| 1. |
- Abrahamsson, Tobias, et al.
(författare)
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Investigating the role of polymer size on ionic conductivity in free-standing hyperbranched polyelectrolyte membranes
- 2021
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Ingår i: Polymer. - : Elsevier. - 0032-3861 .- 1873-2291. ; 223
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Tidskriftsartikel (refereegranskat)abstract
- Polymer-based ion exchange membranes (IEMs) are utilized for many applications such as in water desalination, energy storage, fuel cells and in electrophoretic drug delivery devices, exemplified by the organic electronic ion pump (OEIP). The bulk of current research is primarily focused on finding highly conductive and stable IEM materials. Even though great progress has been made, a lack of fundamental understanding of how specific polymer properties affect ionic transport capabilities still remains. This leads to uncertainty in how to proceed with synthetic approaches for designing better IEM materials. In this study, an investigation of the structure-property relationship between polymer size and ionic conductivity was performed by comparing a series of membranes, based on ionically charged hyperbranched polyglycerol of different polymer sizes. Observing an increase in ionic conductivity associated with increasing polymer size and greater electrolyte exclusion, indi-cating an ionic transportation phenomenon not exclusively based on membrane electrolyte uptake. These findings further our understanding of ion transport phenomena in semi-permeable membranes and indicate a strong starting point for future design and synthesis of IEM polymers to achieve broader capabilities for a variety of ion transport-based applications.
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| 2. |
- Ail, Ujwala, et al.
(författare)
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Effect of Sulfonation Level on Lignin/Carbon Composite Electrodes for Large-Scale Organic Batteries
- 2020
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Ingår i: ACS Sustainable Chemistry and Engineering. - : AMER CHEMICAL SOC. - 2168-0485. ; 8:49, s. 17933-17944
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Tidskriftsartikel (refereegranskat)abstract
- The key figure-of-merit for materials in stationary energy storage applications, such as large-scale energy storage for buildings and grids, is the cost per kilo per electrochemical cycle, rather than the energy density. In this regard, forest-based biopolymers such as lignin, are attractive, as they are abundant on Earth. Here, we explored lignin as an electroactive battery material, able to store two electrons per hydroquinone aromatic ring, with the targeted operation in aqueous electrolytes. The impact of the sulfonation level of lignin on the performance of its composite electrode with carbon was investigated by considering three lignin derivatives: lignosulfonate (LS), partially desulfonated lignosulfonate (DSLS), and fully desulfonated lignin (KL, lignin produced by the kraft process). Partial desulfonation helped in better stability of the composite in aqueous media, simultaneously favoring its water processability. In this way, a route to promote ionic conductivity within the lignin/carbon composite electrodes was developed, facilitating the access to the entire bulk of the volumetric electrodes. Electrochemical performance of DSLS/C showed highly dominant Faradaic contribution (66%) towards the total capacity, indicating an efficient mixed ionic-electronic transport within the lignin-carbon phase, displaying a capacity of 38 mAh/g at 0.25 A/g and 69% of capacity retention after 2200 cycles at a rate of 1 A/g.
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| 3. |
- Ail, Ujwala, et al.
(författare)
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Lignin Functionalized with Catechol for Large-Scale Organic Electrodes in Bio-Based Batteries
- 2023
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Ingår i: ADVANCED ENERGY AND SUSTAINABILITY RESEARCH. - : WILEY. - 2699-9412. ; 4:12
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Tidskriftsartikel (refereegranskat)abstract
- Lignin, obtained as a waste product in huge quantities from the large-scale cellulose processing industries, holds a great potential to be used as sustainable electrode material for large-scale electroactive energy storage systems. The fixed number of redox-active phenolic groups present within the lignin structure limits the electrochemical performance and the total energy storage capacity of the lignin-based electrodes. Herein, the way to enhance the charge storage capacity of lignin by incorporating additional small catechol molecules into the lignin structure is demonstrated. The catechol derivatives are covalently attached to the lignin via aromatic electrophilic substitution reaction. The increased phenolic groups in all functionalized lignin derivatives notably increase the values of capacitance compared to pristine lignin. Further, solvent fractionation of lignin followed by functionalization using catechol boosts three times the charge capacity of lignin electrode. Herein, a scalable, cost-effective method to enhance the electrochemical performance of lignin electrodes via incorporation of small redox active moieties into the lignin structure is demonstrated. Solvent fractionation of lignin followed by functionalization using catechol increases the charge storage capacity of the lignin-carbon composite electrode by a factor of 3 reaching record high charge capacity above 100 mAh g-1.
