Controlling Foam Morphology of Poly(methyl methacrylate) via Surface Chemistry and Concentration of Silica Nanoparticles and Supercritical Carbon Dioxide Process Parameters

Table 2

Summary of the cell density and cell size measurements for all samples used in the current study. 𝑇 is the foaming temperature and 𝑃 is the saturation pressure.

Sample label	Surface modification (%)	Concentration (wt%)	𝑇 (°C)	𝑃 (MPa)	Cell Density^† (10^9 cm^−3)	Cell Diameter^† (μm)
PMMA	—	—	40	8.97	0.75±0.05	9.62±5.22
B	—	0.85	40	8.97	0.57±0.09	5.36±4.33
B	—	2.50	40	8.97	0.67±0.29	6.90±4.14
F	~73	1.29	40	8.97	57.1±10.4	1.62±0.40
F	~73	3.16	40	8.97	248±12	1.29±0.29
FF	>100	1.38	40	8.97	132±16	2.10±0.80
FF	>100	3.20	40	8.97	248±23	1.45±0.54
FF*	>100	2.9	40	8.97	380±91	1.38±0.44
FF*	>100	2.9	65	8.97	478±32	1.19±0.37
FF*	>100	2.9	65	13.45	478±43	1.23±0.34
FF*	>100	2.9	65	17.93	444±48	1.52±0.56
FF*	>100	2.9	75	8.97	464±30	1.06±0.32
FF*	>100	2.9	85	8.97	412±23	1.12±0.37
FF*	>100	2.9	85	13.45	398±44	1.52±0.37
FF*	>100	2.9	85	17.93	400±14	1.52±0.43

*These samples were all processed from the same silica synthesis batch.
^†Standard deviation is given.