Optimization of Process Conditions of Cotton Fabric Dyeing with Nettle Leaf Extract for Antibacterial Application Using Central Composite Design

Figures & data

Table 1. The amount of natural dye from nettle leaf at different extraction conditions.

Std	Run	Time (Hr.)	M:L (g/L)	Efficiency (Yield (%))
12	1	36	20	36
1	2	24	10	24
6	3	53	20	48
7	4	36	6	24
9	5	36	20	36
8	6	36	34	40
10	7	36	20	40
13	8	36	20	38
11	9	36	20	36
2	10	48	10	42
3	11	24	30	26
4	12	48	30	44
5	13	19	20	20

Table 2. Analysis of Variance (ANOVA) for the amount of dye for different dye extraction variables.

Source	Sum of Squares	Df	Mean Square	F-value	p-value
Model	802.44	2	401.22	37.68	<.0001	significant
A-Time	714.44	1	714.44	67.09	<.0001
B-Material to Liquor ration	88.00	1	88.00	8.26	.0165
Residual	106.48	10	10.65
Lack of Fit	93.68	6	15.61	4.88	.0734	not significant
Pure Error	12.80	4	3.20
Cor Total	908.92	12

Table 3. Colour strength values in different parameter combinations.

Run	Presoak (min.)	Temp. (^℃)	Conc. (g/L)	DL	Da	Db	dE	K/S
1	55	65	20	−7.35	1.19	8.17	11.05	0.9952
2	40	80	10	−6.06	0.06	8.59	10.51	0.4283
3	55	65	20	−7.16	1.27	8.33	11.06	1.1129
4	55	86	20	−11.04	1.73	8.97	14.33	1.0636
5	55	65	20	−7.15	1.03	8.81	11.39	1.1234
6	34	65	20	−6.51	0.94	8.23	10.54	1.0205
7	55	44	20	−6.58	0.92	8.82	11.04	0.8893
8	70	80	30	−5.97	0.47	8.11	10.08	1.6021
9	55	65	20	−7.77	1.02	8.83	11.81	1.0486
10	70	50	30	−8.32	1.43	8.78	11.91	1.5825
11	55	86	20	−10.1	1.46	8.72	13.42	1.0861
12	76	65	20	−7.14	1.06	7.89	10.69	0.9648
13	55	65	6	−4.79	0.22	7.31	8.74	0.0328
14	55	65	34	−7.9	1.02	10.36	13.07	1.8893
15	55	65	34	−7.77	0.83	10.5	13.09	1.9893
16	70	80	10	−2.17	0.19	2.54	3.35	0.4083
17	40	50	30	−6.68	0.71	6.4	9.28	1.6525
18	40	50	10	−1.27	0.37	0.83	1.56	0.4927
19	76	65	20	−7.53	1.15	8.09	11.11	1.0152
20	55	43	20	−5.35	0.7	8.38	9.97	0.8849
21	55	65	20	−8.25	1.38	9.42	12.6	1.0173
22	34	65	20	−7.68	1.19	8.9	11.82	0.9803
23	40	80	30	−4.82	0.39	5.95	7.67	1.6701
24	55	65	20	−7.24	1.11	8.93	11.55	0.9304
25	70	50	10	−3.14	0.57	2.79	4.24	0.4219
26	55	65	6	−7.06	0.6	7.84	10.57	0.0344

Table 4. Analysis of Variance (ANOVA) for K/S value.

Source	Sum of squares	df	Mean square	F-value	p-value
Model	6.45	3	2.15	455.76	<.0001	significant
A-presoak	0.0042	1	0.0042	0.8904	.3556
B-temperature	0.0152	1	0.0152	3.22	.0865
C-powder	6.43	1	6.4300	1363.17	<.0001
Residual	0.1038	22	0.0047
Lack of Fit	0.0696	12	0.0058	1.70	.2052	not significant
Pure Error	0.0342	10	0.0034
Cor Total	6.55	25

Figure 1. FT-IR spectra of the extracted dye, dyed sample with sodium alginate mordant, and without mordant, respectively.

Table 5. Values of light, washing, and rubbing fastness of cotton fabrics dyed by the pre-mordanting method.

	Wash fastness
		Staining on white		Rubbing Fastness
Dyed samples	Change in color	Cotton	Polyester	Dry	wet	Light fastness
Without mordant	1–2	2	4–5	3–4	1–2	3
aluminum sulfate	3–4	4	4–5	3–4	3–4	4
Myrobalan	3–4	5	4–5	4	4	4–5
Sodium alginate	4	5	4–5	5	4–5	5

Figure 2. Bacterial growth conditions on the control fabric.

Table 6. Bacterial reduction test results for the treated fabric.

Run	Presoak (Min.)	Temp. (^OC)	Conc. (g/L)	Antibacterial reduction
				S. aureus E. coli
1	55	65	20	88	92
2	40	80	10	73	73
3	55	65	20	88	91
4	55	86	20	86	89
5	55	65	20	87.6	90.2
6	34	65	20	87	89.8
7	55	44	20	89	90.4
8	70	80	30	89	89
9	55	65	20	89	89.7
10	70	50	30	92	92
11	55	86	20	80	80
12	76	65	20	83	83.8
13	55	65	6	48	52.2
14	55	65	34	96.5	98
15	55	65	34	96.5	98
16	70	80	10	72.8	76
17	40	50	30	93.1	94
18	40	50	10	76	77.5
19	76	65	20	84	84
20	55	43	20	80.3	81.6
21	55	65	20	87	86
22	34	65	20	78	79.6
23	40	80	30	93	93.5
24	55	65	20	86	86
25	70	50	10	68	70
26	55	65	6	46	50

Figure 3. 3D response surface plots for the effects of extracted powder concentration, temperature, and pre-soak time on S. aureus after cotton fabric dyeing.

Figure 4. Response surface plots for the effects of extracted powder concentration, temperature, and presoak time on E. coli after cotton fabric dyeing.

Figure 5. Gram-negative and Gram-positive bacteria growth conditions on the treated cotton fabric.

Figure 6. Bacterial growing conditions for both E. coli and S. aureus on the treated sample after one and five washes, respectively.

Figure 7. Bacterial growing conditions for both E. coli, and S. aureus on the treated sample after 10 and 15 washes, respectively.

Table 7. Bacterial reduction (%) test results of wash durability for the treated fabrics.

			Sample
Bacteria	Control	Treated fabric	After 1 wash	After 10 wash	After 10 wash	After 15 wash
S. aureus	0	96.5	96.5	91	85	80
E. coli	0	98	98	94	90	84