Purification of conjugated polymers. Better polymers through HPLC purification and Soxhlet extraction
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Materials chemistry (MPMCN), MSc
Publicerad
2024
Författare
Öhberg, Jessika
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Abstract
The purification of conjugated polymers, specifically the polymer D18, was investigated
using the purification methods of Soxhlet extraction and High-Performance
Liquid Chromatography (HPLC). The objective was to purify D18 from residual Pd
impurities remaining from synthesis and fractionate the molecular weight for lower
dispersity and higher molecular weights. This is crucial for conjugated polymers
like D18, as with robust and effective purification methods, they have a prominent
future as materials extensively used in organic electronic devices such as solar cells.
The purification process has a significant impact on the polymer’s properties, influencing
its electronic and optical performance which highlights the importance of
standardized purification and reproducible results. The study demonstrates that
while Soxhlet extraction was effective in removing low molecular weight fractions,
HPLC proves to be superior in narrowing down the dispersity and reducing palladium
(Pd) content for the polymer D18. The work also investigates the use of
TOF-SIMS for measuring Pd content before and after purification by developing a
calibration curve. Two palladium complexes, Pd(PPh3)4 and Pd2(dba)3 chloroform
adduct, were along with the polymer P3HT used to create calibration curves, with
Pd2(dba)3 showing better performance due to its solubility and stability. Challenges
included potential contamination, suggesting the need for stricter environment protocols
for sample handling. Calculating the Pd content from the calibration curves
underscored the importance of a robust normalization technique to obtain absolute
quantification. This research provides insights into purification methods that can
enhance the performance of conjugated polymers in organic electronic applications
and demonstrates the use of TOF-SIMS as an evaluation method of metal impurities.
Keywords: Conjugated polymers, Purification, Soxhlet extraction, HPLC, TOFSIMS.
Beskrivning
Ämne/nyckelord
Conjugated polymers , Purification , Soxhlet extraction , HPLC , TOFSIMS