Alternative Eco-friendly Treatment of Hollow Cellulosic Fiber-Based Hybrid Composites for Remarkable Reactive Dyeing

Egyptian Chorisia hollow fibers have been blended with cotton waste, polyester waste, and raw bamboo at various ratios and weft counts using open-end spinning. The blended fabrics of hybrid composites were subjected to atmospheric plasma, pectinase, and lipase enzyme treatments, as well as the substitution of all hazardous chemicals, as sustainable alternatives to traditional alkaline scouring. The impacts of the treatments on the hollow-based fabrics' hydrophilicity, surface morphology, and color performance have been discussed. Pretreatment is associated with considerable weight loss (~ 12%) and a wetting time of less than 5 s which represents adequate absorbency of the composite. The enzymatic treatment contributed to looser arrangement of the fibrils which indicates an effective elimination of lignin and hemicellulose. The crystalline sections were greatly influenced by enzymatic treatment, providing effective decrease of cellulose crystallinity by about 30–40% as revealed by X-ray diffraction (XRD) measurements. Compared to conventional scouring, bio-scouring discharges significantly less effluent. The treated composite using either enzyme or plasma pretreatment method produced about at least 300% higher color yield (K/S) and 100% enhanced dye fixation (% F) than the untreated fabric. The lipase pretreatment without subsequent to atmospheric plasma treatment could be enough to achieve the highest hydrophilicity and color performance level under the experimental conditions.


Introduction
Hollow-based fiber is considered a single-cell cellulosic fiber is thought to have the highest level of hollowness (80-90%) among natural fibers [1,2].It is able to maintain a porosity of more than 80% thanks to its hollow structure.However, some of the hollow-based fiber's unique characteristics, as it is so short and light, have long prevented its use as a textile raw material [2,3].
The large lumen and waxy surface of Egyptian Chorisis spp. is not conducive to the access of hydrophilic coloring agents, and as a result, kapok fibers exhibit reduced dyeing efficiency [3,4].On the other hand, these characteristics make it possible to be potentially applied as oil-absorbing material [5,6].
The interaction between lignin, other non-celluloses and cellulose, a large lumen and a waxy surface prevent some of the hydroxyl groups from being accessible to dye molecules, giving Chorisis spp. a hydrophobic feature and low dyeing effectiveness.Thus, Chorisis spp.must first be treated to make it hydrophilic before it is dyed.There have been limited investigations of the pretreatment of kapok fibers and their dyeing properties till now [3,4].
For industrial scouring, sodium hydroxide, surfactants, and chelators are typically utilized at high temperatures [7,8].Even though chemical pretreatment of textiles is crucial, since it gives the material its characteristics, the standard scouring processes for cellulose materials use a lot of energy, water, and chemicals.Additionally, a lot of waste is produced, which adds to the waste water's COD/BOD burden [9].Therefore, the hunt for ecologically friendly processes to lessen environmental contamination is sparked by ecological concerns.Plasma treatment is a quick, easy, convenient, and economical procedure.Surface cleaning, surface activation, surface etching, cross-linking, chain scission, oxidation, grafting, and deposition of materials are all possible with plasma treatment [4,8,10,11].Enzymes are now being used more frequently in the area of plant fiber modification, as a result of their environmentally friendly application and the highly specific reactions they catalyze.Noncellulosic impurities of the cuticle and primary wall, such as waxes and pectin, can be eliminated by the action of enzymes under mild reaction circumstances as an alternative to treatment with sodium hydroxide [8,[11][12][13][14].Since enzymes only work on specific targets, there is no fiber damage during treatment.Additionally, baths with enzymatic treatments have been less polluted than baths with sodium hydroxide scouring.The use of various enzymes for textile pretreatment has been discussed in numerous reviews and scientific articles [10,15,16].
Recently, environmentally friendly pretreatment of kapok and dyeing techniques has been used with enzymes and plasma treatment [4].After being treated with atmospheric plasma, pectinase and lipase enzymes significantly increased the hydrophilicity level, whiteness, and color strength values.
Compared to traditional alkali treatment, these methods provide several benefits, such as reduced prices, reduced environmental issues, preserved fiber strength and structure, and compatibility with other processes [4].Additionally, both of them are more environmentally friendly options, because they only required one bath, whereas the standard alkaline approach needs three baths, including the cationization procedure [3].
The current study's objective is to address environmental issues with hollow cellulosic fabric-based polyester/cotton/ bamboo hybrid composite scouring using environmentally friendly alternatives to traditional alkaline scouring by pretreating with pectinase and lipase enzymes, either separately or in combination with atmospheric plasma for remarkable reactive dyeing and substituting all hazardous chemicals in our previous investigation.Therefore, in this study, we proposed sustainable scouring process which could be used as a novel source for pretreatment of hollow cellulosic-based fabrics before textile coloration.We optimized the different treatments to investigate the wettability behavior of the hollow cellulosic fabric-based polyester/cotton/bamboo hybrid composite.The terms of crystallinity were investigated by XRD and Fourier transform infrared spectra (FTIR).The eco-friendly characteristics of the conventional and bioscouring with respect to effluent load for biological oxygen demand test (BOD), chemical oxygen demand test (COD), and total dissolved solids (TDS) have been studied.The effect of pretreatment on dyeing performance exhaustion and fixation behavior of the hollow cellulosic fabric-based polyester/cotton/bamboo hybrid composite was determined.Finally, the colorfastness properties of the dyed composite were evaluated.

