NOVEL CONCEPT FOR ADVANCED PULP FIBERS BY MODIFICATION WITH HIGHLY ENGINEERED MULTIFUNCTIONAL CELLULOSE DERIVATIVES
Multifunctional cellulose derivatives,containing both stimuli responsive,fluorescence active or reactive functional groups and an amino or ammonium(cationic)moiety,are advanced biopolymers for surface modification of different materials.Cellulose fibers are of particular interest,i.e.,to modify the bulk material with a low amount of such biopolymer derivatives is an efficient and simple way to get advanced pulp fibers.The modification can be done simply in aqueous systems.The novel concept of fiber modification will be discussed based on various examples.Thus,bleached eucalyptus kraft pulp fibers were modified by adsorption of novel multifunctional cellulose derivatives to generate light responsive surfaces.Cellulose backbone was decorated with both(3-carboxypropyl)-trimethylammonium chloride and photoactive 2-(4-methyl-2-oxo-2H-chromen-7-yl)oxy acetate moieties.The adsorption was proofed by UV-Vis spectroscopy,SPR,and ToF-SIMS.The adsorption isotherms followed the Freundlich model and it turned out that the main driving force for the adsorption appeared due to electrostatic and hydrophobic interactions. The modified fibers underwent fast photo-crosslinking under UV-irradiation,as demonstrated by light absorbance and fluorescence measurements,yielding fibers with an increased mechanical stability.To design fluorescent pulp fibers the concept of multifunctional cellulose derivatives was also used,however,the active functional groups introduced were N-(3-propanoic acid)-1,8-naphthalimide and N-(4-butanoic acid)-1,8-naphthalimide.The water-soluble products(additionally modified with cationic moieties)possess a fluorescence emission band with a maximum at 393-398 nm,which is typical for naphthalimides.Thus,the modification of pulp fibers yields products showing blue emission(Figure 1).A further example are pulp fibers(bleached pine kraft pulp)modified with 6-deoxy-6-azido-(3-carboxypropyl)trimethylammonium chloride cellulose that were converted with propargyl amine by click chemistry leading to products with reactive amino moieties.These novel and reactive pulp fibers are carriers for immobilization of biomolecules.As a typical example,glucose oxidase from Aspergillus niger cross-linked with glutaraldehyde was immobilized with glutaraldehyde on the surface of amino functional groups-containing fibers.According to standard assays,the enzyme activity was 906.3 U/g.The results from confocal-and stimulated emission depletion microscopy techniques demonstrated that glucose oxidase does not penetrate the interlayers of fibers.Moreover,amino cellulose derivatives of a broad variety of structures could be synthesized by two-step reactions; namely,by tosylation of cellulose and subsequent nucleophilic displacement reaction with various di-and oligoamines like ethylene diamine and tris(2-aminoethyl)amine yielding 6-deoxy-6-ω-amino alkyl)amino cellulose 1.The novel amino cellulose derivatives show not only interesting protein-like self-aggregation behaviour but also formation of mono-or multilayers on various substrates and thus changing the surface properties irreversibly and significantly.For instance,the dying ability of pulp fibers can be changed and amino group-containing carriers for bioanalytical purposes can be obtained.
Thomas Heinze
Centre of Excellence for Polysaccharide Research,Institute of Organic Chemistry and Macromolecular Chemistry,Friedrich-Schiller-University of Jena Humboldtstraβe 10,D-07743 Jena,Germany
国际会议
第五届制浆造纸新技术国际研讨会(ISETPP)暨第三届国际造纸与环境学术大会(IPEC)
广州
英文
1-2
2016-11-07（万方平台首次上网日期，不代表论文的发表时间）