Studying functional properties of hydrogel and silicone–hydrogel contact lenses with PALS, MIR and Raman spectroscopy

Filipecki, J.; Sitarz, Maciej; Kocela, Agnieszka; Kotynia, Katarzyna; Jeleń, Piotr; Filipecka, Katarzyna; Gawęda, M.

doi:10.1016/j.saa.2014.04.144

Cited by 17 publications

(11 citation statements)

References 14 publications

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“…Some other researchers have also discovered that determining the change in water content helps study the changing trend of COF when using lenses. Water molecules exhibit a bipolar structure and bind to the surface of the phosphoryl choline in the contact lens, thereby inhibiting the binding of other molecules and decreasing the friction coefficient of the lens [28]. In addition, from a physiological point of view, the oxygen permeability coefficient is the most important parameter characterising the contact lens.…”

Section: Resultsmentioning

confidence: 99%

Tribological behaviour of two kinds of typical hydrogel contact lenses in different lubricants

Qin

Zhu

Zhou

et al. 2019

Biosurface and Biotribology

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Contact lenses have a special effect on the treatment of some eye diseases. The tribological behaviour of soft contact lenses considerably influences their clinical performance. Improper wearing of contact lenses can lead to mechanical damage of the contact interface, which can lead to pathological changes in the eyeball. In this study, the sliding friction of two kinds of typical contact lens materials (hilaficon-B and lotrafilcon-B) in three lubricants (distilled water, care solution, and eye drop) and tribological parameters are studied, using PMMA as a control. Hydrogels have high water content but the dehydration rate is high. Silicone hydrogels have low initial water content but low dehydration rates. The friction test in distilled water gives the highest coefficient of friction value. The care solution and eye drop significantly reduce the friction coefficient of the lens due to the formation of tribofilm.

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Section: Resultsmentioning

confidence: 99%

Tribological behaviour of two kinds of typical hydrogel contact lenses in different lubricants

Qin

Zhu

Zhou

et al. 2019

Biosurface and Biotribology

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“…The results of the calculations of mean positron lifetime values for the materials investigated revealed the existence of three components, τ1, τ2 and τ3, with the intensities I1, I2 and I3, respectively. In our previous studies [19,23], we have and their intensities I1 and I2 by using a positron annihilation two-state model. The mean positron lifetime values and their intensities are collected in Table 2.…”

Section: Resultsmentioning

confidence: 99%

Investigation of the Degree of Disorder of the Structure of Polymer Soft Contact Lenses Using Positron Annihilation Lifetime Spectroscopy PALS

Filipecki¹,

Kotynia²,

Filipecka³

2016

Polim. Med.

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“…The FTIR studies were carried out on a DigiLab Excalibur series spectrometer (Digilab Inc., Hopkinton, USA) equipped with a Pike MIRacle TM attenuated total reflection (ATR) attachment (PIKE Technologies Inc., Madison, USA). 21 A total of 128 scans were accumulated in the range of 550-4000 cm −1 and the resolution was set at 4 cm −1 .…”

Section: Methodsmentioning

confidence: 99%

“…A minimum of 120 scans with integration times of 0.3-0.5 s and a resolution of 3 cm −1 were collected and averaged. 21…”

Section: Methodsmentioning

confidence: 99%

A study of the effect of X-ray irradiation on the structure of Narafilcon A biopolymer soft contact lenses

Filipecka¹,

Budaj²,

B³

et al. 2018

Polim. Med.

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Background. The effects of external factors such as X-ray irradiation on the structure and physical properties of contact lenses are very important for both the patients using contact lenses and medical personnel. Objectives. The aim of the study was to investigate the effect of X-rays on the structure of Narafilcon A silicone-hydrogel contact lenses. Material and methods. In order to study the structural changes caused by X-rays in Narafilcon A polymer contact lenses, the following spectroscopy methods were used: positron annihilation lifetime spectroscopy (PALS), Fourier transform middle infrared spectroscopy (FTIR) and Raman spectroscopy (RS). Irradiation of the investigated sample was carried out using an Elekta Synergy accelerator. The contact lenses were irradiated with the following total doses of X-rays: 0.05 Gy, 0.5 Gy, 0.8 Gy, and 1.0 Gy. Results. The PALS measurements showed that X-ray irradiation caused slight changes in the size of the free volume and the fractional free volume in the structure of the polymer contact lenses examined. However, the FTIR and RS measurements showed that X-rays did not break the monomer bonds in the polymeric structure of the sample. Conclusions. The changes revealed by the PALS method may be related to possible displacement of monomer chains, resulting in changes in the dimensions and numbers of free volumes. The finding that X-ray radiation does not affect or damage polymer bonds can in the future contribute to the use of X-ray and gamma radiation to sterilize contact lenses.

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Studying functional properties of hydrogel and silicone–hydrogel contact lenses with PALS, MIR and Raman spectroscopy

Cited by 17 publications

References 14 publications

Tribological behaviour of two kinds of typical hydrogel contact lenses in different lubricants

Tribological behaviour of two kinds of typical hydrogel contact lenses in different lubricants

Investigation of the Degree of Disorder of the Structure of Polymer Soft Contact Lenses Using Positron Annihilation Lifetime Spectroscopy PALS

A study of the effect of X-ray irradiation on the structure of Narafilcon A biopolymer soft contact lenses

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