پایگاه تخصصی نساجی و پوشاک
گیل تکس
به کانال تلگرام ما بپیوندید:
www.t.me/taroopod
================
ادامه...
-SiO2
on morphology, thermal energy storage, thermal stability, and
combustion properties of electrospun lauric acid/PET ultrafine
composite 
fibers as form-stable phase change materials Yibing
, 
, Jiulong, , Weidong
The ultrafine composite fibers consisting of lauric acid (LA), polyethylene terephthalate (PET), and silica nanoparticles (nano-SiO2)
were prepared through the materials processing technique of
electrospinning as an innovative type of form-stable phase change
materials (PCMs). The effects of nano-SiO2 on morphology, thermal energy storage, thermal stability, and combustion properties of electrospun LA/PET/SiO2 composite fibers were studied. SEM images revealed that the LA/PET/SiO2 composite fibers with nano-SiO2 possessed desired morphologies with reduced average fiber diameters as compared to the LA/PET fibers without nano-SiO2. DSC measurements indicated that the amount of nano-SiO2 in the fibers had an influence on the crystallization of LA, and played an important role on the heat enthalpies of the composite fibers; while it had no appreciable effect on the phase change temperatures. TGA results suggested that the incorporation of nano-SiO2
increased the onset thermal degradation temperature, maximum weight
loss temperature, and charred residue at 700 °C of the composite fibers, indicating the improved thermal stability of the fibers. MCC tests showed that the heat resistance effect and/or barrier property generated by nano-SiO2
resulted in an increase of initial combustion temperature and a
decrease of the heat release rate for the electrospun ultrafine
composite fibers.
Keywords: Form-stable phase change materials; Electrospinning; LA/PET composite fibers; Nano-SiO2; Morphology; Thermal energy storage
fiber [13], [16] and [17], and β-Aluminum nitride [18]
have been incorporated into PCMs. Another problem is related to the
encapsulation of PCMs: PCMs have to be placed in specially designed
devices/containers during applications. Such a situation not only
raises the concern of thermal resistivity between the
devices/containers and PCMs, but also increases the operational costs.
To overcome this problem, polymer-matrix PCMs with phase change
material (e.g., fatty acids) supported by polymeric materials (e.g., polymethyl methacrylate [9] and [10] and polyethylene oxide [11] and [12])
have been explored; these PCMs are termed as “form-stable PCMs”, and
they possess the advantageous properties such as no need for additional
encapsulation, cost-effectiveness, stable shape, and readiness for
applications with tunable dimension.The materials processing technique of electrospinning is a straightforward and versatile method for producing ultrafine fibers with diameters ranging from tens of nanometers to microns [19], [20] and [21]. The applications of electrospun ultrafine fibers include, but not limited to, composites, filtration/separation, protective clothing, biomedical applications (e.g., wound dressing, tissue engineering, and drug delivery), electronic applications (e.g., sensors and transistors), and energy applications (e.g., solar cells) [21] and [22]. Recently, the electrospinning technique has been utilized to develop an innovative type of form-stable PCMs (i.e., ultrafine fibers of polymer-matrix PCMs). McCann and coworkers [23] first reported the preparation of phase change ultrafine fibers with cores being long-chain hydrocarbons and sheaths being TiO2-polyvinylpyrrolidone, and the fibers were prepared through coaxial electrospinning. Chen and coworkers [24], [25] and [26] reported that the ultrafine fibers
of polyethylene glycol/cellulose acetate (PEG/CA) composites could be
prepared through electrospinning the mixture solutions of PEG and CA;
in their composite fibers, PEG acted as the phase change material while CA acted as the supporting material. Their results indicated that the composite fibers had high thermal stability due to the supporting and/or shielding effect of the CA matrix [24].
Additionally, they studied the effects of molecular weight of PEG on
morphological structures, thermal characteristics, and tensile
properties of the electrospun PEG/CA composite fibers [25]. To further improve the thermal stability as well as the water-resistivity of their electrospun PEG/CA composite fibers, the CA macromolecules on the surface of fibers
were crosslinked using toluene-2,4-diisocyanate as the crosslinking
agent; and the results showed that the crosslinking led to the
improvement on thermal stability, but also resulted in the decrease of
heat enthalpy [26].
