分子筛型声学增强材料的储存耐候性能

Storage Weathering Resistance of Zeolitic Acoustically Enhanced Materials

研究了湿度和有机物小分子等储存耐候条件对声学增强材料谐振频率偏移值的影响,探讨了由不同硅铝比分子筛组成的声学增强材料在不同湿度及有机物小分子气氛中储存后的谐振频率及偏移值的变化规律.研究结果表明,由既定硅铝比分子筛组成的声学增强材料在25℃/50%相对湿度(RH)和25℃/95%RH条件下储存后,其谐振频率偏移值未发生明显变化.氮气吸附实验结果表明,25℃下氮气分子占据了较少的比表面积,水分子的存在不影响声学增强材料对氮气分子的吸附.在25℃/50%RH条件下放置后,声学增强材料在25℃/95%RH条件下吸附的水分子会逐渐脱附.声学增强材料在不同种类有机物小分子气氛中储存后,其谐振频率偏移值呈不同的变化趋势.对于尺寸较小的有机物小分子,由于存在可逆吸附,声学增强材料的谐振频率偏移值未有明显变化;对于尺寸较大或具有小尺寸端基基团的有机物小分子,由于存在嵌入式吸附,声学增强材料的谐振频率偏移值明显降低.

In this work,the effects of different humidity and organic compounds on resonance frequency offsets(RFOs)of acoustically enhanced materials(AEM)were studied.Undergoing 25℃/50%relative humidity(RH)or 25℃/95%RH storage,coexisting with organic compounds,the changes of RFOs of AEM,composed of zeolite with various silicon-aluminum ratios(SAR),were comprehensively discussed.The results showed that for the AEM composed of zeolite with a specialized silicon-aluminum ratio,the RFOs did not change significantly,after 25℃/50%RH and 25℃/95%RH storage.The results of the nitrogen adsorption experiment at 25℃/50%RH and 25℃/95%RH showed that nitrogen molecules occupied only a small part of the specific surface area at 25℃,and the presence of water molecules did not affect the adsorption of nitrogen molecules.The water molecules adsorbed at 25℃/95%RH will gradually desorb after standing at 25℃/50%RH.After coexisting with different types of organic compounds,the RFOs of AEM had different trends.For organic compounds with small size,with partially reversible adsorption,the RFOs of AEM did not change significantly;for organic compounds with larger size or terminal groups of smaller size,because of inserted adsorption,the RFOs of AEM were significantly reduced.