scholarly journals Ultrasonic-assisted melt blending for polyvinyl alcohol/carbon dots luminescent flexible films

2019 ◽  
Author(s):  
Liszulfah Roza ◽  
Permono Adi Putro ◽  
Isnaeni
Keyword(s):  
Polyvinyl Alcohol ◽  
Carbon Dots ◽  
Melt Blending ◽  
Flexible Films ◽  
Ultrasonic Assisted

Ultrasonic-assisted green extraction of peach gum polysaccharide for blue-emitting carbon dots synthesis

2021 ◽  
Vol 24 ◽  
pp. 100555
Author(s):  
Ruyuan Zhang ◽  
Lei Wang ◽  
Fatima-ezzahra Ettoumi ◽  
Miral Javed ◽  
Li Li ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Green Extraction ◽  
Ultrasonic Assisted ◽  
Peach Gum

Flexible polyvinyl alcohol/2-hydroxypropanoic acid films: effect of residual acetyl moieties on mechanical, thermal and antibacterial properties

2015 ◽  
Vol 35 (4) ◽  
pp. 319-327 ◽  
Author(s):  
Martina Hrabalikova ◽  
Martha Merchan ◽  
Solongo Ganbold ◽  
Vladimir Sedlarik ◽  
Pavel Valasek ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Polyvinyl Alcohol ◽  
Antibacterial Properties ◽  
Degree Of Hydrolysis ◽  
Mechanical And Thermal Properties ◽  
Hydrolysis Degree ◽  
Flexible Films ◽  
Agar Diffusion Test ◽  
Extended Interaction ◽  
Hydrolysis Of

Abstract This work ascertains the effect of the degree of hydrolysis of polyvinyl alcohol under extended interaction with 2-hydroxypropanoic acid (lactic acid). Systems based on three different types of polyvinyl alcohol matrices (of hydrolysis degree 80, 88 and 98 mol%) and lactic acid were characterized according to their physicochemical, mechanical and thermal properties. An agar diffusion test and the dilution and spread plate technique were conducted to facilitate antibacterial activity to counteract Staphylococcus aureus and Escherichia coli. A mathematical model was applied to the experimental data to estimate the antibacterial efficacy of the resultant flexible films.

scholarly journals Green synthesis of water-soluble fluorescent carbon dots from rosemary leaves: Applications in food storage capacity, fingerprint detection, and antibacterial activity

2020 ◽  
pp. 174751982095382
Author(s):  
Hasan Eskalen ◽  
Mustafa Çeşme ◽  
Süleyman Kerli ◽  
Şükrü Özğan
Keyword(s):  
Standard Deviation ◽  
Polyvinyl Alcohol ◽  
Glass Surface ◽  
Carbon Dots ◽  
Water Soluble ◽  
Carbon Dot ◽  
X Ray ◽  
Fluorescent Carbon Dots ◽  
Fingerprint Detection ◽  
Fluorescent Carbon

Blue fluorescent carbon dots are synthesized via a one-step hydrothermal method using rosemary leaves as a carbon source. The obtained carbon dots are characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, UV-Vis, FTIR, and fluorescence spectrometry. The results show that carbon dots gave a maximum emission peak at 422 nm when excited at 332 nm. The average particle diameter of the synthesized spherical carbon dots is found to be 16.13 nm with a 4.6-nm standard deviation. The diameters of the produced carbon dots vary, as is evident from standard deviation heights, resulting in multicolor emission spectra. The fruit storage experiment is carried out by investigating the qualitative antioxidant ability of the produced carbon dots. The results obtained for polyvinyl alcohol–carbon dot–coated samples differ remarkably compared to polyvinyl alcohol–coated samples only. The polyvinyl alcohol–carbon dot composition is used in latent fingerprint detection applications. In analyses made on a glass surface, fingerprints cannot be monitored on the glass surface with the polyvinyl alcohol layer under ultraviolet light, while they are observed on the surface covered with the polyvinyl alcohol–carbon dot composition. Moreover, biological activity against Gram-positive, Gram-negative, and yeast strains are investigated.