It
is noteworthy that an important application of PCMs is for making
construction materials, while the above-described PCMs cannot be
directly utilized due to high flammability and/or low thermal stability
of both the phase change materials and the supporting materials. This
study aimed at the development and characterization/evaluation of
form-stable PCMs with improved thermal stability as well as reduced
flammability. Long-chain fatty acid of lauric acid (LA) was selected as
the phase change material, and polyethylene terephthalate (PET) was
selected as the supporting material; the LA/PET ultrafine composite fibers
were fabricated by the technique of electrospinning. To improve the
thermal stability and combustion resistance of the electrospun
ultrafine fibers, the silica nanoparticles (nano-SiO2)
with large surface area, high strength, excellent heat stability, good
chemical resistance, and high thermal conductivity were incorporated
into the fibers. The nano-SiO2 has been widely used for preparation of composite fibers because they can provide the fibers with improved properties including higher hydrophilicity, toughness, and permeability [27], [28] and [29]. The effects of different amounts of nano-SiO2 on morphology, thermal energy storage, thermal stability, and combustion properties of electrospun LA/PET/SiO2 composite fibers were investigated. The results suggested that the LA/PET/SiO2 composite fibers possessed desired morphological and thermal properties, and they could be used as an innovative type of form-stable PCMs.
The pellets of PET (Mw = 18,000–25,000) were obtained from the Shanghai Plastics Co. (Shanghai, China). The powder of LA (CH3(CH2)10COOH) and the nanoparticles of SiO2 (with the size of 
20 nm)
were supplied by the Shanghai Chemical Regents Co. (Shanghai, China).
Dichloromethane (DCM) and trifluoroacetic acid (TFA) were purchased
from the Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). All of
the chemicals were used without further purifications.
To
prepare the spin dopes for electrospinning, 15 wt.% PET pellets were
first dissolved in mixture solvents with the volume ratio of DCM/TFA
being 2/1, LA powders were then dissolved in the solutions with the
LA/PET mass ratio being set at 70/100. Subsequently, varied mass
fractions (i.e., 1%, 2%, 3%, and 4%) of SiO2
nanoparticles were added into the LA/PET solutions followed by magnetic
stirring for 2 h to achieve the uniform dispersion. The motivation for
the addition of SiO2 nanoparticles was to improve the thermal stability as well as the combustion resistance of electrospun ultrafine fibers. Prior to the preparation of spin dopes, the SiO2 nanoparticles were desiccated under vacuum at 80 °C.
fibersA
spin dope was filled in a 30 ml plastic syringe having a blunt-end
stainless-steel needle with the inside diameter of 0.30 mm. The
electrospinning setup included a high voltage power supply, purchased
from the Dongwen Co. (Tianjing, China), and a nanofiber collector of
electrically grounded aluminum foil that covered a laboratory-produced
roller. The rotating speed of the roller was set at 100 rpm. The
collector was placed at 18 cm below the tip of needle. During
electrospinning, a positive high voltage of 16 kV was applied to the
needle; and the solution feed rate of 3.0 ml/h was maintained using a
syringe pump purchased from the Medical Instrument Co. (Hangzhou,
China). The electrospun ultrafine composite fibers were collected as overlaid fibrous mats with detailed sample codes and compositions shown in Table 1.
fibers. | Sample codes | Compositionsa |
|---|---|
| PET1 | WLA:WPET = 70:100 |
| PET2 | WLA:WPET = 70:100, WS:(WPET + WLA + WS) = 1 wt.% |
| PET3 | WLA:WPET = 70:100, WS:(WPET + WLA + WS) = 2 wt.% |
| PET4 | WLA:WPET = 70:100, WS:(WPET + WLA + WS) = 3 wt.% |
| PET5 | WLA:WPET = 70:100, WS:(WPET + WLA + WS) = 4 wt.% |
A Quanta-200 scanning electron microscope (SEM) was employed to examine morphologies of the ultrafine fibers; prior to SEM examination, all specimens were sputter-coated with gold to avoid charge accumulations.
The studies of differential scanning calorimetry (DSC) were carried out in dry nitrogen using the Perkin–Elmer Diamond DSC thermal analyzer; the flow rate of nitrogen was set at 20 ml/min, and the DSC curves were recorded from 20 to 100 °C with the scanning rate being set at 10 °C/min. The precisions of measurements for calorimeter and temperature during DSC experiments were ±2.0% and ±2.0 °C, respectively; Indium was used as the reference for calibration of temperature. Approximately 10 mg of sample was used for the DSC studies to avoid the possible thermal lag. The enthalpy of melting (ΔHm) and the enthalpy of crystallization (ΔHc) were calculated based upon the areas under the solid–liquid phase change peaks of LA using the thermal analysis software affiliated with the equipment.
