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Researcher Sara R. Labafzadeh takes part in the research program FuBio JR2 (Future Biorefinery–Joint Research 2) of Forestcluster Ltd. The goal of the program is to build globally competitive knowledge platforms for the creation of new value chains between wood and markets such as packaging, clothing and performance materials. The work package is led by Ilkka Kilpeläinen from University of Helsinki.
The goal of Sara’s doctoral study is to carry out research on modification of cellulose and pulp. Chemically modification of cellulose can alter its properties and processability which can be further utilized in various fields, e.g. synthetic fibers, films, adhesives and explosives.
Derivatization can be carried out either homogenously or heterogeneously. The challenge for homogeneous modification is that cellulose is insoluble in most common organic solvents. The idea “dissolve first-react later” has limited the use of cellulose as a cheap starting material due to the costly and environmentally unfriendly solvent systems. However, it has been investigated in the first article that acylation of cellulose can be carried out under heterogeneous conditions to obtain highly substituted derivatives. When cellulose or pulp is suspended in dry pyridine and stirred under heating with aliphatic or aromatic acid chlorides, cellulose esters with high degree of substitution are obtained through reactive dissolution. The poor solubility of unmodified cellulose in pyridine is accepted as such and the reaction is started as a heterogeneous mixture. Progress of the reaction makes the product soluble and thus drives the reaction forward. She is currently applying the reactive dissolution strategy to produce other cellulose derivatives such as cellulose carbamates and charged derivatives. In the future, she will also try to design and synthesize new ionic liquids for functionalization of cellulose. “Cellulose is a cheap renewable resource for production of novel biodegradable polymers which can compete with fossil-based ones if researchers can design and build economically feasible and environmentally friendly solvent systems" says Sara.
In 2005, Sara graduated from Mechanical Engineering in Iran. After a few years working in Iran, Sara and her husband decided to continue their education in one of the Nordic countries, since they have heard of high-quality education system in these countries. In 2009, Sara got her master degree in Chemical Engineering in Sweden. Her master thesis deals with production of bioethanol from construction and demolition lignocellulose wastes. She came to Finland in January 2010 to start her PhD studies at University of Helsinki, Laboratory of Organic Chemistry.
When not working, Sara spends time with her husband. She likes swimming and watching movies.
The goal of Ahmad’s doctoral study is to carry out research on Foam Physics. As a part of EffNet modeling Ahmad simulates together with David Vidal from FPInnovations in Canada the rheological properties of nano-fibrillar cellulose suspensions. They intend to apply similar simulation methods later to foam-fibre systems.
The bubble size distribution of foam as a function of many parameters was determined in his first article. In the same article, the pore size distribution was investigated also. The size of these pores is affected by the sizes of the bubbles in the foam. Overall, pore size distribution is more strongly affected by the fibre type than by small changes in bubble size distribution.
Foam forming is an interesting new technology to make paper-like materials. This research shows an important interaction between added fibers and foam. Foam forming leads to many positive effects. The fibres inside the foam are locked between the foam bubbles, and thus do not flock during transportation. This provides better formation and allows the usage of higher consistency stock. "Foam physics is a new physics. I would like to investigate the fundamental phenomena related to foam forming" says Ahmad.
In 2011, Ahmad graduated from Al-Balqa Applied University in the Hashemite Kingdom of Jordan. His Master's thesis considers nuclear and radiation physics. He came to Finland last autumn to start his PhD studies at VTT graduate school.
When not working, Ahmad likes to swim and going to sauna to relax.