Fluorescent polyvinyl alcohol films based on nitrogen and sulfur co-doped carbon dots towards white light-emitting devices

2016 ◽  
Vol 40 (10) ◽  
pp. 8710-8716 ◽  
Author(s):  
Yaling Wang ◽  
Yongqiang Zhao ◽  
Feng Zhang ◽  
Lin Chen ◽  
Yongzhen Yang ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
White Light ◽  
Carbon Dots ◽  
Light Emitting ◽  
Color Coordinates ◽  
Light Emitting Devices ◽  
Warm White Light ◽  
Doped Carbon Dots ◽  
Co Doped ◽  
Polyvinyl Alcohol Films

Warm white light with color coordinates of (0.40, 0.38) and CCT of 3980 K was obtained using NS-CDs and PVA.

scholarly journals Spectroscopy Study of Polyvinyl Alcohol/Carbon Dots Composite Films

2021 ◽  
Vol 18 (7) ◽  
Author(s):  
Permono Adi PUTRO ◽  
Nurfina YUDASARI ◽  
Isnaeni Isnaeni ◽  
Akhiruddin MADDU
Keyword(s):  
Polyvinyl Alcohol ◽  
Low Temperatures ◽  
Carbon Dots ◽  
Electrochemical Impedance ◽  
Composite Films ◽  
Optical And Electrical Properties ◽  
Spectroscopy Study ◽  
Vis Spectroscopy ◽  
Cassava Peels ◽  
Absorbance Spectra

The unique characteristic of carbon dots (C-dots), such as optical and electrical properties, have been integrated into polyvinyl alcohol (PVA) to realize composites with synergistic. In this work, C-dots have been synthesized from inner cassava peels using simple methods at low temperatures. The C-dots were added to PVA, which is influenced the characteristic based on spectroscopy. The complex formation between PVA and C-dots was investigated by FTIR spectroscopy. The C-dots contributed to UV-Vis spectroscopy characteristic of PVA/C-dots with the absence of a new peak of absorbance spectra. Besides, C-dots also supported the electrochemical impedance spectroscopy characteristic of PVA/C-dots, so the highest ionic conductivity is induced by the enhancement of amorphous PVA when the c-dots content is increased.

Remarkable enhancement of ambient-air electrical conductivity of the perylenediimide π-stacks isolated in the flexible films of a hydrogen-bonded polymer

RSC Advances ◽  
2015 ◽  
Vol 5 (79) ◽  
pp. 64240-64246 ◽  
Author(s):  
Mustafa Supur ◽  
Ayhan Yurtsever ◽  
Ümit Akbey
Keyword(s):  
Electrical Conductivity ◽  
Hydrogen Bonding ◽  
Polyvinyl Alcohol ◽  
Aqueous Solutions ◽  
Ambient Air ◽  
Π Interactions ◽  
Flexible Films ◽  
Hydrogen Bonded

N,N′-di(2-(trimethylammoniumiodide)ethylene) perylenediimide (TAIPDI), forming extensive π-stacks through the strong π–π interactions of large π-planes, was isolated in the hydrogen-bonding milieu of polyvinyl alcohol (PVA) from aqueous solutions.

scholarly journals Development of biodegradable smart packaging from chitosan, polyvinyl alcohol (PVA) and butterfly pea flower’s (Clitoria ternatea L.) anthocyanin extract

Food Research ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 307-314
Author(s):  
N.A. Hidayati ◽  
M.W. Wijaya ◽  
V.P. Bintoro ◽  
S. Mulyani ◽  
Y. Pratama
Keyword(s):  
Polyvinyl Alcohol ◽  
Food System ◽  
Colour Change ◽  
Anthocyanin Content ◽  
Ph Change ◽  
Total Anthocyanin ◽  
Clitoria Ternatea ◽  
Smart Packaging ◽  
Ultrasonic Assisted ◽  
Butterfly Pea

Active compounds from natural sources such as butterfly pea flowers (Clitoria ternatea L.) such as anthocyanin was found able to be integrated with chitosan and Polyvinyl Alcohol (PVA) polymers in their application as smart packaging. Smart packaging that contains anthocyanin shows a colour response to changes in pH due to food spoilage. This study was aimed to evaluate the effects of chitosan (CH) and PVA proportion on the quality of biodegradable film incorporating butterfly pea flower’s anthocyanin (BPFA) extract included film thickness, tensile strength (TS), elongation (E%), total anthocyanin content and the film colour response at different pH range were characterized. Concentrated anthocyanin extract was obtained from butterfly pea flower petals in ultrasonic-assisted leaching using ethanol as a solvent and followed by rotary vacuum evaporation. The film-forming solution was prepared from a binary mixture of CH:PVA in the ratio of 20:80, 40:60, 60:40, and 80:20. The results showed that films obtained from all combinations could exhibit different colour responses in various pH ranges, indicating the successful incorporation of anthocyanin. The film with CH:PVA ratio of 40:60 showed a more pronounced colour change, among other treatments. It was also characterized by a thickness of 0.15 mm, TS of 11.02 MPa, E% of 48.00%, and total anthocyanin of 25.08 mg/g. The film showed high potential to be used as biodegradable smart packaging for the food system which produces pH change upon deterioration.

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