of the printed PA 6.6 knitwear to changes in pH, the designed halochromic knitwear could only be suitable for detecting wetness of the nappy, while the use of additional indicator dyes would be more suitable for diagnosing urinary problems.

• Keywords: pH-responsive dye, bromophenol blue, polyamide 6.6, direct printing, smart textile, halochromic textile, washable nappy