Self-healable and pH-sensitive high-strength water-soluble chitosan/chemically cross-linked polyvinyl alcohol semi-IPN hydrogel.

A kind of novel unique semi-IPN was formed through facile radical cross-linking reaction between PVA-based macromonomer (PVAM) and acrylic acid (AA) in the presence of water-soluble chitosan (WSC). WSC, PVAM and AA were dissolved in distilled water, mixed homogeneously and initiated with potassium persulphate to perform the reaction. WSC was well distributed within the chemical network, which enabled the hydrogen bonding to be formed between part of amino groups on WSC chain and some carboxylic groups on PVA-based gel.

Capability of starch derivative containing azo and carboxylic groups to tune photo-behaviors via LbL-assembly.

Starch-based polyelectrolyte that contained azo and carboxyl groups was prepared and applied to performed layer-by-layer (LbL) assembly with amino starch. The structure of the starch-based polyelectrolyte was characterized with UV-visible spectroscopy and HNMR. UV-visible spectroscopy was also utilized to confirm the assembly characteristic of the starch-based polyelectrolyte.

Formation of multilayer through layer-by-layer assembly of starch-based polyanion with divalent metal ion.

The layer-by-layer (LbL) assembly between metal ion and starch-based anion driven by electrostatic interaction was investigated. Multilayer films were obtained from starch-based derivative containing carboxyl groups (SC) with copper or lead ions. It was found that the concentration of metal ion in aqueous solution decreased with increasing the layers.

Fire-retardant multilayer assembled on polyester fabric from water-soluble chitosan, sodium alginate and divalent metal ion.

Lay-by-layer (LbL) assembly among water-soluble chitosan (WSC), sodium alginate (SA) and copper ion was applied to form polysaccharide-based flame retardant coating on polyester fabric. Thermogravimetric analysis (TGA) results indicated the thermal decomposition temperature of the surface-modified sample was higher than that of the original one, and increased with increasing the layers. Microscale combustion calorimetry (MCC) measurements exhibited that the heat release rate (HRR) values of the samples containing various layers were lower than that of unmodified sample and decreased as increasing layers.

Facile preparation and dual responsive behaviors of starch-based hydrogel containing azo and carboxylic groups.

Starch-based hydrogel containing azo group (SHA) was prepared through radical cross-linking reaction among starch- and PVA-based macromonomers, acrylic acid (AA) and 4-acryloyoxyazobenzene (AHAB). AHAB was prepared through an acylation reaction between acryloyl chloride and 4-hydroxyazobenzene (p-HAB), which was obtained by the diazo coupling reaction between aniline and phenol. The structure of SHA was confirmed with Fourier transform infrared spectrometer, thermogravimetric analysis and UV-Visible spectroscopy.

A facile physical approach to make chitosan soluble in acid-free water.

We changed the situation that chitosan was only dissolved in diluted acid through mild physical treatment. In viewing of the usual methods to modify chitosan are chemical ones, we established the approach by using a water-soluble chitosan derivative as the model polymer. Its water-solubility was modulated via changing the concentration of solution and varying the precipitants.

Formation and cleaning function of physically cross-linked dual strengthened water-soluble chitosan-based core-shell particles.

Facile and mild ionic cross-linking and freezing/thawing technologies were applied to prepare double strengthened core-shell particles by using water-soluble chitosan (WSC), sodium alginate (SA) and poly(vinyl alcohol) (PVA) as starting materials. The aqueous solution contained WSC and PVA was dropped in ethanol to form beads. The beads were converted into WSC/PVA hydrogel particles by being subjected to three freeze/thaw cycles.

Entrapment of carbon dioxide with chitosan-based core-shell particles containing changeable cores.

Water-soluble chitosan-based core-shell particles that contained changeable cores were successfully applied to anchor carbon dioxide. The entrapment capacity of the particles for carbon dioxide (EC) depended on the cores. It was found that EC of the particles contained aqueous cores was higher than that of the beads with water-soluble chitosan gel cores, which was confirmed with thermogravimetric analysis.

Tunable core-shell particles generated from smart water-soluble chitosan seeds.

A chain-like route was presented to create various core-shell particles with soft, aqueous or inorganic cores respectively. Water-soluble chitosan (WSC) gel particles were obtained through gelating the aqueous WSC solution of 0.02 g/mL at its isoelectric point.

Tunable functional hydrogels formed from a versatile water-soluble chitosan.

A versatile water-soluble chitosan (WSC) was applied to construct two kinds of controllable functional hydrogels. Magnetic beads were prepared by physical cross-linking WSC with sodium alginate, soaking particles with ferrous chloride and being subjected to self-oxidation. Magnetic character of the beads was tunable by simply changing the initial concentration of ferrous ions.

Versatile particles from water-soluble chitosan and sodium alginate for loading toxic or bioactive substance.

Versatile hydrogel particles were obtained by cross-linking of water-soluble chitosan (WSC) with sodium alginate (SA) in an acid-free medium. The structure of the particles was investigated with Fourier transform infrared spectra, differential scanning calorimetry and thermogravimetric analysis. These characterization results confirmed that the product was physically cross-linked hydrogel consisted of WSC and SA.

Fabrication of distilled water-soluble chitosan/alginate functional multilayer composite microspheres.

Polysaccharides-based functional microspheres were fabricated under mild conditions. Firstly, magnetic alginate microspheres were prepared by emulsification/internal gelation and acted as substrates. Then the multilayer composite microspheres (MCM) were obtained through the layer-by-layer assembly of the distilled water-soluble chitosan and alginate.

Amphiphilic conjunct of methyl cellulose and well-defined polyvinyl acetate.

Tailor-made conjunct of methyl cellulose (MC) and polyvinyl acetate (PVAc) was synthesized through the combination of reversible addition-fragmentation chain transfer (RAFT) polymerization and thiol-ene click reaction. MC was firstly transferred into unsaturated MC (UMC), and then covalently connected with well-defined PVAc obtained by RAFT polymerization of vinyl acetate. The structure of the conjunct polymer (MCV) was confirmed with Fourier transform infrared spectra (FTIR) and proton nuclear magnetic resonance ((1)H NMR).

Rationalizing the development of biomaterials with a new way of thinking.

The history of biomaterials research is seriously surveyed. It is found that an immutable way of thinking for developing biomaterials is rooted deeply in Western medicine and biology. It is necessary to modify or change the current status of thinking.

A novel starch-based adsorbent for removing toxic Hg(II) and Pb(II) ions from aqueous solution.

A novel effective starch-based adsorbent was prepared through two common reactions, which included the esterification of starch with excess maleic anhydride in the presence of pyridine and the cross-linking reaction of the obtained macromonomer with acrylic acid by using potassium persulphate as initiator. The percentage of carboxylic groups of the macromonomer ranged from 14% to 33.4%.