TGA experiments were conducted
by using a TGA-Q5000 thermo-analyzer instrument; the heating rate was
set at 10 °C/min, and the TGA curves were recorded from 25 to 700 °C
under 25 ml/min flow of nitrogen. The amounts of samples for the TGA
analyses were 10 mg. The precisions of measurements for temperature and mass during TGA experiments were ±2.0 °C and ±2.0%, respectively.
Combustion properties were evaluated by using the Govmark microscale combustion calorimetry (MCC), which measured the consumption of oxygen during experiment. The signals from MCC were recorded and analyzed by the affiliated computer system. The samples were first pyrolyzed with a linear heating rate of 1 °C/s in the furnace of MCC. The decomposed components were carried away by an inert gas; subsequently, they were mixed with oxygen followed by being combusted at 900 °C. The amounts of samples for the MCC tests were approximately 4–6 mg.
PET
has been widely used for many applications due to excellent mechanical
properties as well as thermal and chemical resistances. The melting
temperature of PET is higher than that of LA; thus, PET can act as the
supporting material in the form-stable phase change ultrafine composite
fibers.
In other words, PET can prevent the leakage of the molten LA when the
temperature is higher than the melting point of LA. The representative
morphologies of electrospun PET fibers, LA/PET fibers, and LA/PET/SiO2 fibers with different amounts (2 wt.% and 4 wt.%) of nano-SiO2 are shown in Fig. 1. The image of Fig. 1a indicates that the neat PET fibers were quite uniform in diameters, and the fibers were cylindrical with smooth surfaces. However, the LA/PET fibers were less uniform with wrinkled surfaces, and the conglutination of some fibers could be occasionally observed; this suggested that there might be hydrogen bonding interactions among the carboxyl (COOH) groups in LA and the carbonyl (C
O)
groups in PET. The above results were consistent with the previously
reported studies on the fatty acid eutectic/polymethyl methacrylate
composites [10], polyethylene glycol/cellulose acetate (PEG/CA) blends [24], [25] and [26], PEG/acrylic polymer blends [30], PEG/ poly(methacrylic acid) blends [31], styrene maleic anhydride copolymer/fatty acid composites [32], and melamine–formaldehyde prepolymers/polyvinyl alcohol composites [33].
| Full-size image (135K) |
Representative SEM images of electrospun ultrafine fibers: (a) neat PET fibers, (b) PET1, (c) PET3, and (d) PET5.
As shown in Fig. 1c and d, morphologies and average diameters of the electrospun LA/PET/SiO2 composite fibers were affected by the addition of nano-SiO2. Compared with the LA/PET fibers (Fig. 1b), the LA/PET/SiO2 composite fibers appeared to have the smooth surface, and the degree of fiber adhesion was reduced; additionally, the average diameter of the LA/PET/SiO2 composite fibers was considerably smaller than that of the LA/PET fibers, and it was evident that the average diameter decreased with the increase of nano-SiO2 amount. Such a result might be attributed to the increased conductivity of the spin dope upon the addition of nano-SiO2. It is noteworthy that the SiO2 nanoparticles were uniformly distributed in the spin dopes as well as in the fibers, and this was due to the interaction of hydrogen bonding (1) between carboxyl groups in LA and silanol (SiOH) groups on the surface of
nano-SiO2,
(2) between carboxyl groups in LA and carbonyl groups in PET, and (3)
between carbonyl groups in PET and silanol groups on the surface of nano-SiO2 [27], [28] and [34]. The hydrogen bonding interactions among nano-SiO2, LA, and PET were schematically shown in Fig. 2. Additionally, the uniform distribution of nano-SiO2 in spin dopes also resulted in the reduced fiber diameters, because the repulsive force generated by nano-SiO2
could mitigate the chain entanglement of PET macromolecules. Similar
results were also reported in previous research on the electrospun
PAN/SiO2 composite fibers [27] and [28].
| Full-size image (25K) |
Schematic representation showing hydrogen bonding interactions among nano-SiO2, LA, and PET in the ultrafine composite fibers.
