scholarly journals Combined Effect of Superabsorbent Polymers and Cellulose Fibers on Functional Performance of Plasters

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3679
Author(s):  
Jan Fořt ◽  
Jiří Šál ◽  
Jaroslav Žák

Plaster has, from ancient times, been used as a decorative material. However, the advances in materials engineering such as thermal and moisture control provide new opportunities. Superabsorbent polymers (SAPs) have been found to possess passive moisture control that may find utilization in modern buildings. However, the main drawback is associated with a limited number of applicable SAPs due to mechanical strength loss. In this regard, concurrent utilization of cellulose fibers may provide additional benefits linked with the reinforcing of plaster structure and preservation of superior hygric properties. In this regard, this study investigates the combined effect of SAP and cellulose fibers on the material properties of cement-lime plaster in terms of its mechanic, thermal, and hygric properties. To access the capability of such modified plasters to control the interior moisture fluctuations, the moisture buffering value is determined. Obtained results show the effect of both applied admixtures on material performance, whilst the synergic effect was most obvious for humidity control accessed through the moisture buffer coefficient.

2016 ◽  
Vol 2 (2) ◽  
pp. 1
Author(s):  
Rosanne Walker ◽  
Sara Pavía

ResumenMejorar el rendimiento térmico de los edificios mediante la adaptación del aislamiento puede reducir la pérdida innecesaria de calor y energía minimizando el impacto ambiental. El aislamiento térmico interior es a menudo el elegido en los edificios históricos para preservar sus características. Sin embargo, el aislamiento interior puede aumentar la acumulación de humedad en paredes que socavan su durabilidad. Hay una falta de conocimiento sobre la eficacia de sólidos muros históricos y el impacto del aislamiento interno en su comportamiento higrotérmico. Este artículo investiga las propiedades térmicas e hídricas de siete opciones de aislamiento internos, incluyendo la pintura térmica, aerogel (AG), corcho-cal (CL), cal-cáñamo (HL), silicato de calcio bordo (CSB), tablero de fibra de madera (TFB) y placa de polisocianurato (PIR). Sus propiedades se comparan con un enlucido de cal tradicional. El PIR y el aerogel AG muestran extraordinarias propiedades térmicas que contribuyen a la comodidad y ahorro de energía, y la CL y HL son permeables al vapor y a la capilaridad. Estos tienen aproximadamente el doble de la masa térmica de los otros aislantes. Además, la CL tiene una buena inercia térmica (segunda difusividad más baja) y, a pesar de su contenido orgánico, una adsorción de baja a alta RH.AbstractImproving the thermal performance of buildings by retrofitting insulation can reduce unnecessary heat loss and building operational energy minimising environmental impact. Internal thermal insulation is often favoured for historic buildings to preserve their features. However, internal insulation may increase moisture accumulation in walls undermining their durability. There is a lack of knowledge on the performance of historic solid walls and the impact of internal insulation in their hygrothermal behaviour. This paper investigates the thermal and hygric properties of seven internal insulation options including thermal paint, aerogel (AG), cork lime (CL), hemp lime (HL), calcium silicate board (CSB), timber fibre board (TFB) and polyisocyanurate (PIR) board. Their properties are compared with a traditional lime plaster. The PIR and aerogel AG show outstanding thermal properties that contribute towards indoor thermal comfort and energy savings and the CL and HL are vapour permeable and capillary active. They have approximately double the thermal mass of the other insulations. In addition, the CL has a good thermal inertia (2nd lowest diffusivity) and, in spite of its organic content, a low adsorption at high RH.


PLoS ONE ◽  
2012 ◽  
Vol 7 (9) ◽  
pp. e45699 ◽  
Author(s):  
Carlos R. Bueno Júnior ◽  
Lucas C. Pantaleão ◽  
Vanessa A. Voltarelli ◽  
Luiz Henrique M. Bozi ◽  
Patricia Chakur Brum ◽  
...  

2021 ◽  
Vol 301 ◽  
pp. 124307
Author(s):  
P. Muñoz ◽  
V. Letelier ◽  
L. Muñoz ◽  
M.A. Bustamante ◽  
O. Gencel ◽  
...  

Author(s):  
John Michopoulos ◽  
Athanasios Iliopoulos ◽  
John Steuben ◽  
Andrew Birnbaum ◽  
Nicole Apetre ◽  
...  

The central goal of this chapter is to present an outline of the plan and current status of an effort to connect Additive Manufacturing (AM) process parameters with parameters describing the functional performance of produced parts. The term “functional performance” here represents primarily mechanical or thermal or electrochemical performance. The described effort represents an overview of the main research activities within a new multi-year grand-challenge project initiated at the US Naval Research Laboratory (US-NRL) in late 2016, in collaboration with groups from various academic institutions.


2020 ◽  
Vol 172 ◽  
pp. 11009
Author(s):  
Jan Fořt ◽  
Petr Hotěk ◽  
Jan Kočí ◽  
Robert Černý

The level of indoor humidity has to meet several criteria according to the preservation of a healthy indoor climate for building inhabitants. On top of that, the undesired moisture content is associated with a proliferation of various organisms which results in an adverse effect on the durability of building materials. Facing the impact of climate change and excessive energy consumption associated with building maintenance, the employment of passive moderation techniques takes place to avoid the usage of energy-demanding HVAC devices. The application of advanced materials such as superabsorbent polymers (SAPs), commonly used in diapers or other hygiene products, can bring a very effective solution for this issue overcoming. In this paper, the effect of 0.5; 0.1 and 1.5 wt.% dosages of SAPs incorporated into a cement-lime plaster are studied to evaluate the material performance in the sense of moisture moderation. First, the basic material properties, moisture transport and storage properties, thermal conductivity and specific heat capacity are determined to access the influence of SAP admixtures on the functional performance of studied plasters. Consequently, the experimentally accessed results are further employed for the computational modeling analysis which evaluates the capability of studied plasters for the moderation of moisture content in constructions.


Author(s):  
S. E. Keckler ◽  
D. M. Dabbs ◽  
N. Yao ◽  
I. A. Aksay

Cellular organic structures such as wood can be used as scaffolds for the synthesis of complex structures of organic/ceramic nanocomposites. The wood cell is a fiber-reinforced resin composite of cellulose fibers in a lignin matrix. A single cell wall, containing several layers of different fiber orientations and lignin content, is separated from its neighboring wall by the middle lamella, a lignin-rich region. In order to achieve total mineralization, deposition on and in the cell wall must be achieved. Geological fossilization of wood occurs as permineralization (filling the void spaces with mineral) and petrifaction (mineralizing the cell wall as the organic component decays) through infiltration of wood with inorganics after growth. Conversely, living plants can incorporate inorganics into their cells and in some cases into the cell walls during growth. In a recent study, we mimicked geological fossilization by infiltrating inorganic precursors into wood cells in order to enhance the properties of wood. In the current work, we use electron microscopy to examine the structure of silica formed in the cell walls after infiltration of tetraethoxysilane (TEOS).


2007 ◽  
Vol 177 (4S) ◽  
pp. 79-80
Author(s):  
Jose A. Karam ◽  
Yair Lotan ◽  
Raheela Ashfaq ◽  
Claus G. Roehrborn ◽  
Arthur I. Sagalowsky ◽  
...  

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