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The purpose of this paper is to analyze the effects of treatments using chitosan in different degree of deacetylations (DDs) on thermophysiological comfort properties of nylon 6,6/elastane pressure garments using a large skin model hot plate instrumentation to prevent infection and excess sweating during burn scar management for future designs.

Chitosans in different DD (DD 70, DD 81 and nylon 6,6/elastane fabrics in different structures, then the total DD 90) are treated with thermal resistance (R_ct) ((°ΔC)(m²)/W), total heat loss (Q_t or THL) (W/m²), apparent total evaporative resistance ( R e t A ), ((ΔkPa)(m²)/W), apparent intrinsic evaporative resistance ( R e f A ), ((ΔkPa)(m²)/W) and total insulation values (I_t) (clo) were analyzed using the large skin model hot plate instrumentation in comparison with untreated control samples. Antimicrobial activities, washing tests and moisture regain properties were also evaluated.

It is found that chitosan DDs have a significant effect on thermophysiological comfort properties of nylon 6,6 fabrics. A small but statistically significant decrease was observed in thermal resistance (R_ct) (Tog) and isolation (I_t) (clo) properties for higher chitosan DDs and for higher chitosan concentrations for all fabric samples after each treatment. Antimicrobial activity showed a small but statistically significant decrease for all samples with the increase of DD and fabrics treated with lower DD 70 of chitosan showed better antimicrobial activity for all samples. Additionally, fabrics treated with higher DD’s exhibited higher moisture regain.

Treatments with chitosan in different DD and in different concentrations impact the heat and moisture transfer properties of nylon 6,6 fabrics significantly. It is a reference to evaluate the thermophysiological comfort properties of pressure garments for future designs using dry and sweating skin tests while imparting antimicrobial activity with chitosans in different DDs.

The purpose of this paper is to synthesize chitosan, N-octyl chitosan (NOCh) and carboxymethyl chitosan (CMCh) derivative from prawn shell wastes and identify their applications as modifiers on cellulosic fibres, jute and cotton, to develop quality textile fibres.

Chitosan was obtained by deacetylation of chitin. NOCh was obtained by reductive amination of chitosan. Water-soluble CMCh was prepared by reacting chitosan with monochloroacetic acid in aqueous alkaline media at ambient conditions. Chitosan, NOCh and CMCh were applied on cellulosic fibres, and structure and physico-chemical characteristics of chitosan derivatives and modified fibres were investigated and analysed.

The molecular weight, degree of deacetylation and ash content of prepared chitosan were 1,39,958 Da, 85 and 2.33 per cent, respectively. The moisture content, water holding capacity and total nitrogen content were above 10, 450 and 6.5 per cent, respectively. Average degree of substitution of CMCh was 0.82 as determined by titrimetric analysis. Fourier transform infrared spectroscopy (FTIR) spectra showed characteristic peaks of carbonyl group at 1,659 cm⁻¹, –NH2 at 1,600 cm⁻¹, symmetric stretching of C-H in the methyl group at 1,520 cm⁻¹ and carboxylic group at 1,737 cm⁻¹. Thermograms showed moderate thermal stability in treated fibres compared to untreated fibres. Surface morphology of the modified fibres exhibited smoother surface due to the absorption of chitosan, NOCh and CMCh.

Modification of jute and cotton by sorption of NOCh and CMCh introduced new functional groups on the fibre surface with chemical bonding, which was confirmed by FTIR. Surface morphology of the fibres was carried out by scanning electron microscopy. As the modified fibres also showed good dyeability and colour fastness as well as other properties, the chitosan derivatives as a textile modifier would be helpful to avoid synthetic petroleum-based chemical modifiers as well as to manage the environmental pollution from prawn shell waste and other toxic chemicals.

The aim of the paper is to shed light on the use of chitosans and chitooligosaccharides as biopreservatives in various foods animal. Foods of animal and aquatic origin (milk, meat, fish, eggs, sea foods, etc) become contaminated with a wide range of microorganisms (bacteria, molds and yeasts) during harvesting, transporting, processing, handling and storage operations. Due to the perishable nature of these foods, their preservation is of utmost importance. Though many synthetic chemicals are available, yet their use is quite restricted due to their hazardous effects on human health.

Within the domain of food industry, traditionally chitosan is used for biopreservation of foods, which is well known for its nutritional and medicinal properties in human nutrition. However, chitooligosaccharides also possess a number of nutraceutical and health promoting properties in addition to their preservative effect and shelf-life extension of foods. In this study, the comparative effects of both chitosan and chitooligosaccharides on preservation of foods of animal and aquatic origin have been summarized.

Though chitosan has been extensively studied in various foods, yet the use of chitooligosaccharides has been relatively less explored. Chitooligosaccharides are bioactive molecules generated from chitosan and have several advantages over the traditional use of chitosan both in food products and on human health. But unfortunately, little or no literature is available on the use of chitooligosaccharides for preservation of some of the foods of animal origin. Notable examples in this category include cheese, beef, pork, chicken, fish, sea foods, etc.