DSC curves acquired from heating and cooling of electrospun LA/PET and LA/PET/SiO2 fibers are shown in [Fig. 3] and [Fig. 4], respectively; the data of melting temperature (Tm), enthalpy of melting (ΔHm), crystallization temperature (Tc), and enthalpy of crystallization (ΔHc) are listed in Table 2. The phase transition temperatures were recorded as the maximum values of the DSC curves. Compared to those of LA/PET fibers, the values of ΔHm and ΔHc for the LA/PET/SiO2 fibers first increased and then decreased with the increase of nano-SiO2 amount. The increases of ΔHm and ΔHc values were probably due to the facilitation of LA crystallization in the composite fibers having low amounts of nano-SiO2, because the SiO2
nanoparticles with high thermal conductivity could act as the
nucleation agent and effectively promote the heterogeneous nucleation
of LA. Nonetheless, the values of ΔHm and ΔHc decreased with further increase of nano-SiO2 amount. This might be resulted from the retardation of crystallization for LA in the composite fibers; i.e., the crystallization was hindered by the quench effect during electrospinning and the dilution effect of PET in the composite fibers.
Since the evaporation of solvent(s) during the electrospinning process
occurs in the time scale of milliseconds, the LA molecules may not have
enough time to form well-defined structures in the composite fibers [25], [35] and [36].
It was also believed that the hydrogen bonding interactions among
carboxyl groups in LA, carbonyl groups in PET, and silanol (SiOH) groups on
nano-SiO2 led to the formation of three-dimensional networks in ultrafine fibers; additionally, the nano-SiO2
with large surface-to-mass ratio also had strong effect on adsorption
of lauric acid. The combination of hydrogen bonding interactions,
three-dimensional networks, and strong adsorption effect substantially
limited the movement of LA molecules during the melting and
crystallization processes, leading to the reduced crystallinity of LA
in the composite fibers and the decreased values of enthalpies. It was intriguing that the Tm and Tc values of the LA/PET/SiO2 composite fibers had no distinguishable variations as compared to those of LA/PET fibers without nano-SiO2. The results in Fig. 4 and Table 2 also indicated that the positions of phase change peaks and the heat enthalpies of composite fibers
had reasonably good consistence between the cooling and heating
processes. This suggested that the thermal cycling had no appreciable
influences on the properties of thermal energy storage for electrospun
LA/PET/SiO2 ultrafine composite fibers.
| Full-size image (36K) |
DSC curves of electrospun LA/PET and LA/PET/SiO2 ultrafine composite fibers during heating process.
| Full-size image (34K) |
DSC curves of electrospun LA/PET and LA/PET/SiO2 ultrafine composite fibers during cooling process.
fibers. | Sample codes | Tm (°C) | ΔHm (kJ/kg) | Tc (°C) | ΔHc (kJ/kg) |
|---|---|---|---|---|
| PET1 | 44.6 | 57.0 | 38.0 | 32.1 |
| PET2 | 46.0 | 62.9 | 38.8 | 41.5 |
| PET3 | 45.1 | 58.4 | 38.0 | 37.9 |
| PET4 | 45.0 | 56.3 | 39.1 | 33.8 |
| PET5 | 44.6 | 55.8 | 38.6 | 29.9 |
The thermal stabilities of ultrafine composite fibers with and without SiO2
were evaluated by thermogravimetric analysis (TGA). The TGA and
differential thermogravimetric analysis (DTGA) curves of LA/PET and
LA/PET/SiO2 fibers are shown in [Fig. 5] and [Fig. 6], respectively. The 5% weight loss temperature (T−5wt.%), the maximum decomposition temperatures (Tmax1 and Tmax2), and the charred residue at 700 °C are listed in Table 3. As shown in Fig. 5 and Table 3, the values of T−5wt.% for the LA/PET/SiO2 composite fibers were 7–9 °C higher than that for the LA/PET fibers; this was attributed to the excellent heat stability and heat resistance of nano-SiO2, suggesting that the incorporation of nano-SiO2 improved the thermal stability of LA/PET/SiO2 ultrafine composite fibers.
