PMID- 35012038
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20220113
IS  - 2073-4360 (Electronic)
IS  - 2073-4360 (Linking)
VI  - 14
IP  - 1
DP  - 2021 Dec 21
TI  - Dissolution of Silk Fibroin in Mixtures of Ionic Liquids and Dimethyl Sulfoxide: 
      On the Relative Importance of Temperature and Binary Solvent Composition.
LID - 10.3390/polym14010013 [doi]
LID - 13
AB  - We studied the dependence of dissolution of silk fibroin (SF) in mixtures of DMSO 
      with ionic liquids (ILs) on the temperature (T = 40 to 80  degrees C) and DMSO mole 
      fraction (chi(DMSO) = 0.5 to 0.9). The ILs included BuMeImAcO, C(3)OMeImAcO, 
      AlBzMe(2)NAcO, and Bu(4)NAcO; see the names and structures below. We used design 
      of experiments (DOE) to determine the dependence of mass fraction of dissolved SF 
      (SF-m%) on T and chi(DMSO). We successfully employed a second-order polynomial to 
      fit the biopolymer dissolution data. The resulting regression coefficients showed 
      that the dissolution of SF in BuMeImAcO-DMSO and C(3)OMeImAcO-DMSO is more 
      sensitive to variation of T than of chi(DMSO); the inverse is observed for the 
      quaternary ammonium ILs. Using BuMeImAcO, AlBzMe(2)NAcO, and molecular dynamics 
      simulations, we attribute the difference in IL efficiency to stronger SF-IL 
      hydrogen bonding with the former IL, which is coupled with the difference in the 
      molecular volumes and the rigidity of the phenyl ring of the latter IL. The order 
      of SF dissolution is BuMeImAcO-DMSO > C(3)OMeImAcO-DMSO; this was attributed to 
      the formation of intramolecular H-bonding between the ether oxygen in the side 
      chain of the latter IL and the relatively acidic hydrogens of the imidazolium 
      cation. Using DOE, we were able to predict values of SF-m%; this is satisfactory 
      and important because it results in economy of labor, time, and material.
FAU - El Seoud, Omar A
AU  - El Seoud OA
AUID- ORCID: 0000-0003-1683-5953
AD  - Institute of Chemistry, The University of Sao Paulo, Sao Paulo 05508-000, Brazil.
FAU - Kostag, Marc
AU  - Kostag M
AUID- ORCID: 0000-0002-7331-0312
AD  - Institute of Chemistry, The University of Sao Paulo, Sao Paulo 05508-000, Brazil.
FAU - Possidonio, Shirley
AU  - Possidonio S
AUID- ORCID: 0000-0001-6087-4357
AD  - Department of Chemistry, Institute of Environmental, Chemical, and Pharmaceutical 
      Sciences, Federal University of Sao Paulo, Sao Paulo 04021-001, Brazil.
FAU - Dignani, Marcella T
AU  - Dignani MT
AUID- ORCID: 0000-0002-2650-3947
AD  - Institute of Chemistry, The University of Sao Paulo, Sao Paulo 05508-000, Brazil.
FAU - Pires, Paulo A R
AU  - Pires PAR
AUID- ORCID: 0000-0002-4498-6612
AD  - Institute of Chemistry, The University of Sao Paulo, Sao Paulo 05508-000, Brazil.
FAU - Lourenco, Matheus C
AU  - Lourenco MC
AD  - Institute of Chemistry, The University of Sao Paulo, Sao Paulo 05508-000, Brazil.
LA  - eng
PT  - Journal Article
DEP - 20211221
PL  - Switzerland
TA  - Polymers (Basel)
JT  - Polymers
JID - 101545357
PMC - PMC8747519
OTO - NOTNLM
OT  - design of experiments
OT  - effects of temperature
OT  - ionic liquid molecular structure
OT  - molecular dynamics simulations
OT  - silk fibroin dissolution
COIS- The authors declare no conflict of interest.
EDAT- 2022/01/12 06:00
MHDA- 2022/01/12 06:01
PMCR- 2021/12/21
CRDT- 2022/01/11 01:16
PHST- 2021/09/02 00:00 [received]
PHST- 2021/12/09 00:00 [revised]
PHST- 2021/12/16 00:00 [accepted]
PHST- 2022/01/11 01:16 [entrez]
PHST- 2022/01/12 06:00 [pubmed]
PHST- 2022/01/12 06:01 [medline]
PHST- 2021/12/21 00:00 [pmc-release]
AID - polym14010013 [pii]
AID - polymers-14-00013 [pii]
AID - 10.3390/polym14010013 [doi]
PST - epublish
SO  - Polymers (Basel). 2021 Dec 21;14(1):13. doi: 10.3390/polym14010013.