Romanian Academy of Science
Institute of Physical Chemistry “Ilie
Murgulescu”
Spl. Independentei 202, 060021
Bucharest,
M.Constantinescu1, L.Dumitrache2, S.Serban2, P.M.Pavel1,
A.Stoica1, M.Ghiurea2, M.Ladaniuc2 and M.Olteanu1.
1.ICF-AR “Ilie Murgulescu” 2. ICECHIM Bucuresti
Objectives and importance of energy storage in PCM
Nanocomposites preparation
1)Glauber(Na2SO410H2O)+5%Borax(Na2B4O7)+Ad
-Temperature domain: 15-30C
-Phase change temperature -31C.
-Microencapsulation in epoxi resin as a cross-linked structure
-Geometric form of the material is application dependant
2) an epoxi mixture of polyethylene glycol of different molecular
weights (1000, 1500, 2000) with Al powder).
3)-Eutectics of the binary and ternary systems :
--Acetamide+ sodium acetate trihidrate
-sodium tiosulfate(Na2S2O3.5H2O)+ sodium acetate
trihidrate
- Working temperature <60C
Energy storage aims to reduce the conventional energy consumtion with a direct impact
on CO2 emissions.
The advantages of phase change materials:
A constant temperature domain for the phase transformation, chosen for each application.
High storage density 70-100 kWh/m3
Directions of researches on heat storage in phase change materials :
Finding new materials with superior performances
Elimination of existent material disadvantages.
PCM +Ad melted and mixed with
epoxi resin
The PCM-epoxi nano-composite materials obtained as cross-linked three dimensional structures are attractive
for space heating and cooling of buildings able to reduce the space and costs for containerization.
CH3
Properties of nanocomposites substantially improved:
Mechanical properties :
strength, modulus and dimensional stability i.e. by using a nanocomposite PCM-epoxi increases the strength by 100%
Thermal stability
Thermal resistance, flame retardancy and reduced smoke emissions :Nanocomposites, with their superior thermal resistance, are also attractive for
applications as housings for electronics
Chemical resistance
The use of polymer-based nanocomposites are used as anticorrosion coatings on metals, and thin-film sensor.
Decreased permeability to gases, water and hydrocarbons
Polymer-matrix nanocomposites can also be used to package films, due to their superior barrier properties and low permeability
CH2
CH CH2 O
O
C
O CH2
CH3
CH CH2
O
+
Phase Change Materials
Glauber(Na2SO410H2O)+5%Borax
(Na2B4O7)+Al
Nanocomposites PEG
1000 ,1500 +Al
DSC for epoxi-PEG 1000 +Al
Demands for Phase
Change Material
PCM
Salt hydrates
Melting
temperature
C
Melting
heat
kJ/kg
PCM
Organic materials
KF.4H2O
18.5
231
Butilstearate
19
140
CaCl26 H2O
29.7
171
1-dodecanol
26
200
Na2SO4 .10H2O
32.4
254
Parafins
20-26
200
Na2HPO4.
12 H2O
35.0
281
45/55capric/lauric acid
21
143
Zn(NO3)2.
4 H2O
36.4
147
Propil palmitate
19
186
Ca(NO3)2. 4H2O
47.0
LiClO3.
3 H2O
46.5
253
58
165.5
Mn(NO3)2.
6 H2O
153
Melting
temperature
C
Polyethylenglycole
1000-2000
37-64
1-tetradecanol
38
Melting
heat
kJ/kg
83.2
218.4
Physico-chemical:
-Phase change temperature in the required
domain
-High latent heat of phase change and caloric
capacity
-High thermal conductivity
-Low undercooling
-Low volume changes
-Reversible phase transition
-Good physical and chemical stability
Kinetical :
205
-High nucleation and crystal grow velocity
Economical :
-low cost
-Reciclability
-Non-toxicity
Material characterization and testing
Glauber+borax+amonium sulphate
decahydrate +Al nano
Polyethylene Glycol- M2000
Hardening reaction of epoxi resin
with PCM
DSC for PEG 1500
Innovative applications
Phase change materials have been employed in:
Thermal energy storage
Conditioning of buildings
Waste heat recovery
Off peak power utilization
Heat pump systems
Space applications
Laptop computer cooling
Cool suits
Telecom shelters
melted PCM in the epoxi matrix
SEM micrographs for polyethylene glycol(PEG) 2000
SEM micrographs for Glauber –epoxi Al nano
Solar houses Kirally
Passive and active
cooling Rubiterm
Blood motion
Rubiterm
CONCLUSIONS
1.The nanocomposite materials for buildings were obtained by using melted (PCM +additives) 70 wt%, incorporated in an epoxidic resin 30 wt%. For all Epoxi-PCM materials was used Ropoxid 501 (Policolor), with
a hardener threeethylentetramine (TETA) or I 3361 (Policolor). The composition of the inorganic PCM was: (Glauber salt)70wt %, additives (borax 10wt%, NH4HCO3, (NH4)2SO4, or CaCO3 20wt% and Al powder
0.1wt% for enhancing the thermal conductivity of the material, whereas the organic PCM ( polyethyleneglycoles 1000, 1500 and 2000) were also 70wt% and 0.1 wt%Al powder. The system hardened at the ambient
temperature.
2.The materials present good mechanical, thermal and chemical properties suitable for building materials.
3.They can be used for different applications in active or pasive systems, depending on their melting temperature.The geometry used depends also on their melting temperature and on the chosen application.
4. Energy storage in building materials will reduce the conventional energy consumptions, will increase the living comfort, decreasing the CO2 emissions.