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R. Sharma et al.
Figure 5 presents the SEM images of Dupion silk (A), Matka silk (B) and Mulberry
silk fabric which shows the deposition of the photoluminescent pigments on the
surfaces of Dupion, Matka and Mulberry silk fabrics.
It was interesting to observe that the Dupion silk fabric (made from silk obtained
from double cocoons, fabric with a coarse texture and rough feel) and Matka silk
fabric (made from damaged cocoons, fabric with a coarse texture and rough feel) has
multiple photoluminescent pigment particles deposited on the surfaces as compared
to the Mulberry silk fabric (made from defect-free cocoons, with smooth fabric
texture) with few photoluminescent pigment particles on the surface. Therefore, the
higher luminosity of Dupion and Matlka silk fabrics can be attributed to the higher
concentration of pigments that get deposited on the surface of these fabrics due to
its coarse structure, as compared to smooth fabrics like Mulberry silk.
4.3 Visual Perception Study of Photoluminescent Pigments
by the Elderly
The curtains were placed in the 10 houses of the elderly who volunteered for the
visual perception study in their bedrooms. The interviews were taken the following
morning and the user perception of the elderly and summarized. It was observed that
even though the lux values of the printed swatches were below 1lux which is equal to
starry night as per DlN67510 Standards, the elderly were able to perceive the photoluminescence in low light conditions. It was mentioned by the elderly respondents
that the photoluminescence glow of the pigment is very soft, without glare and does
not hurt the eye. The elderly also noted that in the night if their sleep was disturbed
the nightlight may keep them awake. But now, with the photoluminescent aqua blue
glow, the sleep of the elderly respondents was not disturbed even if the respondent
woke up during nighttime. Irrespective of the level of disability and visual limitations
of the elderly, all the four bands of photoluminescent pigments were visible, with
(B1C5, G1C5) exhibiting better intensity of (0.15 lux, 0.17 lux) in comparison to
B4C5 and G4C5. Table 2 gives a comprehensive analysis of pigment correlating the
experimental readings with the visuals perception readings.
The photoluminescent pigment bands were visible distinctly as perceived by the
elderly for about 2–3 h duration with Blue pigment B1C5 exhibiting greater luminosity when compared to green G1C5 at the particle size 10–15 μm. After 4–5 h
duration, the elderly describe the photoluminescence on the curtain as a soft uniform
glow. The individual bands seem to disappear. Out of 10 participants, 5 elderly homes
experienced interference of corridor and light trespass.
Due to the interference of secondary lighting, the effect of the photoluminescent
print was minimized. Two of the homes, the curtains were placed in the dark with
no light trespass and these elderly users have given reviews to the scale of 4 out of
5. Edge definition and path-finding were rated best in these real-time dark spaces.
R. Sharma et al.
Figure 5 presents the SEM images of Dupion silk (A), Matka silk (B) and Mulberry
silk fabric which shows the deposition of the photoluminescent pigments on the
surfaces of Dupion, Matka and Mulberry silk fabrics.
It was interesting to observe that the Dupion silk fabric (made from silk obtained
from double cocoons, fabric with a coarse texture and rough feel) and Matka silk
fabric (made from damaged cocoons, fabric with a coarse texture and rough feel) has
multiple photoluminescent pigment particles deposited on the surfaces as compared
to the Mulberry silk fabric (made from defect-free cocoons, with smooth fabric
texture) with few photoluminescent pigment particles on the surface. Therefore, the
higher luminosity of Dupion and Matlka silk fabrics can be attributed to the higher
concentration of pigments that get deposited on the surface of these fabrics due to
its coarse structure, as compared to smooth fabrics like Mulberry silk.
4.3 Visual Perception Study of Photoluminescent Pigments
by the Elderly
The curtains were placed in the 10 houses of the elderly who volunteered for the
visual perception study in their bedrooms. The interviews were taken the following
morning and the user perception of the elderly and summarized. It was observed that
even though the lux values of the printed swatches were below 1lux which is equal to
starry night as per DlN67510 Standards, the elderly were able to perceive the photoluminescence in low light conditions. It was mentioned by the elderly respondents
that the photoluminescence glow of the pigment is very soft, without glare and does
not hurt the eye. The elderly also noted that in the night if their sleep was disturbed
the nightlight may keep them awake. But now, with the photoluminescent aqua blue
glow, the sleep of the elderly respondents was not disturbed even if the respondent
woke up during nighttime. Irrespective of the level of disability and visual limitations
of the elderly, all the four bands of photoluminescent pigments were visible, with
(B1C5, G1C5) exhibiting better intensity of (0.15 lux, 0.17 lux) in comparison to
B4C5 and G4C5. Table 2 gives a comprehensive analysis of pigment correlating the
experimental readings with the visuals perception readings.
The photoluminescent pigment bands were visible distinctly as perceived by the
elderly for about 2–3 h duration with Blue pigment B1C5 exhibiting greater luminosity when compared to green G1C5 at the particle size 10–15 μm. After 4–5 h
duration, the elderly describe the photoluminescence on the curtain as a soft uniform
glow. The individual bands seem to disappear. Out of 10 participants, 5 elderly homes
experienced interference of corridor and light trespass.
Due to the interference of secondary lighting, the effect of the photoluminescent
print was minimized. Two of the homes, the curtains were placed in the dark with
no light trespass and these elderly users have given reviews to the scale of 4 out of
5. Edge definition and path-finding were rated best in these real-time dark spaces.