| 1. |
- Bergfelt, Andreas, et al.
(författare)
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A Mechanical Robust yet highly Conductive Diblock Copolymer-based Solid Polymer Electrolyte for Room Temperature Structural Battery Applications
- 2020
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Ingår i: ACS Applied Polymer Materials. - : American Chemical Society (ACS). - 2637-6105. ; 2:2, s. 939-948
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we present a solid polymer electrolyte (SPE) that uniquely combines ionic conductivity and mechanical robustness. This is achieved with a diblock copolymer poly(benzyl methacrylate)-poly(ε-caprolactone-r-trimethylene carbonate). The SPE with 16.7 wt% lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) showed the highest ionic conductivity (9.1×10−6 S cm−1 at 30 °C) and apparent transference number (T+) of 0.64 ± 0.04. Due to the employment of the benzyl methacrylate hard-block, this SPE is mechanically robust with a storage modulus (E') of 0.2 GPa below 40 °C, similar to polystyrene, thus making it a suitable material also for load-bearing constructions. The cell Li|SPE|LiFePO4 is able to cycle reliably at 30 °C for over 300 cycles. The promising mechanical properties, desired for compatibility with Li-metal, together with the fact that BCT is a highly reliable electrolyte material makes this SPE an excellent candidate for next-generation all-solid-state batteries.
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| 2. |
- Gao, Ming, et al.
(författare)
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Self-assembly of cholesterol end-capped polymer micelles for controlled drug delivery
- 2020
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Ingår i: Journal of Nanobiotechnology. - : BMC. - 1477-3155. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- Background: During the past few decades, drug delivery system (DDS) has attracted many interests because it could enhance the therapeutic effects of drugs and reduce their side effects. The advent of nanotechnology has promoted the development of nanosized DDSs, which could promote drug cellular uptake as well as prolong the half-life in blood circulation. Novel polymer micelles formed by self-assembly of amphiphilic polymers in aqueous solution have emerged as meaningful nanosystems for controlled drug release due to the reversible destabilization of hydrophobic domains under different conditions.Results: The amphiphilic polymers presented here were composed of cholesterol groups end capped and poly (poly (ethylene glycol) methyl ether methacrylate) (poly (OEGMA)) as tailed segments by the synthesis of cholesterol-based initiator, followed by atom transfer radical polymerization (ATRP) with OEGMA monomer. FT-IR and NMR confirmed the successfully synthesis of products including initiator and polymers as well as the Mw of the polymers were from 33,233 to 89,088 g/mol and their corresponding PDI were from 1.25 to 1.55 by GPC. The average diameter of assembled polymer micelles was in hundreds nanometers demonstrated by DLS, AFM and SEM. The behavior of the amphiphilic polymers as micelles was investigated using pyrene probing to explore their critical micelle concentration (CMC) ranging from 2.53 x 10(-4) to 4.33 x 10(-4) mg/ml, decided by the balance between cholesterol and poly (OEGMA). Besides, the CMC of amphiphilic polymers, the quercetin (QC) feeding ratio and polarity of solvents determined the QC loading ratio maximized reaching 29.2% certified by UV spectrum, together with the corresponding size and stability changes by DLS and Zeta potential, and thermodynamic changes by TGA and DSC. More significantly, cholesterol end-capped polymer micelles were used as nanosized systems for controlled drug release, not only alleviated the cytotoxicity of QC from 8.6 to 49.9% live cells and also achieved the QC release in control under different conditions, such as the presence of cyclodextrin (CD) and change of pH in aqueous solution.Conclusions: The results observed in this study offered a strong foundation for the design of favorable polymer micelles as nanosized systems for controlled drug release, and the molecular weight adjustable amphiphilic polymer micelles held potential for use as controlled drug release system in practical application.
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| 3. |
- Gustafsson, Emil, et al.
(författare)
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Understanding interactions of plasticisers with a phospholipid monolayer
- 2024
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Ingår i: Soft Matter. - : Royal Society of Chemistry. - 1744-683X .- 1744-6848. ; 20:13, s. 2892-2899
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Tidskriftsartikel (refereegranskat)abstract
- The use of DEHP (diethylhexyl phthalate) is now banned for most applications in Europe; the exception is for blood bags, where its toxicity is overshadowed by its ability to extend the storage life of red blood cells. Another plasticiser, BTHC (butanoyl trihexyl citrate), is used in paediatric blood bags but does not stabilise blood cells as effectively. Interactions between plasticisers and lipids are investigated with a phospholipid, DMPC, to understand the increased stability of blood cells in the presence of DEHP as well as bioaccumulation and identify differences with BTHC. Mixed monolayers of DMPC and DEHP or BTHC were studied on Langmuir troughs where surface pressure/area isotherms can be measured. Neutron reflection measurements were made to determine the composition and structure of these mixed layers. A large amount of plasticiser can be incorporated into a DMPC monolayer but once an upper limit is reached, plasticiser is selectively removed from the interface at high surface pressures. The upper limit is found to occur between 40–60 mol% for DEHP and 20–40 mol% for BTHC. The areas per molecule are also different with DEHP being in the range of 50–100 Å2 and BTHC being 65–120 Å2. Results indicate that BTHC does not fit as well as DEHP in DMPC monolayers which could help explain the differences observed with regards to the stability of blood cells.
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| 4. |
- Gustafsson, Emil, et al.
