End-of-Life Liquid Crystal Displays Recycling: Physico-Chemical Properties of Recovered Liquid Crystals
This report focuses particularly on liquid crystals display (LCD) panels because they represent a significant amount of all WEEE collected. Technologies involving liquid crystals (LCs) have enjoyed considerable success since the 1970s in all fields of LC displays (LCDs). This currently provokes the...
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-11-01
|
| Series: | Crystals |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4352/12/11/1672 |
| _version_ | 1797465558604578816 |
|---|---|
| author | Idriss Moundoungou Zohra Bouberka Guy-Joël Fossi Tabieguia Ana Barrera Yazid Derouiche Frédéric Dubois Philippe Supiot Corinne Foissac Ulrich Maschke |
| author_facet | Idriss Moundoungou Zohra Bouberka Guy-Joël Fossi Tabieguia Ana Barrera Yazid Derouiche Frédéric Dubois Philippe Supiot Corinne Foissac Ulrich Maschke |
| author_sort | Idriss Moundoungou |
| collection | DOAJ |
| description | This report focuses particularly on liquid crystals display (LCD) panels because they represent a significant amount of all WEEE collected. Technologies involving liquid crystals (LCs) have enjoyed considerable success since the 1970s in all fields of LC displays (LCDs). This currently provokes the problem of waste generated by such equipment. Based on current statistical data, the LC amount represents approximately 1.3 g for a 35-inch diameter LCD panel unit possessing a total weight of 15 kg. In France, a recent study revealed LCD waste to represent an average of 5.6 panels per household. This represents an important quantity of LCs, which are generally destroyed by incineration or washed out with detergents during the recycling processes of end-of-life (EOL) LCDs. Hence, the aim of this study is to show that it is possible to remove LC molecules from EOL-LCD panels with the goal of valorizing them in new sectors. EOL-LCD panels have undergone various stages of dismantling, chemical treatments and characterization. The first stage of manual dismantling enables the elimination of the remaining physical components of the panels to process LC molecules only, sandwiched between the two glass plates. Mechanical treatment by scraping allows us to obtain a concentrate of LCs. The results obtained from chemical and physical techniques show that these molecules retain the characteristics essential for their operation in the field of optical and electro-optical devices. As the use of LCD surfaces continues to rise significantly, the amounts and economic stakes are huge, fully justifying the development of an LC recovery process for used panels. Many potential uses have been identified for these LC molecules: in new flat LCD panels after purification of the LCs concentrate, in PDLC systems, as lubricants or in thermal applications. |
| first_indexed | 2024-03-09T18:24:12Z |
| format | Article |
| id | doaj.art-23d5cb435c0c40779474ddaf5f2f306f |
| institution | Directory Open Access Journal |
| issn | 2073-4352 |
| language | English |
| last_indexed | 2024-03-09T18:24:12Z |
| publishDate | 2022-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Crystals |
| spelling | doaj.art-23d5cb435c0c40779474ddaf5f2f306f2023-11-24T08:02:49ZengMDPI AGCrystals2073-43522022-11-011211167210.3390/cryst12111672End-of-Life Liquid Crystal Displays Recycling: Physico-Chemical Properties of Recovered Liquid CrystalsIdriss Moundoungou0Zohra Bouberka1Guy-Joël Fossi Tabieguia2Ana Barrera3Yazid Derouiche4Frédéric Dubois5Philippe Supiot6Corinne Foissac7Ulrich Maschke8Unité Matériaux et Transformations (UMET), UMR 8207, CNRS, INRAE, Centrale Lille, Université de Lille, 59000 Lille, FranceUnité Matériaux et Transformations (UMET), UMR 8207, CNRS, INRAE, Centrale Lille, Université de Lille, 59000 Lille, FranceUnité Matériaux et Transformations (UMET), UMR 8207, CNRS, INRAE, Centrale Lille, Université de Lille, 59000 Lille, FranceUnité Matériaux et Transformations (UMET), UMR 8207, CNRS, INRAE, Centrale Lille, Université de Lille, 59000 Lille, FranceUnité Matériaux et Transformations (UMET), UMR 8207, CNRS, INRAE, Centrale Lille, Université de Lille, 59000 Lille, FranceUR 4476, Unité de Dynamique et Structure des Matériaux Moléculaires (UDSMM), Université du Littoral Côte d’Opale, 59379 Dunkerque, FranceUnité Matériaux et Transformations (UMET), UMR 8207, CNRS, INRAE, Centrale