Chitin nanofibrils/chitosan glycolate composites as wound medicaments

Enhancement of nitrogen release properties of urea–kaolinite fertilizer with chitosan binder

“…Chitosan is widely used to produce controlled release materials in various fields, particularly in controlled release fertilizer (CRF) manufacturing. [9,10] Chitosan can be successfully processed by a lot of chemical reactions because of its hydroxyl and amino groups. [11] The intercalation of kaolinite by urea has been studied in numerous works.…”

Chitin-chitosan nanocomposite gels: reinforcement of chitosan hydrogels with rod-like chitin nanowhiskers

“…[7][8][9][10][11][12][13]15,16 The widths of these rod-like microcrystals, commonly referred to as nanocrystals or nanowhiskers, are similar to those of their original microfibrils, whereas their lengths are reduced to 100-200 nm for microfibrils obtained from higher plants, and 1-2 mm for those from tunicins and algaes. 6 The colloidal suspensions of nanowhiskers are typical liquid crystals, showing strong flow birefringence under polarized light 11 and spontaneous formation of chiral nematic 7,10,13 or nematic 8 ordering.…”

“…3 Values of the crystal modulus were reported as 41 GPa for a-chitin 19 and 150 GPa for b-chitin. 20 As these nanowhiskers are anisotropic nanoparticles with extremely high modulus and strength along their long axes, their utilization as fillers for nanocomposites, that is, composite materials with internal nano-ordered structures, has been widely investigated, [2][3][4]15 since the pioneering report by Favier et al 21 In addition to their high strength, the polysaccharide nanowhiskers have several useful advantages in comparison with conventional inorganic fillers, including facile chemical modification via surface hydroxyl or primary amino groups, and high degree of biodegradability. Although some of the previous studies 20,21 have employed nanocomposite films in which nanowhiskers were dispersed without directional order, more recent studies have produced several new types of nanocomposites, including an electrospun non-woven mat of poly(vinyl alcohol) containing cellulose nanowhiskers, 22 and a drawn poly(vinyl alcohol) fiber in which cellulose whiskers are uniaxially oriented.…”

“…Several recent studies 15,27,28 have enabled preparation of hydrogels reinforced with cellulose nanowhiskers. A combination of chitin nanowhiskers and chitosan for preparation of nanocomposite gels will be promising for utilization of cationic tough gels for antimicrobial applications, as well as a starting material having many primary amino groups as reaction points for subsequent introduction of other chemical moieties.…”

“…A combination of chitin nanowhiskers and chitosan for preparation of nanocomposite gels will be promising for utilization of cationic tough gels for antimicrobial applications, as well as a starting material having many primary amino groups as reaction points for subsequent introduction of other chemical moieties. Besides a study on surgical gels containing chitin nanofibrils, 15 such a chitosan/chitin nanowhisker gel does not seem to be realized, probably because the basic cross-linking conditions used for preparation of celluose nanocomposite gels will result in significant aggregations of both chitosan molecules and chitin nanowhiskers. In the present study, a modified (blocked) isocyanate cross-linker, with two isocyanate groups blocked with sulfonate counterions to enhance stability in an aqueous environment, was used for preparation of a nanocomposite network of chitosan and chitin nanowhiskers.…”