fibers. | Sample codes | T−5wt.% (°C) | Tmax1 (°C) | Tmax2 (°C) | Charred residue (700 °C) |
|---|---|---|---|---|
| PET1 | 119.0 | 145.4 | 419.7 | 8.37 |
| PET2 | 128.2 | 156.5 | 421.8 | 8.38 |
| PET3 | 126.6 | 154.3 | 421.2 | 10.8 |
| PET4 | 126.9 | 154.5 | 426.1 | 10.6 |
| PET5 | 128.2 | 156.7 | 427.4 | 10.9 |
Additionally, the TGA and DTGA curves also indicated that there were two steps of degradation for the composite fibers. The first step was the weight loss occurring at 120–180 °C, and the maximum decomposition temperature (Tmax1) was at 145–157 °C; such a weight loss was corresponding to the degradation of LA in composite fibers, as indicated in Fig. 6a. The second step was the weight loss occurring at 340–480 °C, and the maximum decomposition temperature (Tmax2) was at 419–427 °C, as indicated in Fig. 6b; such a weight loss was attributed to the decomposition of PET in composite fibers. As shown in Table 3 and Fig. 6a & b, the values of Tmax1 and Tmax2 increased with the increase of nano-SiO2 amount in the composite fibers: the Tmax1 and Tmax2
values were 145.4 °C and 419.7 °C for PET1, 156.5 °C and 421.8 °C for
PET2, 154.3 °C and 421.2 °C for PET3, 154.5 °C and 426.1 °C for PET4,
and 156.7 °C and 427.4 °C for PET5. Therefore, the increases of Tmax1 was approximately 9–11 °C, while the increase of Tmax2 was about 2–8 °C. Furthermore, the values of charred residue at 700 °C also increased slightly with the increase of the nano-SiO2 amount. Theses increases indicated that the thermal stability of the electrospun LA/PET/SiO2 ultrafine composite fibers was improved, and the improvement was attributed to the SiO2 nanoparticles. It is known that SiO2 is an inorganic fire-retardant material, and the SiO2 nanoparticles on the surface of the electrospun ultrafine fibers could create a passivation layer during thermal degradation process; additionally, SiO2
could also act as an insulator and/or mass transport barrier to the
volatile byproducts generated during the thermal decomposition, leading
to the improvement on thermal stability of the electrospun ultrafine
composite fibers.
The
microscale combustion calorimetry (MCC) is one of the most effective
bench-scale methods for investigating the combustion properties of
polymeric materials. The peak of heat release rate (PHRR) is one of the
most important parameters to evaluate fire safety [37] and [38]. The combustion properties of LA/PET/SiO2 composite fibers with varied amounts of nano-SiO2 were characterized by MCC, and the results were compared to those of LA/PET fibers without SiO2. The HRR curves of the LA/PET fibers as well as LA/PET/SiO2 composite fibers with 2 wt.% and 4 wt.% of SiO2 are in Fig. 7. It was evident that the initial combustion temperature of LA/PET/SiO2 composite fibers shifted to high temperature region in comparison with that of LA/PET fibers; however, the initial HRR for the LA/PET/SiO2 composite fibers was lower than that of the LA/PET fibers at the beginning of combustion. The reasons might be attributed to the heat resistance effect and/or barrier property of nano-SiO2. It is noteworthy that there were two combustion regions for all of the ultrafine fibers.
The first combustion region occurred roughly at 100–250 °C, which was
corresponded to the heat release of lauric acid. The incorporation of nano-SiO2 slightly increased the PHRR values of LA/PET/SiO2 composite fibers, which might be caused by the thermal reaction among silanol (SiOH) groups on the surface of
nano-SiO2.
The second combustion region occurred in the range of 350–500 °C, which
might be associated with the thermal degradation of PET. The PHRR
values of LA/PET/SiO2 composite fibers slight decreased with the increase of nano-SiO2 amount, which was due to the fire-retardant and/or heat resistance effects of nano-SiO2. In addition, the nano-SiO2 could generate a physical protective layer on the surface of composite fibers during combustion. Thus, the incorporation of nano-SiO2 could lead to the increase of initial combustion temperature and the decrease of HRR values (i.e., the improvement on combustion performance).
| Full-size image (35K) |
Heat release rate (HRR) curves of LA/PET and LA/PET/SiO2 ultrafine composite fibers.
An innovative form-stable phase change materials of LA/PET/SiO2 ultrafine composite fibers was prepared by the technique of electrospinning. The effects of SiO2
nanoparticles on morphological structure, thermal energy storage,
thermal stability, and combustion properties of the ultrafine composite
fibers were investigated by SEM, DSC, TGA, and MCC. SEM images revealed that the LA/PET/SiO2 composite fibers with nano-SiO2 possessed desired morphologies with reduced average fiber diameters as compared to the LA/PET fibers without nano-SiO2;
this was probably due to the increased conductivity of the spin dopes
and the strong hydrogen bonding among the components in the fibers. DSC measurements indicated that the amount of nano-SiO2 in the fibers had an influence on the crystallization of LA, and played an important role on the heat enthalpies of the composite fibers; while it had no appreciable effect on the phase change temperatures. TGA results suggested that the incorporation of nano-SiO2
increased the onset thermal degradation temperature, maximum weight
loss temperature, and charred residue at 700 °C of the composite fibers, indicating the improved thermal stability of the ultrafine composite fibers. MCC tests showed that the heat resistance effect and/or barrier property generated by nano-SiO2
resulted in an increase of initial combustion temperature and a
decrease of the heat release rate for the electrospun ultrafine
composite fibers.
