Full-Spectrum Driven Antibacterial Coating Based On Phosphorus On Ti Alloy

With the rapid development of modern medicine,many diseases previously called terminal illnesses have been overcome,such as tuberculosis,smallpox,cholera,etc.Many chronic diseases can also be effectively controlled,such as diabetes and hypertension.Thus human's life expectancy has been unprecedentedly improved.However,with the aging of the population structure,the risk of a series of problems such as hard tissue damage has also increased.The prevalence of orthopedics will become higher and higher,with the increasing demand for medical implant materials.Among them,Ti-based implants are widely used as internal implants in clinic,such as orthopedics and orthopedics,due to the small specific gravity,great corrosion resistance,excellent bone conductivity and biocompatibility.Actually,there are always failed cases of implant in clinic.One of the main reasons is bacterial infection on the surface of artificial implants.Although the sterilization requirements are as strict as possible during implantation,the presence of foreign bodies,such as titanium implants,will greatly reduce the number of bacteria required for infection.The bacteria from medical staff,ambient air and the human body,provide the source of infection,and the blood or tissue around the wound provides a wealth of nutrients,making postoperative infections often occur.Today,the main treatment option is to remove the implant for revision and debridement,which will greatly increase the patient's pain and cost.Considering the difficulty of treating implant infections,an effective approach is to cut off the source,that is,to modify the surface of the implant to make it self-antibacterial.In this paper,a chemical vapor deposition(CVD)method is used to construct the coating based on a phosphorus-based photocatalyst,which provides excellent intelligent self-antibacterial properties for medical titanium alloys while ensuring its biological compatibility.This paper discusses in detail the crystal structure and optical properties of the coating,as well as the improvement of its photocatalytic and photothermal properties after compounded with graphene oxide(GO).Moreover,the intelligent-response performance of the hybrid was explored,as well as its antibacterial mechanism,photocatalytic mechanism and biocompatibility.In summary,a series of processes from a new type of phosphorus-based coating to its antibacterial application were investigated.The basic contents of the study as following:1.The construction of a full-spectrum driven P-based photocatalytic coating by CVD method.First,the uniform commercial red phosphorus powder(amorphous red P)is obtained by hydrothermal method and grinding.Then the red phosphorus powder is transformed into a crystal form and deposited on the surface of titanium alloy by CVD.The tested results show that the coating is in the form of an irregular pyramidal array,while the optical property is full-spectrum absorption,which the absorption in the near infrared region is the strongest.Through a detailed analysis of its crystal form,it is concluded that the coating is composed of black phosphorus and another potential new phosphorus..Moreover,it shows good photocatalytic performance that it can produce superoxide anion and singlet oxygen under near infrared light.2.The construction of P/GO hybrid coating by pyrolysis method.In order to improve the photocatalytic performance of the P coating,a layer of graphene oxide was introduced by a pyrolysis method.Its structure,properties and mechanism of the improvement are studied.The results show that the morphology and structure of the hybrid coating has not changed compared to the P coating.It also showed that the photoelectrochemical performance has been greatly improved,the lifetime of the photogenerated electrons becomes longer,and the photocatalytic activity is also enhanced.3.The study on intelligent-response antibacterial performance of P/GO hybrid coating to different light.To explore the antibacterial properties,photo-response antibacterial tests of the coating are performed.The results show that the antibacterial rate of the metal-free coating against10~7CFU/m L of Staphylococcus aureus and Escherichia coli is about 99.9%under irradiation of the simulated sunlight for 20 minutes.Meanwhile,other antibacterial experiments show its good antibacterial effect under visible light and near infrared light.In addition,under the irradiation of LED lights,the coating exhibits good biofilm removal.Besides,the coating also has good hydrophilicity and biocompatibility.The above results show that the coating has a good application prospect in the biomedical field.