Lille, Université de Lille, 59000 Lille, FranceUnité Matériaux et Transformations (UMET), UMR 8207, CNRS, INRAE, Centrale Lille, Université de Lille, 59000 Lille, FranceUnité Matériaux et Transformations (UMET), UMR 8207, CNRS, INRAE, Centrale Lille, Université de Lille, 59000 Lille, FranceThis report focuses particularly on liquid crystals display (LCD) panels because they represent a significant amount of all WEEE collected. Technologies involving liquid crystals (LCs) have enjoyed considerable success since the 1970s in all fields of LC displays (LCDs). This currently provokes the problem of waste generated by such equipment. Based on current statistical data, the LC amount represents approximately 1.3 g for a 35-inch diameter LCD panel unit possessing a total weight of 15 kg. In France, a recent study revealed LCD waste to represent an average of 5.6 panels per household. This represents an important quantity of LCs, which are generally destroyed by incineration or washed out with detergents during the recycling processes of end-of-life (EOL) LCDs. Hence, the aim of this study is to show that it is possible to remove LC molecules from EOL-LCD panels with the goal of valorizing them in new sectors. EOL-LCD panels have undergone various stages of dismantling, chemical treatments and characterization. The first stage of manual dismantling enables the elimination of the remaining physical components of the panels to process LC molecules only, sandwiched between the two glass plates. Mechanical treatment by scraping allows us to obtain a concentrate of LCs. The results obtained from chemical and physical techniques show that these molecules retain the characteristics essential for their operation in the field of optical and electro-optical devices. As the use of LCD surfaces continues to rise significantly, the amounts and economic stakes are huge, fully justifying the development of an LC recovery process for used panels. Many potential uses have been identified for these LC molecules: in new flat LCD panels after purification of the LCs concentrate, in PDLC systems, as lubricants or in thermal applications.https://www.mdpi.com/2073-4352/12/11/1672WEEEliquid crystal displaysliquid crystalsrecycling |
| spellingShingle | Idriss Moundoungou Zohra Bouberka Guy-Joël Fossi Tabieguia Ana Barrera Yazid Derouiche Frédéric Dubois Philippe Supiot Corinne Foissac Ulrich Maschke End-of-Life Liquid Crystal Displays Recycling: Physico-Chemical Properties of Recovered Liquid Crystals Crystals WEEE liquid crystal displays liquid crystals recycling |
| title | End-of-Life Liquid Crystal Displays Recycling: Physico-Chemical Properties of Recovered Liquid Crystals |
| title_full | End-of-Life Liquid Crystal Displays Recycling: Physico-Chemical Properties of Recovered Liquid Crystals |
| title_fullStr | End-of-Life Liquid Crystal Displays Recycling: Physico-Chemical Properties of Recovered Liquid Crystals |
| title_full_unstemmed | End-of-Life Liquid Crystal Displays Recycling: Physico-Chemical Properties of Recovered Liquid Crystals |
| title_short | End-of-Life Liquid Crystal Displays Recycling: Physico-Chemical Properties of Recovered Liquid Crystals |
| title_sort | end of life liquid crystal displays recycling physico chemical properties of recovered liquid crystals |
| topic | WEEE liquid crystal displays liquid crystals recycling |
| url | https://www.mdpi.com/2073-4352/12/11/1672 |
| work_keys_str_mv | AT idrissmoundoungou endoflifeliquidcrystaldisplaysrecyclingphysicochemicalpropertiesofrecoveredliquidcrystals AT zohrabouberka endoflifeliquidcrystaldisplaysrecyclingphysicochemicalpropertiesofrecoveredliquidcrystals AT guyjoelfossitabieguia endoflifeliquidcrystaldisplaysrecyclingphysicochemicalpropertiesofrecoveredliquidcrystals AT anabarrera endoflifeliquidcrystaldisplaysrecyclingphysicochemicalpropertiesofrecoveredliquidcrystals AT yazidderouiche endoflifeliquidcrystaldisplaysrecyclingphysicochemicalpropertiesofrecoveredliquidcrystals AT fredericdubois endoflifeliquidcrystaldisplaysrecyclingphysicochemicalpropertiesofrecoveredliquidcrystals AT philippesupiot endoflifeliquidcrystaldisplaysrecyclingphysicochemicalpropertiesofrecoveredliquidcrystals AT corinnefoissac endoflifeliquidcrystaldisplaysrecyclingphysicochemicalpropertiesofrecoveredliquidcrystals AT ulrichmaschke endoflifeliquidcrystaldisplaysrecyclingphysicochemicalpropertiesofrecoveredliquidcrystals |