Lercheperkins8945

We discovered that these modifications were related in terms of the degree of sulfation and the α- or β-linkage of HexNY (Y = SO3- or Ac), and especially that the different linkage of the disaccharide unit is the main factor in modification. In addition, the method based on micro-free-radical reaction and HILIC-FTMS is both effective and sensitive, thus suggesting its broad practical value for the structural characterization and in the biological structure-function studies of GAGs. Blending two biodegradable aliphatic polyesters with complementary bulk properties is an easy way of tuning their final properties. In this work, the ductile poly(butylene succinate) was mixed with polylactide, and as expectable, the blends show improved toughness with sharply reduced strengths. The pristine cellulose nanofibers were then used as the reinforcement for the blends. buy ND646 It is found that most nanofibers are dispersed in the polylactide phase because polylactide has better affinity to nanofibers, and the lower viscosity level of polylactide also favors driving nanofibers into the continuous polylactide phase during melting mixing. In this case, the strength and rigidity losses resulted from the presence of soft poly(butylene succinate) phase are compensated to some extent. To further improve mechanical properties, a two-step approach (reactive processing of blends, followed by the incorporation with nanofibers) was developed. This work provides an interesting way of fabricating fully biodegradable composites with well-balanced mechanical performance. A glycosaminoglycan was isolated from the sea cucumber Holothuria coluber (HcFG). A series of oligosaccharide fragments (dp range 3-11) were prepared from its β-eliminative depolymerized product (dHcFG). Extensive NMR characterization of the oligosaccharides indicated the d-GlcA-β1,3-d-GalNAc4S6S repeating disaccharide backbone was substituted by monosaccharide branches comprising of Fuc2S4S, Fuc3S4S and Fuc4S, linked to O-3 of d-GlcA. For the prevailing Fuc3S4S at nonreducing end of dHcFG, the β-eliminative depolymerization process of HcFG was compared with those of the FGs from Actinopyga miliaris (AmFG, branched with Fuc3S4S) and Stichopus variegatus (SvFG, branched with Fuc2S4S). The result suggested that d-GlcA substituted with Fuc3S4S was more susceptible to depolymerization than that with Fuc2S4S. It might be due to the larger steric hindrance effects from Fuc2S4S on the esterification of GlcA. Biological assays confirmed that the minimum chain length (dp8), regardless of the Fuc branch types, was required for the potent anti-iXase and anticoagulant activities in FG fragments. Cellulose nanocrystals (CNCs) per their twisting structure and high aspect ratio and charged surface property are increasingly receiving great attention in chiral photonic crystal and pigment fabrication. However, the cholesteric mesophases of CNCs is unstable and easily destroyed by the additives with high Mw. In this work, hydroxypropyl cellulose (HPC) and carboxymethyl cellulose (CMC) are incorporated into CNCs for a continuous mesophase transition monitoring. We investigated the effects of HPC and CMC on the properties of CNCs with respect to the morphology, mesophase, rheology, and structure-color properties. Our results showed that the addition of CMC (≥ 1 wt%) prevented the formation of a continuous cholesteric phase but resulting in a fast gelation due to the strong repulsion between CMC and CNCs. Alternatively, the cholesteric phase was well-preserved in the CNC/HPC in which HPC ( less then 10 wt%) served as an efficient tuner of phase transition, color hue and rheology properties. This work discussed the preparation of Ag nanoparticles (AgNPs) and AgNPs impregnated sub-micrometer crystalline jute cellulose (SCJC) particles using a green synthetic bioreduction method. The ultimate nanocomposite particles were named as SCJC/Ag. The crystalline structure of AgNPs was maintained in SCJC/Ag nanocomposte particles. The catalytic efficiency of SCJC/Ag nanocomposite particles were evaluated for the degradation of congo red (CR) and methylene blue (MB) using NaBH4 as reducing agent. A complete degradation of 20 mL of each CR (0.1 mM) and MB (0.05 mM) dye solution was achieved within 14 min when 0.005 mg mL-1 of SCJC/Ag nanocomposite particles was employed. SCJC/Ag nanocomposite particles also exhibited moderate antibacterial activities against Staphylococcus aureus, Escherichia coli, Shigella dysenteriae and Shigella boydii and the results were comparable with those of the reference AgNPs. SCJC/Ag nanocomposite particles were the most effective against Escherichia coli (E. coli) with minimum inhibitory concentration of 0.014 mg mL-1. A novel bio-based flame retardant, ammonium phosphate starch carbamates (APSC) was synthesized from starch, phosphoric acid and urea to achieve better thermal stability and char formation. Flame retardant expandable polystyrene foams (EPS) were prepared by coating method with APSC. The fire resistance evaluation of EPS composites by limiting oxygen index (LOI), vertical burning (UL-94) and cone calorimeter tests indicated that the addition of 47 wt.% of APSC enhanced the LOI from 17.6%-35.2%, with V-0 rating in UL-94, and decreased the peak heat release rate from 666 kW/m2 to 316 kW/m2. Moreover, the total smoke production was also sharply decreased from 70 m2 of pure EPS to 17 m2. By the presence of APSC, the substantial char formation prevented the heat and oxygen transfer, and interrupted the releasing of flammable products, thus protecting the EPS foam from burning. Cellulose nanocrystals (CNC) were prepared using acid hydrolysis of cellulose fiber. The CNC modified topo-chemically by grafting of bulky cholesterol moieties which changed subsequent morphology, thermal behavior, lyotropic crystalline properties, and host-guest release behavior. Bond formation between the cellulose nanocrystals surfaces and cholesterol was confirmed by FT-IR and solid-state NMR. The product indicated strong hydrophobic characteristics with an ordered chiral nematic self-assembly. This novel biomaterials were exploited through uptake of folic acid as part of a preliminary host-guest system. The guest molecule released as a function of physiologically relevant pHs was examined.