Banca de DEFESA: JOSE AIRTON CUNHA COSTA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : JOSE AIRTON CUNHA COSTA
DATA : 21/03/2019
HORA: 09:00
LOCAL: Sala de aulas do PPGCEM
TÍTULO:

Formulation of phase change materials by the addition of vermiculite, diatomite and paraffin and application in cemetning mortars.

PALAVRAS-CHAVES:

Phase change material, vermiculite, diatomite, paraffin, mortars.

PÁGINAS: 110
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
SUBÁREA: Materiais Não-Metálicos
ESPECIALIDADE: Cerâmicos
RESUMO:

In order to ensure the thermal comfort of its users, residential and commercial buildings consume a large amount of energy to heat and cool the indoor environments and, consequently, air conditioners emit significant amounts of greenhouse gases in urban agglomerations. Concerns in the current century to reduce energy consumption and emission of gases, therefore, lead to advances in the use of materials capable of storing energy in the phase transition process, with special dedication to PCMs (Phase Change Materials). In this study, a material with phase change, PCM, with potential for improving thermal performance in cement mortars, consisting of two solid and liquid paraffins (naphthenic oil) and two minerals as a support matrix (calcined diatomite and vermiculite expanded). First, characterizations by DSC and FT-IR were performed to determine the best ratio between paraffins for application in residential and commercial buildings. The starting minerals were characterized by TG, DTA, FRX, MEV, BET and FT-IR. PCM samples (paraffin + vermiculite) and PCM (1 + 2) (paraffin + diatomite + vermiculite) were prepared from the selected paraffin mixture and the minerals, and then named PCM1 (paraffin + diatomite), PCM2 characterized by MEV, FT-IR, BET. Cement mortars were prepared in volume ratio: 1: 4 cement: sand (control trace), 1: 4: 1 cement: sand: diatomite, cement 1: 4: 1: sand: vermiculite and 1: 4: 1 cement: sand: PCMs, and had their thermal properties measured. Finally, the thermal properties of PCM(1 + 2) were evaluated, varying to the sand volume, in the proportions of 0%, 25%, 50%, 75% and 100%. The DSC results of the paraffin blends pointed to the composition at 20% liquid paraffin as being ideal because it has adequate solid-liquid temperature and latent heat suitable for buildings. All PCMs had lower thermal conductivities than the control (1.47W / m.K), with PCM (1 + 2) being the lowest of them (0.82W / m.K). The PCM (1 + 2) also presented better diffusivity, volumetric heat capacity and thermal resistance. The simultaneous addition of vermiculite and diatomite to the composition of PCMs results in the improvement of their thermal properties, maintaining their fundamental characteristics as chemical and structural stability.

MEMBROS DA BANCA:
Externa à Instituição - ANA CECILIA VIEIRA DA NOBREGA - UFPE
Presidente - 1298936 - ANTONIO EDUARDO MARTINELLI
Externo ao Programa - 1235107 - GEORGE SANTOS MARINHO
Interno - 1350249 - RUBENS MARIBONDO DO NASCIMENTO
Externo à Instituição - ULISSES TARGINO BEZERRA - IFPB