(författare)
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Understanding interactions of plasticisers with a phospholipid monolayer
- 2024
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Ingår i: Soft Matter. - : Royal Society of Chemistry. - 1744-683X .- 1744-6848. ; 20:13, s. 2892-2899
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Tidskriftsartikel (refereegranskat)abstract
- The use of DEHP (diethylhexyl phthalate) is now banned for most applications in Europe; the exception is for blood bags, where its toxicity is overshadowed by its ability to extend the storage life of red blood cells. Another plasticiser, BTHC (butanoyl trihexyl citrate), is used in paediatric blood bags but does not stabilise blood cells as effectively. Interactions between plasticisers and lipids are investigated with a phospholipid, DMPC, to understand the increased stability of blood cells in the presence of DEHP as well as bioaccumulation and identify differences with BTHC. Mixed monolayers of DMPC and DEHP or BTHC were studied on Langmuir troughs where surface pressure/area isotherms can be measured. Neutron reflection measurements were made to determine the composition and structure of these mixed layers. A large amount of plasticiser can be incorporated into a DMPC monolayer but once an upper limit is reached, plasticiser is selectively removed from the interface at high surface pressures. The upper limit is found to occur between 40-60 mol% for DEHP and 20-40 mol% for BTHC. The areas per molecule are also different with DEHP being in the range of 50-100 Å2 and BTHC being 65-120 Å2. Results indicate that BTHC does not fit as well as DEHP in DMPC monolayers which could help explain the differences observed with regards to the stability of blood cells.
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| 5. |
- Majumdar Svensson, Orpita
(författare)
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Innovative Polymer Hosts for Solid Lithium-ion Battery Electrolytes
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Current electrolytes used in lithium ion batteries are flammable and volatile organic liquids that are fundamentally unstable at the operational voltage of the cells, posing a significant safety risk. A practical approach to get over this obstacle is to substitute the liquid electrolyte solution with a solid (solvent-free) polymer electrolyte (SPE), which is a solution of a lithium salt in a solid polymer matrix. In the past few decades, polyethers, particularly those based on poly(ethylene oxide) (PEO) have been the subject of extensive research as SPEs. However, numerous researchers have noted inherent limits in the overall performance of PEO and other polyether-based electrolytes, driving the search for electrolytes based on alternative types of polymers. A few of those polymers that can be utilized as prospective polymer hosts for future lithium-ion batteries are introduced in this thesis.Organic carbonates are commonly used as liquid electrolytes, therefore their polymeric counterparts, polycarbonates, are suitable as host materials in SPEs. In contrast to PEO, carbonates show weaker coordination with the lithium ion, which consequently results in faster cation transport. In Paper I, we utilize a metal-free catalyst, diphenylammonium triflate (DPAT), to facilitate the ring-opening polymerization of trimethylene carbonate (TMC). This results in a copolymer, poly(trimethylene carbonate)-poly(trimethylene ether) (PTMC-co-PTME), which has a polymer backbone that possesses both carbonate and ether functionalities.In Papers II and III, we evaluate a new family of SPEs based on poly(β-amino ester)s (PBAEs) by employing aza-Michael addition in the presence of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). We use off-stoichiometric multifunctional short chain acrylates and amines as monomers to synthesize crosslinked polymer electrolyte films through a one-step, dual-curing, metal catalyst and solvent free method. We establish that structural changes in the polymer backbone can be easily introduced by varying the monomers and their concentrations, resulting in enhanced ionic conductivities. This methodology generates zero side products, is highly atom efficient and produces free-standing electrolyte films in a single step.The use of additives in electrolytes is one of the most convenient and affordable ways to improve lithium-ion battery performance without requiring significant modifications. In Paper IV, we use the procedure described in Paper II to explore the effects of different measured concentrations of dimethyl sulfoxide (DMSO) as an additive in PBAE-based SPEs. DMSO has a high donor and acceptor number, making it an effective solvating agent for both the anions and cations in the electrolyte.
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| 6. |
- Majumdar Svensson, Orpita, et al.
(författare)
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Poly(β‐amino ester) based solid polymer electrolytes for lithium‐ion batteries
- 2024
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Ingår i: Journal of Applied Polymer Science. - : John Wiley & Sons. - 0021-8995 .- 1097-4628. ; 141:15
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we present the synthesis of poly(β-amino ester)-based solid polymer electrolytes (SPE) from off-stoichiometric acrylate-amine formulations using one-step, catalyst and solvent free aza-Michael addition. By varying the monomers, the pendant functionality of the polymer chain structure could be altered. All synthesized polymers yield freestanding and easy to handle electrolyte films and hence are evaluated as a new class of SPEs. The SPE with 1,4-butanediol diacrylate and propylamine showed the highest conductivity of 1.15 x 10-7 S cm-1 at 30C with 10 wt% lithium bis(trifluoromethanesulfonyl)imide. Because of the presence of the various functional groups in the structure, the polymer chain aids in the movement of both the anion and the cation.
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| 7. |
- Yang, Yifeng, et al.
(författare)
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Weak acidic stable carbazate modified cellulose membranes target for scavenging carbonylated proteins in hemodialysis
- 2020
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Ingår i: Carbohydrate Polymers. - : Elsevier. - 0144-8617 .- 1879-1344. ; 231
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Tidskriftsartikel (refereegranskat)abstract
- Carbazate groups were grafted on the commercial cellulose membrane (CM) to specifically scavenge the carbonylated proteins for hemodialysis. It confirmed that carbazate groups were successfully covalently attached on the CMs by XPS and EDS, and the modified CMs still saved their original morphology and crystalline structures by SEM and XRD. Furthermore, the modified CMs presented favorable physicochemical stability at wide pH range from 2.5 to 7.4. It was also found that the carbazate modified CMs could selectively remove carbonylated proteins from acrolein treated bovine serum albumin (BSA) or ESRD patient's blood serum in PBS buffer. The modified CMs showed the potential to be utilized as the substitute of dialysis membranes in hemodialysis.
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