This paper focuses on the effects of chitosans and chitooligosaccharides on the processing and storage quality of foods of animal and aquatic origin, which offers a promising future for the development of functional foods.

The purpose of this investigation was to study the inhibitive action and adsorption potential of chitosan extracted from Archachatina marginata snail shells on the corrosion of plain carbon (mild) steel in acid media.

Weight loss and thermometric methods were used during this investigation. Characterization of the obtained chitosan was accomplished with Fourier transform infrared spectroscopy analysis. The effects of parameters influencing the inhibition process (concentration and temperature) were evaluated, and the sorption isotherms and thermodynamic parameters were derived.

The results obtained showed that chitosan has good inhibition potential with an efficiency of 93.2 per cent. The inhibition efficiency decreased with an increase in temperature but increased with increasing concentration of chitosan. Test results best fitted the Langmuir Isotherm with a correlation coefficient (R2) of 0.999. The thermodynamic parameters studied reveal that the adsorption of chitosan on the surface of mild steel is spontaneous.

The paper fulfills an identified need in finding solutions to the problems of metal corrosion using agricultural wastes.

The purpose of this paper is to prepare anionically surface‐modified organic pigment/binder ink jet inks for printing on chitosan‐pre‐treated silk fabrics.

Anionically surface‐modified organic pigment/binder ink jet inks were prepared in four colours (cyan, magenta, yellow and black). The pigment‐to‐binder ratio was controlled at 1:6.4 for the cyan, magenta and yellow inks, and 1:3.4 for the black ink. Ink formulations (by weight) were assembled and mixed as follows: 8 per cent pigment dispersion, 10 per cent diethylene glycol, 12 per cent glycerol, 5 per cent urea, 10 per cent polyacrylate emulsion binder and 55 per cent deionised water. They were characterised in terms of their particle size, zeta‐potential, particle morphology, viscosity, surface tension and pH. The inks were printed onto silk or the chitosan pre‐treated silk fabrics using a piezo‐type ink jet printer. The fabrics were then heat cured and analysed for the effect of chitosan pre‐treatment on colour gamut, wash fastness and crock fastness.

The formulated ink jet inks yielded an acceptably good ink jetting reliability, one‐year stability and printability. The chitosan pre‐treated silk fabrics gave a wider colour gamut and colour saturation than the non‐treated one. Crock fastness and wash fastness of the chitosan pre‐treated fabrics were relatively better than those of non‐treated fabrics.

The surface‐modified pigments are transparent and thus their inks printed on the chitosan pre‐treated fabrics produced slightly low K/S values of cyan, magenta, yellow, and black colours because the limited chitosan concentration in the pre‐treatment is controlled by its solubility in acidic solution. The higher loading of chitosan pre‐treatment gave higher K/S values and a stiffer touch of the fabrics.

The water‐based pigmented inks having the sulphonate group on the pigment surface can be printed on the fabric surface pre‐treated with chitosan molecules which have the protonated amino groups to give good colour appearance. It is anticipated that this type of ink can be applied to any textile surface which has been pre‐treated with the protonated chitosan.

The modified organic pigments having the sulphonate group on their surface can be used to produce novel water‐based ink jet inks which can print on the chitosan pre‐treated silk fabric. Ionic interactions between the sulphonate group of the pigment and protonated amino groups of chitosan in conjunction with polyacrylate binder enhance colour strength, widen colour gamut and chroma, and produce good adhesion for fabric operational properties such as wash fastness and crock fastness.

In the past decade, the biopolymeric properties of chitosan (CH) have been largely exploited for various applications. This paper aims to study the use of CH in its nanoform, i.e. as nanofibers blended with polyvinyl alcohol (PVA) for various antimicrobial applications in detail. In particular, their ability toward bacterial growth inhibition, in vitro drug release and their biocompatibility toward tissue growth have been investigated in detail.

Electrospinning technique was adapted for depositing CH/PVA blended nanofilms on the silver foil under optimized conditions of high voltage. Three different concentrations of blended nanofiber samples were prepared and their antimicrobial properties were studied.

The bead diameter and average diameter of blended nanofibers increase with CH concentration. Antibacterial activity increases as CH concentration increases. Increased hydrophilicity in CH-enriched samples contributes to a higher drug release profile.

To the best of the authors’ knowledge, chick chorioallantoic membrane assay analysis has been carried out for the first time for CH/PVA films which shows that CH/PVA blends are biocompatible. CH after being converted as nanoparticles exhibits higher drug release rate by in vitro method.

This study aims to scrutinize the efficacy of chitosan (CT) on cardio-lipotoxic responses elicited by a high-fat diet (HF).

Thirty-six male Wistar rats were distributed across six groups (n = 6): normal diet (ND), HF, ND-5%CT, HF-1%CT, HF-3%CT and HF-5%CT, for seven weeks. Blood and cardiac tissues were processed for biochemical, immunohistochemical and histopathological analyses.

