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- Valencia, Luis, 1990-, et al.
(författare)
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Bio-based Micro-/Meso-/Macroporous Hybrid Foams with Ultrahigh Zeolite Loadings for Selective Capture of Carbon Dioxide
- 2019
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 11:43, s. 40424-40431
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Tidskriftsartikel (refereegranskat)abstract
- Microporous (<2 nm) crystalline aluminosilicates in the form of zeolites offer a great potential as efficient adsorbents for atmospheric CO2 in the eminent battle against global warming and climate change. The processability of conventional zeolite powders is, however, poor, which limits their implementation in many applications, such as in gas filtration industrial systems. In this work, we overcome this issue through the preparation of hybrid foams using mesoporous/macroporous supporting materials based on the strong network properties of gelatin/nanocellulose, which can support ultrahigh loadings of silicalite-1, used as a model sorbent nanomaterial. We achieved up to 90 wt % of zeolite content and a microporous/mesoporous/macroporous hybrid material. The application of hybrid foams for selective CO2 sorption exhibits a linear relationship between the zeolite content and CO2 adsorption capacity and high selectivity over N2, where the gelatin/nanocellulose foam efficiently supports the zeolite crystals without apparently blocking their pores.
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| 2. |
- Valencia, Luis, 1990-
(författare)
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Cellulose Nanofibril-based Hybrid Materials : Eco-friendly design towards separation and packaging applications
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Nanocellulose has been lately considered as the “Holy-Grail” in the design of sustainable materials due to its bio-origin and an unprecedented combination of prominent features, including good mechanical properties, anisotropy and versatile surface chemistry. In addition, nanocellulose in the form of cellulose nanofibrils, can adopt variable structures and morphologies depending on the processing technique, such as aerogels, films and monoliths.However, there are limitations that hinder the implementation of cellulose nanofibrils in “real-life applications”, such as inherent interaction with bacteria and proteins, thus leading to surface-fouling; and loss of integrity due to water-induced swelling. A way to overcome these challenges, and provide further functionality, is through hybridization strategies, at which the multiple components act synergistically towards specific properties and applications. In this thesis, the aim is to present multiple strategies for the synthesis of novel cellulose nanofibril-based hybrid materials, in the form of 2D-films and 3D-foams, towards their employment for separation applications or active food packaging.A novel strategy to surface-functionalize cellulose nanofibril-membranes is proposed via grafting zwitterionic polymer brushes of poly (cysteine methacrylate). The modification can suppress the absorption of proteins in an 85%, as well as decreasing the adhesion of bacteria in an 87%, while introducing antimicrobial properties, as demonstrated against S. aureus.The spontaneous formation of functional metal oxide nanoparticles occurring in situ on cellulose nanofibrils-films during the adsorption of metal ions from water is investigated, which occurs without the additional use of chemicals or temperature. Notably, this process not only enables the upcycling of materials through multi-stage applications, but also provides a cost-effective method to prepare multifunctional hybrid materials with enhanced dye-removal/antimicrobial activity.The processing of functional composite films from cellulose nanofibril-stabilized Pickering emulsions and their suitability to be used as active edible barriers was demonstrated. The presence of oil in the films fine-tuned the properties of the films, as well as acted as the medium to encapsulate bio-active hydrophobic compounds, providing further functionality such as antioxidant and antimicrobial properties.Anisotropic porous hybrid foams with ultra-high loading capacity of sorbents (e.g., zeolites and metal-organic frameworks) were produced via unidirectional freeze-casting method using cellulose nanofibrils/gelatin as template material. The foams indeed exhibited ultra-high loading capacity of sorbent nanomaterials, a linear relationship between sorbent content and CO2 adsorption capacity, and high CO2/N2 selectivity.
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