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| 4. |
- Alarcon, E I, et al.
(författare)
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Coloured cornea replacements with anti-infective properties : expanding the safe use of silver nanoparticles in regenerative medicine.
- 2016
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Ingår i: Nanoscale. - : Royal Society of Chemistry. - 2040-3364 .- 2040-3372. ; 8:12, s. 6484-6489
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Tidskriftsartikel (refereegranskat)abstract
- Despite the broad anti-microbial and anti-inflammatory properties of silver nanoparticles (AgNPs), their use in bioengineered corneal replacements or bandage contact lenses has been hindered due to their intense yellow coloration. In this communication, we report the development of a new strategy to pre-stabilize and incorporate AgNPs with different colours into collagen matrices for fabrication of corneal implants and lenses, and assessed their in vitro and in vivo activity.
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| 5. |
- Balion, Zbigniev, et al.
(författare)
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Investigation of Cancer Cell Migration and Proliferation on Synthetic Extracellular Matrix Peptide Hydrogels
- 2020
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Ingår i: Frontiers in Bioengineering and Biotechnology. - : FRONTIERS MEDIA SA. - 2296-4185. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Chemical and mechanical properties of a tumor microenvironment are essential players in cancer progression, and it is important to precisely control the extracellular conditions while designing cancerin vitromodels. The study investigates synthetic hydrogel matrices from multi-arm polyethylene glycol (PEG) functionalized with collagen-like peptide (CLP) CG(PKG)(4)(POG)(4)(DOG)(4)alone and conjugated with either cell adhesion peptide RGD (mimicking fibronectin) or IKVAV (mimicking laminin). Human glioblastoma HROG36, rat C6 glioma cells, and A375 human melanoma cells were grown on the hydrogels and monitored for migration, proliferation, projected cell area, cell shape index, size and number, distribution of focal contacts in individual cells, and focal adhesion number. PEG-CLP-RGD induced migration of both glioma cell lines and also stimulated proliferation (assessed as metabolic activity) of HROG36 cells. Migration of C6 cells were also stimulated by PEG-CLP-IKVAV. These responses strongly correlated with the changes in adhesion and morphology parameters of individual cells - projected cell area, cell shape index, and focal contact number. Melanoma A375 cell proliferation was increased by PEG-CLP-RGD, and this was accompanied by a decrease in cell shape index. However, neither RGD nor IKVAV conjugated to PEG-CLP stimulated migratory capacity of A375 cells. Taken together, the study presents synthetic scaffolds with extracellular matrix (ECM)-mimicking peptides that allow for the exploration of the effect of ECM signaling to cancer cells.
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| 6. |
- Che, Canyan, 1988-, et al.
