Table 1.

Overview of structural and physicochemical properties of silicas obtained from the diatoms T. punctigera and T. weissflogii cultured at two distinct salinities and chemically prepared silicas at comparable salinities

Species	Salinity, psu*	Growth rate, div·day−1	BET-specific surface area, m2·g−1	BJH pore dimension, nm	Pore dimension(s), nm†			Fractal dimension, D‡
					EM	SAXS	USAXS	SAXS	USAXS
T. punctigera	20	0.264	12	10	—	10.3	62.8	3.3	2.5
				27–35	25–35	33.0	287
	33	0.273	27	3	2.9	13.5	72.1	3.6	2.5
				30–45	30–40	38.5	379
T. weissflogii	20	0.247	32	3.6	—	8.5	476	2.9	2.3
				35–45	25–35	28
	33	0.238	39	3.7	3.6	10	600	3.2	2.5
				32–40	35–40	35
Synthetic silica	0	NA	462.3	3.6	ND	ND	ND	ND	ND
	20	NA	298.5	3.6	ND	8.0	ND	2.6	ND
				5.3
Synthetic silica	33	NA	266.8	3.8	ND	8.5	ND	3.0	ND
				33

—, not detected; NA, not applicable; ND, not determined.

*psu, practical salinity units.

^†Pore dimensions were calculated from transition points between straight scattering regions in the SAXS and USAXS spectra (22, 23).

^‡Fractal dimensions were determined from the slopes of the straight scattering regions in the SAXS and USAXS spectra (22, 23).