Novel high-temperature thermochromic polydiacetylene material and its application as thermal indicator

The design and synthesis of organic high-temperature reversible thermochromic materials is one of the difficult issues in the field of organic chromic materials.In this paper,four diacetylene monomers named DBA-PCDA,TBA-PCDA,DBE-PCDA and TBE-PCDA,each containing multiple diacetylene units,were synthesized from 10,12-pentacosadiynoic acid(PCDA)through the amidation or esterification reactions,using 4,4'-diaminobiphenyl,1,3,5-tris(4-aminophenyl)benzene,4,4'-dihydroxybiphenyl,and 1,3,5-tris(4-hydroxyphenyl)benzene as bridging units.The effects of functional groups that can form hydrogen bond andπ-πinteractions on the solid-state polymerization properties of monomers and the thermochromic properties of the corresponding PDAs were investigated.The results show that only DBA-PCDA and TBAPCDA,which contain functional groups that can form hydrogen bonding interactions,can be polymerized under 254-nm UV irradiation.The corresponding poly(DBA-PCDA)exhibits reversible thermochromic property even heated up to 200℃,showing a potential application in the field of high-temperature thermal indicator above 100℃.This work provides a new perspective to the development of PDA with high-temperature reversible thermochromic property.

Monitoring the Effective Sterilization of Low-Temperature Hydrogen Peroxide Gas Plasma Sterilizers in 58 Hospitals——22 PLADs,China,June 2015-December 2019

Summary What is already known on this topic?Hydrogen peroxide sterilizeation is widely used for luminal devices.However,the low penetrability of the sterilant is of major concern.What is added by this report?This report investigated the effective sterilization of low-temperature hydrogen peroxide gas plasma sterilizers and compared the applicability of different biological monitoring methods based on medical luminal devices.

Preliminary Study of Pulsed Ultraviolet Technology for Low-Temperature Disinfection

Introduction:To explore the feasibility of pulsed ultraviolet(UV)light technology for low-temperature disinfection,a series of experiments were conducted.Methods:Pulsed UV technology’s effectiveness in disinfecting Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli on different carriers were studied under varying temperatures.Results:Under different temperatures and constant radiation illumination(i.e.,distance),the disinfection effect was correlated with irradiation time;among the three carriers,the disinfection effect of cloth sheets was the best,followed by stainless steel sheets,and corrugated paper sheet.The disinfection effect on Gram-negative bacteria Escherichia coli was better than that on Gram-positive bacteria Staphylococcus aureus overall.Discussion:Temperature has a limited effect on pulsed UV disinfection.Irradiation times and carrier types are influencing factors.

Key Points of the Program for Disinfection Technology in Special Places During the Coronavirus Disease-2019(COVID-19)Outbreak

Since January 2020,the coronavirus disease 2019(COVID-19)epidemic has been prevalent throughout China.Disinfection,as an effective measure to cut off routes of transmission,is crucial in addressing epidemics of infectious diseases.To further guide prevention and control of COVID-19 and on-site disinfection nationwide,the Program for Disinfection Technology in Special Places(first edition)has been developed on January 28.