(författare)
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Twinning Lignosulfonate with a Conducting Polymer via Counter-Ion Exchange for Large-Scale Electrical Storage
- 2019
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Ingår i: Advanced Sustainable Systems. - : Wiley-VCH Verlag. - 2366-7486. ; 3:9
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Tidskriftsartikel (refereegranskat)abstract
- Lignosulfonate (LS) is a large-scale surplus product of the forest and paper industries, and has primarily been utilized as a low-cost plasticizer in making concrete for the construction industry. LS is an anionic redox-active polyelectrolyte and is a promising candidate to boost the charge capacity of the positive electrode (positrode) in redox-supercapacitors. Here, the physical-chemical investigation of how this biopolymer incorporates into the conducting polymer PEDOT matrix, of the positrode, by means of counter-ion exchange is reported. Upon successful incorporation, an optimal access to redox moieties is achieved, which provides a 63% increase of the resulting stored electrical charge by reversible redox interconversion. The effects of pH, ionic strength, and concentrations, of included components, on the polymer–polymer interactions are optimized to exploit the biopolymer-associated redox currents. Further, the explored LS-conducting polymer incorporation strategy, via aqueous synthesis, is evaluated in an up-scaling effort toward large-scale electrical energy storage technology. By using an up-scaled production protocol, integration of the biopolymer within the conducting polymer matrix by counter-ion exchange is confirmed and the PEDOT-LS synthesized through optimized strategy reaches an improved charge capacity of 44.6 mAh g−1.
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| 7. |
- Islam, Mohammad Mirazul, et al.
(författare)
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Self-assembled collagen-like-peptide implants as alternatives to human donor corneal transplantation
- 2016
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Ingår i: RSC Advances. - : ROYAL SOC CHEMISTRY. - 2046-2069. ; 6:61, s. 55745-55749
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Tidskriftsartikel (refereegranskat)abstract
- Extracellular matrix proteins like collagen promote regeneration as implants in clinical studies. However, collagens are large and unwieldy proteins, making small functional peptide analogs potentially ideal substitutes. Self-assembling collagen-like-peptides conjugated with PEG-maleimide were assembled into hydrogels. When tested pre-clinically as corneal implants in mini-pigs, they promoted cell and nerve regeneration, forming neo-corneas structurally and functionally similar to natural corneas.
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| 8. |
- Khan, Farhan A., et al.
(författare)
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Surprising behavior of NXO-peptides toward the lithium hydroxide solvolysis
- 2013
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Ingår i: Tetrahedron Letters. - : Elsevier. - 0040-4039 .- 1359-8562. ; 54:28, s. 3679-3682
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Tidskriftsartikel (refereegranskat)abstract
- An unexpected rearrangement of NXO peptides was observed during solvolysis of the methyl ester using lithium hydroxide as the base. It was found that the NXO-compounds rearranged into semioxamazide derivatives in which the ester is derived from the alcohol used as the reaction solvent.
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| 9. |
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| 10. |
- Khan, Ziyauddin, et al.
(författare)
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Towards printable water-in-polymer salt electrolytes for high power organic batteries
- 2022
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Ingår i: Journal of Power Sources. - : Elsevier. - 0378-7753 .- 1873-2755. ; 524
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Tidskriftsartikel (refereegranskat)abstract
- Internet-of-things which requires electronics, energy convertor and storage must be low-cost, recyclable and environmentally friendly. In the development of printed batteries, ideally all the components (electrode and electrolyte) must be printable to ensure low-cost manufacturing via printing technologies. Most of the printed batteries suffer with low power. One of the reasons is the poor ionic conductivity of the electrolyte due to the high viscosity needed for printing relatively thick layers. In the present work we have demonstrated a new class of electrolyte promising for printed organic batteries following the concept of water-in-polymer salt electrolytes (WIPSEs). These highly concentrated electrolytes of potassium polyacrylate are non-flammable, low cost and environmentally friendly. They possess high ionic conductivities (45-87 mS/cm) independent on the macroscopic viscosities varying from 7 to 33000 cP. The decoupling between ionic transport and macroscopic viscosity enables us to demonstrate organic batteries based on WIPSEs that can deliver a high and constant power (similar to 4.5 kW/kg; 7.1-11 mW/cm(2)) independent on the viscosity of the electrolytes. The tunability of the viscosity presents a prerequisite for printed technology manufacturing and compatibility with printed batteries.
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