Dimethylformamide dmf

Ferrous sulfate, ammonium ferric (III) sulfate dodecahydrate ((FeSO₄⋅7H₂O; >99.0%) and (NH₄)Fe(SO₄)₂⋅12H₂O; >99.0%, respectively), epichlorohydrin (epi; >99.0%), chitosan (Degree of Acetylation (DA): greater than 75%) (CHI), sodium hydroxide pellets (>99.99% for pH adjustment), sodium ethoxide (C₂H₅ONa) solution (50%), thiourea (CH₄N₂S; 99%), diethyl malonate (C₇H₁₂O₄; 99%), glutaraldehyde (C₅H₈O₂; 25% in H₂O) and potassium dichromate (K₂Cr₂O₇) were supplied by Sigma Aldrich (Merck, Darmstadt, Germany). Acetone (99.9%) and dimethylformamide (DMF; 99.9%) were purchased from Chron Chemicals (Qionglai, China). Other chemicals were obtained from Prolabo (VWR, Avantor Group, Fontenay-sous-Bois, France), which are used without further purification.

All chemicals used in this study were analytical grade. Epichlorohydrin (EPI), ferrous sulfate (FeSO₄·7H₂O), chitosan (Chit, degree of acetylation, DA: <25%), ammonium ferric (III) sulfate dodecahydrate ((NH₄)Fe(SO₄)₂·12H₂O), sodium hydroxide, phosphoric acid, Muller-Hinton agar (microbiological growth medium), and dimethylsulfoxide (DMSO) were purchased from Sigma Aldrich (Merck KGAa, Darmstadt, Germany). Uranyl nitrate hexahydrate (UO₂(NO₃)₂·6H₂O) was obtained from Spi Supplies (West Chester, PA, USA). Dimethylformamide (DMF) and acetone were purchased from Chron Chemicals (Qionglai, China). Guar gum (GG) was obtained from Alpha Chemika (Mumbai, Maharashtra, India). Urea was supplied by Chem Lab (Zedelgem, Belgium). Other chemicals are Prolabo products (VWR, Avantor, France) and they were used as received.