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. Author manuscript; available in PMC: 2022 Dec 1.

Published in final edited form as: Microporous Mesoporous Mater. 2020 Jul 14;308:110454. doi: 10.1016/j.micromeso.2020.110454

Table 4.

Chemical shifts (CS) and relative peak areas of MBGs obtained by²⁹Si and³¹P NMR. For each MBG, the silica network connectivity <Qⁿ> is also included.

Sample	²⁹Si							³¹P
	Q⁴		Q³		Q²			Q¹		Q⁰
	CS ppm	Area^a (%)	CS ppm	Area^a (%)	CS ppm	Area^a (%)	<Qⁿ>	CS ppm	Area^a (%)	CS ppm	Area^a (%)
0% Cu_HNO ₃	−112	72.0	−103	27.5	−97	0.5	3.71	−4.5	10.4	2.1	89.5
2.5% Cu_HNO ₃	−112	67.6	−102	31.2	−96	1.0	3.66	−4.5	19.4	1.9	80.6
5% Cu_HNO ₃	−112	64.1	−106	33.9	−95	2.0	3.62	−5.4	21.2	2.2	78.8
0% Cu_HC1	−111	84.1	−102	12.0	−95	3.8	3.8	−8.5	29.9	1.8	70.0
2.5% Cu_HCl	−111	81.9	−102	12.7	−98	5.3	3.76	−2.1	8.3	1.9	91.7
5% Cu_HC1	−112	64.6	−105	30.4	−98	4.9	3.59	−2.1	9.6	1.9	90.4

^a

Areas of the Qⁿunits were calculated by Gaussian deconvolution. The relative populations were expressed as %.