This
research was financially supported by the National Natural Science
Foundation of China (No. 51006046), the Natural Science Foundation of
Jiangsu Province (No. BK2010140), the Research Fund for the Doctoral
Program of Higher Education of China (No. 200802951011 and No.
20090093110004), the Open Project Program of State Key Laboratory of
Fire Science at University of Science and Technology of China (No.
HZ2009-KF06), the Fundamental Research Funds for the Central
Universities (No. JUSRP20903), the Open Project Program of Key
Laboratory of Green Processing and Functional Textile of New Textile
Materials at Wuhan Textile University (No. GTKL2009004), the
Undergraduate Innovation and Training Program of Jiangnan University
(No. 1009160), and the Open Project Program of State Key Laboratory for
Modification of Chemical Fibers and Polymer Materials at Donghua University (No. LK0901).
[1] S.M. Hasnain, Review on sustainable thermal energy storage technologies, part I: heat storage materials and techniques, Energy Convers Manage 39 (1998), pp. 1127–1138. Article | 
PDF (191 K)
| View Record in Scopus | Cited By in Scopus (168)
[2]
V. Pandiyarajan, M. Chinna Pandian, E. Malan, R. Velraj and R.V.
Seeniraj, Experimental investigation on heat recovery from diesel
engine exhaust using finned shell and tube heat exchanger and thermal
storage system, Appl Energy 88 (2011), pp. 77–87. Article | PDF (1569 K)
| View Record in Scopus | Cited By in Scopus (0)
[3]
B. Zalba, J.M. Marin, L.F. Cabeza and H. Mehling, Review on thermal
energy storage with phase change: materials, heat transfer analysis and
applications, Appl Therm Eng 23 (2003), pp. 251–283. Article | PDF (340 K)
| View Record in Scopus | Cited By in Scopus (386)
[4]
M. Medrano, M.O. Yilmaz, M. Nogués, I. Martorell, J. Roca and L.F.
Cabeza, Experimental evaluation of commercial heat exchangers for use
as PCM thermal storage systems, Appl Energy 86 (2009), pp. 2047–2055. Article | PDF (668 K)
| View Record in Scopus | Cited By in Scopus (6)
[5] M.M. Farid, A.M. Khudhair, S.A. Razack and S. Al-Hallaj, A review on phase change energy storage: materials and applications, Energy Convers Manage 45 (2004), pp. 1597–1615. Article | PDF (568 K)
| View Record in Scopus | Cited By in Scopus (216)
[6] H. EI Qarnia, Numerical analysis of a coupled solar collector latent heat storage unit using various phase change materials for heating the water, Energy Convers Manage 50 (2009), pp. 247–254.