Materials
Egyptian Chorisia fibers were collected from Aswan, Egypt and are shown in Fig. 1.Manually and simply, the fibers and seeds were separated.As has proceeded with natural fibers, neither the opening nor the cleaning steps are necessary with these fibers.The Chorisia fibers, which have relative fiber lengths of 2, 1.3, 3.2, and 3.8 cm, were blended with cotton waste, polyester waste, and raw bamboo.Carded cotton (giza 45) and polyester continuous filaments that were extracted from the yarn cone remnants were employed in this work and used as received (Fig. 2).All other chemicals and reagents used were of laboratory grade.

Tensile Strength and Elongation of Fabrics
Tensile strength and elongation of produced fabrics were evaluated by standard ASTM-D5035-Standard Test Method for Breaking Force and Elongation of Textile Fabrics (Strip Method), using Instron tester apparatus Model: 3345K2068.

Conventional Scouring Process
3 g/L NaOH is used to prepare stock for conventional scouring.Since the water utilized in the wet processing may contain hard-water chemicals, 1 g/L sequestering agent, QUEST-AMP, based on amino trimethylene phosphonic acid (ATMP), supplied by Sarax, India, can be employed.Additionally, 1 g/L of detergent, Egyptol BL, non-ionic detergent (based on nonyl phenol ethoxlate), was supplied from Starch and Brewer's Co. Alexandria, Egypt and 2 g/L of the wetting agent, based on polyethylene glycol, RESIS-COUR LFSCL, Resil Chemicals Pvt. Ltd., Bangalore, India.The fabrics were then properly submerged in the solution and agitated for 1 h at 100 °C using M:L = 1:10.After the completion of the scouring process, the samples were correctly squeezed, and then rinsed twice with hot and cold water, respectively.The samples were then dried using a lab oven drying.

Surface Improvement of Hollow Cellulosic-Based Woven Fabrics Using DC Air Glow Discharge Plasma
In both the presence and absence of Chorisia, woven fabricbased polyester/cotton/bamboo hybrid composites were first scoured with (2 g/L) Egyptol BL for 20 min.at 90 °C.They were then rinsed in cold tap water and air-dried.Plasma treatment was performed using a low-pressure DC glow discharge plasma device in the air, with variable time intervals of 30 and 60 s on one side and both sides.The plasma system that is used for the textile treatment is the virtual cathode configuration, as shown in Scheme 1.The virtual cathode arrangement of the plasma system is utilized to treat textiles.To create a potential difference large enough for the gas breakdown to occur, a DC power source (1 kV-200 mA) is required, and a 6 k rheostat is used to regulate the discharge current.The higher electrode acts as the cathode with a 5.2 cm diameter, while the lower stainless steel hollow ring electrode serves as the anode, and the gap separation is approximately 3 mm.An evacuated stainless steel chamber with side windows is home to both electrodes and is used for various measurements.A cooling cycle is fitted over the cathode and a needle valve was utilized to modulate the gas pressure.

