Development And Capability Of Antifungal Military Fabrics

Superficial mycosis is the infectious skin disease with the highest prevalence in the population.According to surveys,the prevalence of superficial fungal diseases in various countries in the world can reach 20%-25%,causing serious medical waste and economic losses,and bringing huge economic and psychological burdens to patients.Compared with ordinary people,soldiers suffer lots of training which leads to a warm and humid environment of the skin,thus providing an environment for the growth and reproduction of fungi,and are more susceptible to the invasion of pathogenic fungi.The prevalence of superficial fungal diseases in the military is as high as 60%,which is 42%-58%higher than other occupations,seriously affecting the quality of military training,and even causing non-combat attrition in severe cases.In view of this,this paper uses antifungal plant essential oils,adopts microcapsule technology to prepare antifungal microcapsules,and prepares long-acting antifungal military fabrics through antifungal modification of military physical training clothes and combat clothing to satisfy the functional requirements of military personnel for the personal clothing and training clothing for the prevention and treatment of superficial fungal diseases.In this project,the antifungal capability of four typical antifungal essential oils was first carried out to obtain the essential oils with excellent antifungal properties against Trichophyton rubrum and Candida albicans,the most important fungi that cause superficial diseases.Then,the synergistic antifungal effect between different antifungal essential oils was studied to exert their synergistic antifungal properties.Afterward,chitosan-gum arabic antifungal microcapsules（CS-GA microcapsules）were prepared using chitosan（CS）and gum arabic（GA）as wall materials by complex coacervation method.On this basis,the chitosan-gum arabic-silica double-layer microcapsule（CS-GA-Si O₂ double-layer microcapsules）were further prepared by the hydrolysis of tetraethyl orthosilicate.Finally,the CS-GA antifungal microcapsules and CS-GA-Si O₂ double-layer microcapsules were added to the army’s military physical training clothes and combat clothing to prepare long-lasting antifungal military fabrics that suit the military.The specific research content and conclusions of this paper are as follows:（1）The minimum inhibitory concentration（MIC）and fractional inhibitory concentration index（FICI）of four typical antifungal essential oils of Cnidii Fructus,Sophora flavescens,Scutellaria baicalensis,and Dictamnus dasycarpus were first tested by doubling dilution method and microdilution checkerboard techniques to evaluate their antifungal properties.And the synergistic antifungal effect of Cnidii Fructus and Sophora flavescens were studied using filter paper sheet method.The two were compounded in different volume ratios,and the optimal compounding ratio was determined to be 2:1.（2）Using the complex coacervation method,chitosan and gum arabic as wall materials,the optimal emulsification process and preparation process of CS-GA microcapsules were explored through single factor experiments and response surface experiments.The best emulsification process was as follows:the homogenization speed was 8000rpm,the emulsification time was 3min,and the amount of emulsifier was 2.5%.According to the result of the response surface experiment,the best parameters were as follows:the mass ratio of chitosan and gum arabic was1:5.92,the core wall ratio was 1:1.12,and the reaction p H was 4.78 with the estimated embedding rate 72.25%.Some changes were done according to the actual operation,with the embedding rate of CS-GA microcapsules 71.86%and the oil content 46.59%.To improve the strength of CS-GA microcapsules and make them suitable for military combat clothing,a layer of Si O₂ was synthesized based on CS-GA microcapsules by TEOS hydrolysis to prepare CS-GA-Si O₂ double-layer microcapsules.The results showed that when the amount of TEOS was 4 m L,the synthesized double-layer microcapsules has the best performance,and the oil content was41.70%.（3）The successful preparation of CS-GA microcapsules and CS-GA-Si O₂ microcapsules was proved by SEM,TEM,TGA,FTIR,and other testing methods,which also proved the successful coating of compound essential oils.The sustained-release experiments of the two microcapsules at 37°C found that the release rates within one month were 35.53%and 35.08%,respectively.These indicated the long-term antifungal function.（4）CS-GA microcapsules were coated onto military physical training clothes by padding method,the best finishing process was as follows:the concentration of microcapsules was 40g/L,the concentration of citric acid was 40 g/L,and the baking process was 120℃,3 min.SEM images of the fabric showed that the microcapsules penetrate deep into the fiber gap and are tightly combined with the fabric.Besides,the antifungal rates of the finished fabric against Candida albicans and Trichophyton rubrum were 96.7%and 92.6%,respectively.Then,the release of essential oils from military physical training clothes under different sweat volumes was tested,and found that the release of essential oils was different according to the different sweat volumes during training,and the release mechanism followed the Ritger-Peppas kinetic model.After soaking in sweat for 24 h,38.8%of the essential oil was released,and the antifungal rates against Candida albicans and Trichophyton rubrum were 79.9%and 75.27%,respectively,which showed excellent sweat durability.After 20 times of washing,the antifungal rate against Candida albicans was 73.24%and 73.26%against Trichophyton rubrum,which satisfied the requirements of the national standard for the antifungal rate of fabrics（greater than 60%）.（5）In order to improve the loading rate of microcapsules on combat clothing and enhance the antifungal function of the fabric,the fabric was pretreated with ultraviolet light,and then the combat clothing was modified with lipase to enhance the active site on the fiber surface.The optimal preparation conditions were obtained:UV pretreatment time was 2 h,lipase concentration was 2 g/L,lipase treatment time was 6 h,and enzyme treatment temperature was30℃.The enzyme-modified combat clothing was finished using different concentrations of CS-GA-Si O₂ microcapsules,and it was found that when the concentration of CS-GA-Si O₂microcapsules was 50 g/L,the inhibition rates of the combat clothing against Candida albicans and Trichophyton rubrum were 96.17%and 96.02%,respectively.（6）The evaluation of the release performance of essential oils under different friction conditions showed that CS-GA-Si O₂ microcapsules showed better strength under the action of force.After 50 times of friction（1000 mesh sandpaper）,the release of essential oils was 24.9%,which was 30.6%less than that of CS-GA microcapsules under the same action.And the amount of essential oils released from the fabric was different under the same friction times with different pressure,which confirmed that CS-GA-Si O₂ microcapsules could regulate the release with the increase of training intensity.After friction,the antifungal rate against the two fungi was 75.53%and 74.93%,respectively.After 30 times of washing,the antifungal rate against Candida albicans and Trichophyton rubrum was 50.59%and 70.4%,respectively,which presented excellent washing resistance.