[7]
G.B. Zhou, Y.P. Zhang, Q.L. Zhang, K.P. Lin and H.F. Di, Performance of
a hybrid heating system with thermal storage using shape-stabilized
phase-change material plates, Appl Energy 84 (2007), pp. 1068–1077. Article | PDF (267 K)
| View Record in Scopus | Cited By in Scopus (5)
[8] M. Rady, Thermal performance of packed bed thermal energy storage units using multiple granular phase change composites, Appl Energy 86 (2009), pp. 2704–2720. Article | PDF (2127 K)
| View Record in Scopus | Cited By in Scopus (3)
[9]
C. Alkan and A. Sari, Fatty acid/poly(methyl methacrylate) (PMMA)
blends as form-stable phase change materials for latent heat thermal
energy storage, Sol Energy 82 (2008), pp. 118–124. Article | PDF (451 K)
| View Record in Scopus | Cited By in Scopus (29)
[10]
L.J. Wang and D. Meng, Fatty acid eutectic/polymethyl methacrylate
composite as form-stable phase change material for thermal energy
storage, Appl Energy 87 (2010), pp. 2660–2665. Article | PDF (567 K)
| View Record in Scopus | Cited By in Scopus (1)
[11]
K. Pielichowska, S. Głowinkowski, J. Lekki, D. Binias, K. Pielichowski
and J. Jenczyk, PEO/fatty acid blends for thermal energy storage
materials. Structural/morphological features and hydrogen interactions,
European Polym J 44 (2008), pp. 3344–3360. Article | PDF (2088 K)
| View Record in Scopus | Cited By in Scopus (5)
[12] K. Pielichowski and K. Flejtuch, Recent developments in polymeric phase change materials for energy storage: poly(ethylene oxide)/stearic acid blends, Polym Adv Technol 16 (2005), pp. 127–132. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (12)
[13] A. Karaipekli, A. Sarı and K. Kaygusuz, Thermal conductivity improvement of stearic acid using expanded graphite and carbon 
fiber
for energy storage applications, Renew Energy 32 (2007), pp. 2201–2210. Article | PDF (349 K)
| View Record in Scopus | Cited By in Scopus (29)
[14]
A. Sarı and A. Karaipekli, Preparation, thermal properties and thermal
reliability of palmitic acid/expanded graphite composite as form-stable
PCM for thermal energy storage, Sol Energy Mater Sol Cells 93 (2009), pp. 571–576. Article | PDF (606 K)
| View Record in Scopus | Cited By in Scopus (14)
[15]
W.L. Wang, X.X. Yang, Y.T. Fang, J. Ding and J.Y. Yan, Preparation and
thermal properties of polyethylene glycol/expanded graphite blends for
energy storage, Appl Energy 86 (2009), pp. 1479–1483. Article | PDF (396 K)
| View Record in Scopus | Cited By in Scopus (11)
[16] J. Fukai, M. Kanou, Y. Kodama and O. Miyatake, Thermal conductivity enhancement of energy storage media using carbon fibers, Energy Convers Manage 41 (2000), pp. 1543–1556. Article | PDF (378 K)
| View Record in Scopus | Cited By in Scopus (67)
[17]
F. Frusteri, V. Leonardi, S. Vasta and G. Restuccia, Thermal
conductivity measurement of a PCM based storage system containing
carbon fibers, Appl Therm Eng 25 (2005), pp. 1623–1633. Article | PDF (396 K)
| View Record in Scopus | Cited By in Scopus (30)
[18]
W.L. Wang, X.X. Yang, Y.T. Fang, J. Ding and J.Y. Yan, Enhanced thermal
conductivity and thermal performance of form-stable composite phase
change materials by using β-Aluminum nitride, Appl Energy 86 (2009), pp. 1196–1200. Article | PDF (400 K)
| View Record in Scopus | Cited By in Scopus (17)
[19] D.H. Reneker and I. Chun, Nanometre diameter fibres of polymer, produced by electrospinning, Nanotechnology 7 (1996), pp. 216–223. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (1159)
[20] D. Li and Y.N. Xia, Electrospinning of nanofibers: reinventing the wheel?, Adv Mater 16 (2004), pp. 1151–1170. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (1106)
[21]
Z.M. Huang, Y.Z. Zhang, M. Kotaki and S. Ramakrishna, A review on
polymer nanofibers by electrospinning and their applications in
nanocomposites, Compos Sci Technol 63 (2003), pp. 2223–2253. Article | PDF (1264 K)
| View Record in Scopus | Cited By in Scopus (1212)
[22] S. Ramakrishna, K. Fujihara, W.E. Teo, T. Yong, Z.W. Ma and R. Ramaseshan, Electrospun nanofibers: solving global issues, Mater Today 9 (2006), pp. 40–50. Article | PDF (685 K)
| View Record in Scopus | Cited By in Scopus (129)
[23]
J.T. McCann, M. Marquez and Y. Xia, Melt coaxial electrospinning: a
versatile method for the encapsulation of solid materials and