Enzymatic Pretreatment of Hollow Cellulosic-Based Woven Fabrics
The untreated and pretreated fabrics by DC air glow discharge plasma have been subjected to treatment with different concentrations of pectinase/lipase enzymes, dispersed solutions (3, 5, 7, and 9%) with liquor ratio 1:25 at PH 7 using phosphate buffer solution 1.0 M provided by Sigma for 20 min.at temperature 55 °C.After 20 min., the temperature of the same bath was raised to 80 °C for 10 min for enzyme inactivation.The samples were rinsed with distillate water to get rid of any remaining enzyme, and then air-dried.

Weight Loss Determination
After plasma/enzyme pretreatment, % weight loss (WL) was calculated using the following formula: where w 1 and w 2 are the weights of the fabric before and after treatment, respectively.To completely remove any remaining moisture, treated hollow cellulosic-based woven fabrics were desiccated for 24 h after air drying before being weighed.

Wettability Drop Test
Using AATCC Test Method 79-2000, the wettability of the treated hollow cellulosic-based woven fabrics was assessed both before and after the scouring.The duration of time it takes for a sample of fabric to absorb a specific volume of distilled or deionized water (typically one drop) serves as a measure of the fabric's absorbency.Sample conditioning is crucial, because the amount of moisture that remains on the sample before measurement can significantly affect the findings of the absorbency test.The sample is positioned vertically at the required distance from the end of a burette filled with water while being held under a fixed tension (mounted on an embroidery frame).A stopwatch is used to measure the amount of time that passes between the water drop touching the sample's surface and the point at which it is fully absorbed by the sample (the liquid reflection no longer exists).To obtain an average, a sample should be tested at least five times.
Wetting time of 5 s or less is considered to be adequate absorbency of the cotton fabrics.
Scheme 1 Schematic diagram for plasma pretreatment system

Contact Angle Measurement
To determine the hydrophilicity of the hollow cellulosicbased woven fabrics, the contact angle was measured after photographing by an SDL Video Camera using Rame hart goniometer model no 400.

Surface Morphology
The surface morphology of the treated hollow cellulosicbased woven fabrics was investigated using a scanning electron microscope (SEM) (Quanta FEG 250, USA).

FTIR Spectra
To examine the changes in the primary characteristic groups of non-cellulosic impurities in the composite after treatment with plasma/enzyme, the treated hollow cellulosic-based woven fabrics were subjected to FTIR spectra (in KBr pellet), primarily carried out on a Spectrum BX FTIR spectrometer (PerkinElmer, USA).The FTIR absorption data were also used to see the changes in the structure of hollow cellulosic fabric-based polyester/cotton/bamboo hybrid composite like TCI (Total Crystallinity Index), CI-IR (crystallinity index), and HBI (Hydrogen-Bond Intensity) parameters.
The TCI parameter was measured by comparing the absorbance value at wavenumber 1373 and 2900 cm −1 (A 1373 /A 2900 ) from the FTIR spectrum.The ratio of absorbance values at peak 1360.69 and 662.8 cm −1 is the parameter for the CI-IR value (A 1427 /A 894 ).The HBI parameters were determined by the wavenumber ratio at the peak of 3400 and 1320 cm −1 (A 3400 /A 1320 ) [15,16].