Ingestion of HF induced hyperlipidaemia and lipid accumulation, leading to increased body and heart weight by 70.5% (p < 0.0001) and 124% (p = 0.0021), respectively, compared to ND-groups. Cardiac damage markers (creatine kinase, lactate dehydrogenase and malondialdehyde) were higher in the HF-group compared to control rats. Also, atherogenic and coronary risk indices were significantly elevated by 155% (p = 0.0044) and 174% (p = 0.0008), respectively, compared to control rats. Rats fed HF had significantly reduced cardiac antioxidants (superoxide dismutase, catalase and glutathione peroxidase) and elevated expression of NF-κB-p65 and p53 (p < 0.0001) in the cardiac tissues. Histology revealed lipid inclusions in the cardiac tissues of HF-groups. CT (1%–5%) prevented hyperlipidaemia, lipid accumulation, oxidative stress and cardiac damage in HF-fed rats, while greatly improving the histology of the cardiac tissues in HF-fed rats in a dose-dependent manner.

To the best of the authors’ knowledge, this is the first report of the effects of CT against cardio-lipotoxicity elicited by HF diet ingestion. The findings suggest that CT may present a safe therapeutic alternative for managing complications arising from cardio-lipotoxicity.

Chitosan is widely considered as a natural polymer and a diverse finish to impart antibacterial property and enhanced dye uptake of textiles. Herein, the authors have investigated the feasibility of using chitosan/starch blend as a thickener in screen printing of cellulosic fabrics with some natural dyes.

The polymeric blend of chitosan/starch was prepared and used as a thickener for screen printing with three natural dye extracts, namely, Curcuma tinctoria (turmeric), Beta vulgaris (beet) roots and Lawsonia alba (henna) leaves on cellulosic fabrics like cotton and viscose. The viscosity and rheological properties of print paste as a fresh and after overnight shelving were examined. The influence of polymeric blends on cellulosic fabrics' print properties was inspected by determining their colorfastness, rubbing fastness, tensile strength and antibacterial activity.

The results depicted that chitosan/starch blend as printing thickener increased the shade depth with good wet and dry rubbing fastness for all the test natural dyes. The antibacterial activity of resultant printed cellulosic fabrics was found to be satisfactory against broad-spectrum bacterial strains.

This study's outcome is the development of chitosan blend thickeners to print the cellulosic fabrics with indigenous natural dyes.

The authors found no previous report on the synthesis of chitosan-based antibacterial blend thickeners with three distinct natural dyes and their application in screen printing of native and regenerated cellulosic fabrics of cotton and viscose, respectively.

Particles are of the controlled release delivery systems. Also, topically applied olive oil has a protective effect against ultraviolet B (UVB) exposure. Due to its sensitivity to oxidation, various studies have investigated the production of olive oil particles. The purpose of this study was to use chitosan and sodium alginate as the vehicle polymers for olive oil.

The gelation method used to prepare the sodium alginate miliparticles containing olive oil and particles were coated with chitosan. Morphology and size, zeta potential, infrared spectrum of olive oil miliparticles, encapsulation efficiency and oil release profile were investigated. Among 12 primary fabricated formulations, formulations F₅ (olive oil loaded alginate miliparticles) and F₁₁ (olive oil loaded alginate miliparticles + chitosan coat) were selected for further evaluations.

The size of the miliparticles was in the range of 1,100–1,600 µm. Particles had a spherical appearance, and chitosan coat made a smoother surface according to the scanning electron microscopy. The zeta potential of miliparticles were −30 mV for F₅ and +2.7 mV for F₁₁. Fourier transform infrared analysis showed that there was no interaction between olive oil and other excipients. Encapsulation efficiency showed the highest value of 85% in 1:4 (olive oil:alginate solution) miliparticles in F₁₁. Release study indicated a maximum release of 68.22% for F₅ and 60.68% for F₁₁ in 24 h (p-value < 0.016). Therefore, coating with chitosan had a marked effect on slowing the release of olive oil. These results indicated that olive oil in various amounts can be successfully encapsulated into the sodium-alginate capsules cross-linked with glutaraldehyde.

To the best of the authors’ knowledge, no study has used chitosan and sodium alginate as the vehicle polymers for microencapsulation of olive oil.

The purpose of this study is to prepare composite of chitosan-modified smectite clays consisting of montmorillonite and saponite clay minerals and their urea adsorption–desorption study. Prepared materials were designed for slow-release fertilizer application.

Preparation of the composites was conducted by a simple intercalation of chitosan solution and clay suspension followed by hydrogel beads formation. Physicochemical characterization of materials was performed by X-ray diffraction, gas sorption analysis by using Brunauer–Emmett–Teller surface areas and pore volume, water absorbency and Fourier transform-infrared. Urea adsorption and desorption studies of prepared materials were conducted by using batch method, and the adsorbed and desorbed urea content was analyzed by using high-performance liquid chromatography method.

The results revealed that the composites have higher absorptivity and lower absorptivity toward urea from and into water solution compared to raw clay minerals. Adsorption capacity and slow desorption rate of urea from the composites suggested the potential application of the composites as slow urea-releasing agent.

There are many papers that study the formation of chitosan-clay composites, but the study on the urea adsorption–desorption properties based on chitosan-smectite minerals have not been reported. Intensive study related to physicochemical properties and its related kinetics study is an important basic finding for further applications.