fabrication of phase change nanofibers, Nano Lett 6 (2006), pp. 2868–2872. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (47)
[24] C.Z. Chen, L.G. Wang and Y. Huang, Electrospinning of thermo-regulating ultrafine fibers based on polyethylene glycol/cellulose acetate composite, Polymer 48 (2007), pp. 5202–5207. Article | PDF (552 K)
| View Record in Scopus | Cited By in Scopus (24)
[25] C.Z. Chen, L.G. Wang and Y. Huang, Role of Mn of PEG in the morphology and properties of electrospun PEG/CA composite fibers for thermal energy storage, AIChE J 55 (2009), pp. 820–827. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (1)
[26] C.Z. Chen, L.G. Wang and Y. Huang, Crosslinking of the electrospun polyethylene glycol/cellulose acetate composite fibers as shape-stabilized phase change materials, Mater Lett 63 (2009), pp. 569–571. Article | PDF (515 K)
| View Record in Scopus | Cited By in Scopus (4)
[27]
H.R. Jung, D.H. Ju, W.J. Lee, X.W. Zhang and R. Kotek, Electrospun
hydrophilic fumed silica/polyacrylonitrile nanofiber-based composite
electrolyte membranes, Electrochim Acta 54 (2009), pp. 3630–3637. Article | PDF (723 K)
| View Record in Scopus | Cited By in Scopus (6)
[28] L.W. Ji and X.W. Zhang, Ultrafine polyacrylonitrile/silica composite fibers via electrospinning, Mater Lett 62 (2008), pp. 2161–2164. Article | PDF (874 K)
[29] L.W. Ji, Z. Lin, A.J. Medrew and X.W. Zhang, Porous carbon nanofibers from electrospun polyacrylonitrile/SiO2 composites as an energy storage material, Carbon 47 (2009), pp. 3346–3354. Article | PDF (889 K)
| View Record in Scopus | Cited By in Scopus (4)
[30] C. Alkan, A. Sari and O. Uzun, Poly(ethylene glycol)/acrylic polymer blends for latent heat thermal energy storage, AICHE J 52 (2006), pp. 3310–3314. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (23)
[31] H.T. Oyama, D.J. Hemker and C.W. Frank, Effect of the degree of ionization of poly(methacrylic acid) on the complex formed with pyrene end-labeled poly(ethylene glycol), Macromolecules 22 (1989), pp. 1255–1260. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (30)
[32]
A. Sari, C. Alkan, A. Karaipekli and A. Onal, Preparation,
characterization and thermal properties of styrene maleic anhydride
copolymer (SMA)/fatty acid composites as form stable phase change
materials, Energy Convers Manage 49 (2008), pp. 373–380. Article | PDF (945 K)
| View Record in Scopus | Cited By in Scopus (22)
[33]
H.Z. Zhang and X.D. Wang, Fabrication and performances of
microencapsulated phase change materials based on n-octadecane core and
resorcinol-modified melamine-formaldehyde shell, Colloid Surf A: Physicochem Eng Aspects 332 (2009), pp. 129–138. Article | PDF (1894 K)
| View Record in Scopus | Cited By in Scopus (13)
[34] L.W. Ji, C. Saquing, S.A. Khan and X.W. Zhang, Preparation and characterization of silica nanoparticulate–polyacrylonitrile composite and porous nanofibers, Nanotechnology 19 (2008), p. 085605. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (5)
[35] L. Wang, P.D. Topham, O.O. Mykhaylyk, J.R. Howse, W. Bras and R.A.J. Jones et al., Electrospinning pH-responsive block copolymer nanofibers, Adv Mater 19 (2007), pp. 3544–3548. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (16)
[36]
X. Zong, K. Kim, D. Fang, S. Ran, B. Hsiao and B. Chu, Structure and
process relationship of electrospun bioabsorbable nanofiber membranes, Polymer 43 (2002), pp. 4403–4412. Article | PDF (687 K)
| View Record in Scopus | Cited By in Scopus (453)
[37]
Y.B. Cai, Q.F. Wei, F.L. Huang and W.D. Gao, Preparation and properties
studies of halogen-free flame retardant form-stable phase change
materials based on paraffin/high density polyethylene composites, Appl Energy 85 (2008), pp. 765–775. Article | PDF (1070 K)
| View Record in Scopus | Cited By in Scopus (4)
[38]
P. Zhang, Y. Hu, L. Song, J.X. Ni, W.Y. Xing and J. Wang, Effect of
expanded graphite on properties of high-density polyethylene/paraffin
composite with intumescent flame retardant as a shape-stabilized phase
change material, Sol Energy Mater Sol Cells 94 (2010), pp. 360–365. Article | PDF (637 K)
| View Record in Scopus | Cited By in Scopus (0)
Corresponding
authors. Tel.: +86 510 85912007; fax: +86 510 85913100 (Q. Wei), tel.:
+86 510 85912005; fax: +86 510 85912009 (F. Huang). 
