Role of porosity on nanofibrous membrane sound absorption properties

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F46747885%3A24620%2F19%3A00007717" target="_blank" >RIV/46747885:24620/19:00007717 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.researchgate.net/publication/335602285_ROLE_OF_POROSITY_ON_NANOFIBROUS_MEMBRANE_SOUND_ABSORPTION_PROPERTIES" target="_blank" >https://www.researchgate.net/publication/335602285_ROLE_OF_POROSITY_ON_NANOFIBROUS_MEMBRANE_SOUND_ABSORPTION_PROPERTIES</a>

DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Role of porosity on nanofibrous membrane sound absorption properties

Popis výsledku v původním jazyce

A thin nanofibrous layer used as a membrane can vibrate at low frequencies due to small interfibrous spaces and planar arrangement that are forced by low-frequency sound waves. Nanofibrous layers of very small thickness having three different surface area densities were manufactured from a polymer solution of PVA using the electrospinning method. Due to resonance at its natural frequency, the membrane is able to absorb sound energy. These unique properties come from the nature of nanofibrous webs, small fibrous diameter, the high surface area of the layer, its inner structure, and inter-fibrous spaces causing high viscous losses inside the material. Optimal rigidity and placement of the membrane facilitate its vibration. Under certain humidity conditions, visible changes in PVA fibrous structure occur, as PVA accumulates fluid in its polymer chains. Thus, the PVA membrane structure (porosity) was controlled in the range of limit values by using different vapor application time. A standard two-microphone impedance measurement tube was employed to measure the sound absorption coefficient of the nanofibrous membranes. Structural properties have been investigated with pore-size assessment, supported by air permeability and airflow resistivity measurements, all covered by Scanning Electron Microscopy. Effects of these parameters on the sound energy dissipation were compared with the sound absorption results and are discussed in this article. It has been observed that the value of membrane`s porosity and resistance to airflow affect its dampening capacities, recognizing that there are additional mechanisms beyond sound absorption of nanofibrous membranes that must be investigated, thus indicating the important role of membrane nanofibrous structure in sound absorption.

Název v anglickém jazyce

Role of porosity on nanofibrous membrane sound absorption properties

Popis výsledku anglicky

A thin nanofibrous layer used as a membrane can vibrate at low frequencies due to small interfibrous spaces and planar arrangement that are forced by low-frequency sound waves. Nanofibrous layers of very small thickness having three different surface area densities were manufactured from a polymer solution of PVA using the electrospinning method. Due to resonance at its natural frequency, the membrane is able to absorb sound energy. These unique properties come from the nature of nanofibrous webs, small fibrous diameter, the high surface area of the layer, its inner structure, and inter-fibrous spaces causing high viscous losses inside the material. Optimal rigidity and placement of the membrane facilitate its vibration. Under certain humidity conditions, visible changes in PVA fibrous structure occur, as PVA accumulates fluid in its polymer chains. Thus, the PVA membrane structure (porosity) was controlled in the range of limit values by using different vapor application time. A standard two-microphone impedance measurement tube was employed to measure the sound absorption coefficient of the nanofibrous membranes. Structural properties have been investigated with pore-size assessment, supported by air permeability and airflow resistivity measurements, all covered by Scanning Electron Microscopy. Effects of these parameters on the sound energy dissipation were compared with the sound absorption results and are discussed in this article. It has been observed that the value of membrane`s porosity and resistance to airflow affect its dampening capacities, recognizing that there are additional mechanisms beyond sound absorption of nanofibrous membranes that must be investigated, thus indicating the important role of membrane nanofibrous structure in sound absorption.

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

10307 - Acoustics

Projekt

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Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

Proceedings of the 26th International Congress on Sound and Vibration, ICSV 2019

ISBN

978-199918100-0

ISSN

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e-ISSN

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Počet stran výsledku

8

Strana od-do

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Název nakladatele

Canadian Acoustical Association

Místo vydání

Canada

Místo konání akce

Montreal

Datum konání akce

1. 1. 2019

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

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