Effluent Treatment
The comparison of effluent load for COD, BOD, and TDS between the bio-scouring process (lipase, pectinase, and lipase + plasma) and conventional alkaline scouring of composite has been carried out in term of COD, BOD, and TDS in in the effluent water after the completion of scouring process.COD test can be used to easily quantify the amount of organic contaminants in water and wastewater.It was measured by KIT COD/1500 by POT Dichromate APP Nanocor 300D and heating block Nanocolor R-8.BOD was measured using OxiTop measuring system, with an Oxitop IS 12, Germany.TDS is measured as a volume of water with the unit milligrams per liter (mg/L) using lab water analysis.COD, BOD, and TDS (mg/L) were done according to the experimental steps detailed in the Standard Methods [19][20][21].

Reactive Dyeing of Treated Fabrics
The treated and untreated samples were dyed with 2% reactive dye on the weight of hollow cellulosic-based woven fabrics (o.w.f.).Dyeing was performed according to the specified conventional reactive dyeing [14].The liquor ratio for dyeing treatments was 1:25 at 60 °C for 60 min.Finally, neutralization (with 1 g/L acetic acid 10 min), washed, and then air-dried.

Color Strength
Spectral reflection measurements of the dyed fabrics were carried out using a recording filter spectrophotometer.The color intensity expressed as K/S values of the dyed samples were calculated using the Kubelka-Munk equation where R is the decimal fraction of the reflectance of the dyed substrate, and R 0 is the decimal fraction of the reflectance of the undyed substrate.The dyed samples' color intensity was calculated using the undyed substrate, S is the scattering coefficient, and K is the absorption coefficient.

Dye Exhaustion and Fixation
Spectrophotometric analysis was used to decide the exhaustion rate (% E) of the dyes as well as the dye fixation rate (% F) as was calculated from Eqs. ( 1) and (2), respectively [22] where A 0 , A t , and A s are the absorbance of the initial dye bath, the dye bath after dyeing, and the absorbance of the soaping liquor, respectively, at λ max of reactive dye.

Effect of Chorisia Fibers on the Tensile Strength and Elongation of Produced Fabrics
Table 1 demonstrates that at counts 10/1 and 6/1 at the same picks, the weft direction tensile strength of the fabrics with Chorisia is somewhat higher than that of the Chorisia-free fabrics.This could be explained by the crystallinity index of the Chorisia fibers, which made the molecular chains aligned more closely to each other as well as the high ratio of molecular chains tend to make them parallel to the orientation axis of the fibers [7].The tensile strength increases with an increase in the Chorisia fiber ratio up to a certain limit and then decreases, as seen at count 4/1.Because there are more Chorisia fibers in the thick count and there is more sliding inside the yarn, the fibers are not aligned parallel to the yarn axis, which reduces the tensile strength.It is also evident that Chorisia-containing fabrics elongate more in the weft direction than chorisia-free fabrics do at counts 10/1, 6/1, and 4/1 at the same picks.This may be due to the low ratio of crystalline part and the increasing of the amorphous region in Chorisia fiber [24].
To examine the impact of pretreatment on tensile strength, the thin counts (6/1 and 10/1) are regularly treated to individual pretreatments with plasma and enzymes (data not shown).It is important to note that in our prior study [3], conventional alkaline scouring increased tensile strength compared to untreated ones.This was consistent with the composite's plasma treatment.The tensile strength was raised by 20% by plasma pretreatment in this work, which is identical to our earlier data for the chemical scouring of hollow-cellulosic-based fibers.This might be the result of the plasma treatment's lack of effectiveness in removing non-cellulosic components like lignin and hemicellulose, but its ability to partially destroy the waxy coating and clean the surface [4].On the other hand, the individual enzyme treatment decreases the tensile strength by 25%.This may be because the enzymes can completely remove the waxes that have become loosened as well as degrade the non-cellulosic materials that make up the bulk structure of the composite [4,25].This could in turn increase the amorphous regions in the composites, which would have reduced their tensile strength.

