A New Class of Biodegradable Organic Optoelec-tronic Materials:α-Oligofurans

Organic optoelectronic materials have received considerable attention due to their great potentials in electronic devices,such as organic field-effect transistors(OFETs),organic light-emit-ting diodes(OLED)and organic photovoltaic cells(OPV).Besides,their fascinating properties of flexibility,biocompatibility,molecular diversity,low-cost and solution processability bring new opportunities in bioelectronics in the past decade.While almost all known organic optoelectronic materials are obtained from unrenewable fossil resources and nondegradable,a new family of organic optoelectronic materials is now emerging,which can be obtained from green plants and are biodegradable.Meanwhile,they exhibit excellent optoelectronic properties.This review summarized the synthesis and important molecular properties of this new class of biodegradable organic opto-electronic materials:α-oligofurans.Recent progress of furan-based materials and the existing chal-lenges are also discussed to stimulate further advances in the study of this class of materials.

A new PM_(2.5)-based CADR method to measure air infiltration rate of buildings

Air infiltration is an important way to exchange indoor air with outdoors.It significantly impacts energy consumption and air quality of buildings.Fine particles(PM_(2.5))in the outdoor atmosphere environment are a potential natural tracer for the measurement of air infiltration rate,especially in the long term field measurement.In this study,a PM_(2.5)-based method,named as CADR(clean air delivery rate)method,is developed to supplement traditional tracer gas method in order to make routine measurement in realistic environments possible and convenient.An air cleaner is installed indoors to reduce indoor PM_(2.5) concentration.Air infiltration is determined by fitting a model to the decreasing concentration data.Comparison with CO_(2) decay method in four different indoor environments gives a normalized mean error of 19%and a correlation coefficient of 0.80 for this method.This justifies the CADR method as a feasible option to measure air infiltration rate.Although subject to several constraints,the proposed method would facilitate field measurement under realistic conditions by being combined with current tracer gas methods.