Effect Of Inorganic Compound Sol-gel On Mildew Resistance Of Bamboo Scrimber

Bamboo scrimber is one of the bamboo products,which has excellent mechanical performance,high utilization,and the wide application,and exhibits great prospects for further development.However,bamboo is highly prone to mildew,bluestain,worm-eatern and rotten in storing,transportation and use of the process due to its abundant nutrients,such as carbohydrate,starch,protein and so on.These severely affect the utilization of bamboo scrimber.Therefore,anti-mold bamboo product is one of the key technologies for the development of the bamboo industry.sol-gel would be a useful method to prepare an anti-mold agent with superior efficient mildew resistance and anti-leachability.In the process of bamboo scrimber preparation,the copper boron and phosphoric acid compound anti-mold agent fixed by silica-alumina sol was introduced.The paper focused on analyzing the effect of four factors on the performance of anti-mold of bamboo scrimber,which included phosphoric acid,silica-alumina sol,boric acids and copper salts.Bamboo scrimber mildew resistance,distribution of anti-mold agent in the material and the change of surface chemical structure were investigated.The main research results were summarized as follows:(1)The preparation of boron anti-mold agent,copper anti-mold agent,phosphate aluminum sol and silica alumina sol was discussed by using single factor test.The aim was to studying the effect of copper and boron anti-mold agent with different concentration,the mass ratio of phosphorous aluminum sol and silica aluminum sol in controlling mould and stain fungi.And further,better concentration of copper salt and boric acid was established respectively with 2%and 0.7%,and a better mass ratio of phosphate aluminum sol and silica alumina sol was determined respectively with 1:1 and 10:1.It was found that the sensitivity of various kinds of anti-mold agents to fungi was different.And antimicrobial ability had limitations.(2)In consideration of the disadvantages of single anti-mold agent,design experimental scheme which included four systems as follows:copper-boron,phosphorus-aluminum,silicon-aluminum and silicon aluminum phosphate composite system by using two-step treating charring bamboo bundle.To discuss the influence on its performance and the coMParison of the mildew resistance and anti-leachability of four types of anti-mold agent,it was found that charring bamboo bundle treated with copper-phosphorus-boron compound combined with silica-alumina sol is the best way,the mean control efficacy of three types of mold which including Aspergillus niger V.Tiegh.,Trichoderma viride Pers.ex Fr.and Penicillam citrinum Thorn,can reach 94.42%,and also the control efficacy of Botryodiplodia theohromae Pat.can reach 81.25%.What's more,its'anti-leachability was strengthened.The microstructure of the sample was considered to be coated by a layer of film.(3)Analyzing the effect of four factors on the performance of anti-mold bamboo scrimber by using response surface analysis,the four factors include the mass fraction of phosphoric acid,silica-alumina sol,boric acids and copper salts.The preparation technology of anti-mold was optimized in terms of the mean control efficacy of three types of mold and bluestain fungus.And further,the better mass fraction of raw materials was considered as follows:phosphoric acid,silica-alumina sol,boric acid and copper salt were 1.53%,20.81%,1.66%and 0.99%respectively.The control effect of bamboo scrimber prepared can reach 91.75%under this condition.Apparently,mildew resistance of bamboo scrimber was significantly increased.What more,it has superior mechanical properties which the elastic modulus and static bending strength are 10560.92 MPa and 103.06 MPa,and anti-leachability.To study the anti-mold mechanism of bamboo scrimber,it was found that the structure of bamboo scrimber before and after the anti-mold treatment had obvious differences by using SEM-EDS,FTIR,XPS,XRD and BET analysis.A layer of inorganic membrane was formed in the bamboo scrimber treated with the anti-mold agent of copper boron compound fixing to silica-alumina sol,in the form of hydrogen bond or bonds connected to the fiber surface,or in the form of physical filling,which can block the invasion of the mold effectively,and the antimicrobial activity of copper and boron element effective fixation in material.Thus,inorganic anti-mold agent and bamboo fiber can establish an effective good antibacterial system.