|
| Authors | Nanoparticles and
refrigerants | Parameters | Characterization | Method of stabilization | Inferences |
|
| Liu et al. [40] | Au | R141b | 1 vol% | TEM, dynamic light scattering analysis | — | No discussion on stability |
| Xiao-Min et al. and Park et al. [29, 41] | CNT’s | R22, R123, and R134a | 1 vol% | — | — | No discussion on stability |
| Bartelt et al. [42] | CuO | R134a+oil RL68H | 4 vol% in oil,
0.5, 1, and 2 mass% of suspension in R134a,
avg size: 30 nm | — | Ultrasonic agitation of nanolubricant for 24 h | Flow boiling study |
| Bi et al. [9] | TiO2 and Al2O3 | R134a+mineral oil | 1 mass%,
50 nm | Light transmission ratio index | Ultrasonic agitation | Stable suspension |
| Ding et al. [43] | CuO | R113+RB68EP oil | 40 nm | TEM | No surfactants | Considered to be stable |
| Kedzierski et al. [25] | CuO | R134a (with polyolester) | 1 vol% in polyolester,
size: 30 nm | Light scattering technique | Surfactant and ultrasonication for 24 h | Particles will dispersed after weeks with avg size 35 nm |
| Trisaksri et al. [31] | TiO2 | R141b | 0.01, 0.03, and 0.05 vol% | TEM | Ultrasonication for 6 h | Stable dispersion was found |
| Peng et al. [33] | CuO | R113 | 0.1, 0.2, and 0.5 wt%,
avg size: 40 nm | TEM | Ultrasonic processing for 30 min | Stable dispersion was found |
| Jiang et al. [44] | CNT’s | R113 | Size: 15-80 nm
0.2, 0.4, 0.6, 0.8, and 1 vol% | TEM | Ultrasonic process for 30 min | No discussion
on stability |
| Henderson et al. [34] | SiO2 and CuO | R134a+polyolester | 0.05 and 0.5 vol% of SiO2,
0.02, 0.04, and 0.08 vol% of CuO, | Not mentioned | Hexamethyl-disilazane coated on SiO2, and CuO mixture is ultrasonic agitated for several min | SiO2
is stable with coating.
CuO needs ultrasonic mixing for stable dispersion |
| Peng et al. [26] | Diamond | R113 (oil VG68) | 3 wt% in oil,
5, 10, and 15 wt% of suspension in R113,
size: 10 nm | SEM | Ultrasonication for 12 h | Observed the stable suspension after 12 h |
| Peng et al. [45] | CNT’s | R113+oil VG68 mixture | 1, 3 and 5 wt% of CNT nanolubricant mixed with R113 | TEM | Ultrasonication for 120 min | Stable dispersion was found |
| Bobbo et al. [46] | SWCNH’s and TiO2 | R134a+POE oil | SWCNH’s–100 nm and TiO2–21 nm
0.5 g/L | TEM for SWCNH’s | Ultrasonic vibration for 45 min | No discussion
On stability |
| Kedzierski [47] | Al2O3 | R134a (with polyolester) | 5.6% in polyolester,
0.5, 1, and 2 mass% of suspension with R134a,
size: 20 nm | Light scattering technique | Surfactant and ultrasonication for 24 h | Particles dispersed properly with avg size 10 nm |
| Peng et al. [32] | Cu | R113+oil VG68 | Size: 20, 50, and 80 nm,
0-5 wt% of suspension | TEM | Ultrasonication for 1 h | Stable dispersion was ensured |
| Peng et al. [48] | Cu | R113 | 0.1, 0.5, and 1.0 wt% in R113,
avg size: 20 nm. | TEM, Spectro-photometer | Surfactants: SDS, CTAB, and Span-80 and ultrasonication for 1 h | Found stable for 24 h |
| Peng et al. [49] | Cu, Al, Al2O3, and CuO | R113, R141b, and n-pentane+RB68EP oil | 0.2–1.37 vol%,
size: 20 nm | TEM | No surfactants | No discussion on stability |
| Bi et al. [10] | TiO2 | R600a | 0.1 and 0.5 g/L | Light transmission ratio index | — | Stable suspension |
| Abdel-Hadi et al. [50] | CuO | R134a | Size: 15-70 nm
0.1–1% | — | Mixed by gravity effect | Flow boiling study |
| Mahbubul et al. [51] | TiO2 | R123 | Up to 5 vol%
avg size: 21 nm | Not mentioned | No surfactants | Flow analysis |
| Subramani et al. [52] | Al2O3 | R134a | 0.06 mass% of nanolubricant
avg size: 50 nm | Not mentioned | Ultrasonic agitation for 24 h | Stable dispersion for 3 days |
| Kumar et al. [53] | Al2O3 | R134a+PAG oil | 0.2%
concentration,
size: 40-50 nm | Not mentioned | Magnetic stirrer for mixing and ultrasonic shake for 30 min | Ensured stable dispersion |
| Hu et al. [54] | Cu | R113+oil VG68 | Nanolubricant; 1,3, and 5 wt%,
surfactant; 0-10,000 ppm | TEM | Surfactants: SDS, CTAB, and Span-80 and ultrasonication for 1 h | Stable for 24 h |
| Mahbubul et al. [16, 22] | Al2O3 | R141b | Size: 13 nm
0.5, 1, 1.5, and 2 vol% | TEM | Orbital incubator shaking for 24 h at 240 rpm | Stable suspension was ensured |
| Sun et al. [55, 56] | Cu, Al, Al2O3, and CuO | R141b | 0.1, 0.2, and 0.3 wt% in R141b,
avg size: 40 nm | Visible spectro-photometer | Surfactant: Span-80 and
ultrasonic shaking for 30 min | Dispersion was stable |
| Tang et al. [57] | δ-Al2O3 | R141b | 0.001, 0.01, and 0.1 vol% | SEM | Surfactant: SDBS and ultrasonication for 10 h | Predicted to be stable for 54 days |
| Nephon et al. [30] | TiO2 | R141b | 0.01, 0.025, 0.05, and 0.075 vol%,
avg. size: 21 nm | Not mentioned | Ultrasonication for 3 h | Synthesized just before experiments and found stable |
| Baqeri et al. [58] | CuO | R600a/POE | 0.5, 1, 1.5, 2, and 5 wt% | — | Ultrasonic shaking | Found stable for 12 h |
| Mahbubul et al. [59] | Al2O3 | R141b | Size: 13 nm
0.05–0.15 vol% | SEM, TEM | Mechanical shaking for 24 h at 240 rpm | Proper dispersion of particles |
| Akhavan-Behabadi et al. [60, 61] | CuO | R600a+(oil RL68H) | 0.5, 1, and 1.5 wt%,
avg size: 50 nm | Not mentioned | Ultrasonic shaking for 1 h | Visually ensured stable dispersion |
| Diao, et al. [27] | Cu | R141b | 0.008, 0.015, and 0.05 vol%
avg size: 30 nm | SEM | SDBS and ultrasonic shaking for 8 h | Obtained stabilized suspension |
| Yang et al. [62] | MWCNT’s | R141b | 0.1, 0.2, and 0.3 wt% | Visible spectro-photometer | Surfactant: Span-80 and ultrasonic shaking for 30 min | Stable dispersion was found |
| Kedzierski et al. [63] | Al2O3 | R134a (with polyolester) | 1.6, 2.3, and 5.1 vol% in polyolester,
0.5 and 1 mass% in R134a | Dynamic light scattering technique | Surfactant and ultrasonication for 24 h | Particles dispersed properly with avg size 10 nm |
| Alawi et al. [64] | TiO2 | R123 | 0.5-2 vol%
size: 20 nm | — | — | Flow boiling study |
|