Weight Loss and Wettability of Fabric
Bio-scouring of hollow cellulosic fabric-based polyester/ cotton/bamboo hybrid composites with individual lipase or pectinase or subsequent to DC air glow discharge plasma treatment was characterized by the fabric weight loss to evaluate the overall degradative effect of different treatments.Figure 4A demonstrates that compared to the other treatments, the individual lipase or plasma pretreatment led to a marginally greater loss of weight.It can be a result of the elimination of wax and pectin, which are thought to be the most crucial factors during the scouring process.It is important to note that in this investigation, the plasma treatment had no significant effect on the whole removal of a waxy coating, but it might partially remove the layer by etching and cleaning the surface.Accordingly, unlike other researchers' findings [4], this study for a slightly hydrophobic composite did not require plasma treatment prior to the enzymatic treatment, nor was it crucial to break and remove the waxy layer for enzymes to react with the composite effectively.In general, as will be shown in the next tests, a single enzyme treatment could drastically alter the surface of the composite.It was evident that a considerable weight loss could be accomplished (12% for 10/1 Ne and 9% for 6/1 Ne), when bio-scouring is carried out by lipase which is showing more activity compared to pectinase (~ 10% for 10/1 Ne and ~ 7% for 6/1 Ne).Fortunately, the thin counts of produced fabrics from the blending Chorisia fibers greatly affects the scouring action and acquired higher weight loss than the thick counts.Thus, they do not impede their future application and are fit to meet the wearability and comfort requirements of textiles.
The surface of the Chorisia fibers in the composite is coated with a waxy layer and non-cellulosic materials which is giving a super hydrophobic property to the composite.Therefore, removing the wax from Chorisia is essential for improving wettability before reactive dyeing.Figure 4B demonstrated that as compared to the untreated sample, specific enzyme or plasma treatments greatly increased the hydrophilicity of the hollow cellulosic fabric-based polyester/cotton/bamboo hybrid composite.The wetting time of 5 s or less was provided after treatment which represents adequate absorbency of the composite.Individual samples treated with lipase were discovered to be more hydrophilic than samples treated with plasma or pectinase.This might be because the lipase enzyme, which leads to stronger bioscouring action, is more stable under treatment conditions than pectinase.Additionally, a limited etching of the fiber surface and/or partial removal of the surface wax are two additional effects of plasma treatment.The contact angle data are consistent with this observation.For the untreated samples with weft counts of 6/1 and 10/1, respectively, the contact angle of the untreated fabric was observed after 10 s. of drop test, as shown in Fig. 4C.The results indicated that the thin-count samples (10/1 Ne) of composites were found to be more hydrophilic than thick-count samples (6/1 Ne).This will have a positive impact on the wearability and comfort requirements of textiles.Due to the high hydrophilicity of treated hollow cellulosic fabric-based polyester/cotton/ bamboo hybrid composites as was described in the wettability and weight loss section, their contact angle cannot be measured precisely by this method.The contact angle is a dynamic simulation value, since the droplet is instantly absorbed by the sample as soon as it hits its surface (in less than a second).By the way, the weight loss test and the wettability test are sufficient measures of their high hydrophilicity in comparison to untreated samples.

Surface Morphology
To investigate the modifications that occurred on the surface of composites after the treatments, SEM images of untreated and treated hollow cellulosic fabric-based polyester/cotton/bamboo hybrid composites were examined.SEM was used to see if there was any difference between treated and untreated surfaces that could be seen.Figure 5 displays the samples' SEM figures.It can be seen from the images that the untreated samples either 6/1 or 10/1 (Fig. 5a, b) appeared multicellular circular fibrils, compactly arranged are connected by pectin and the outer surface of fibers consisting of pectin, lignin, and waxy materials forms a smooth surface on the outer surface area.However, after various treatments, the surface morphologies have changed (Fig. 5c-e).The surface of the samples revealed a wavy surface structure and became rough after plasma and enzyme treatment, coupled with varying degrees of wrinkles, micro-cracks, and tiny grooves.These modifications may have resulted from the partial removal of non-cellulosic material by an enzyme and the etching effect of plasma.It could be also seen that the treatments increase the interspace between the circular fibrils and result in a looser arrangement of the fibrils as compared to the untreated ones which could afford extra space for solutions to fill the spaces between the circular fibrils.This was consistent with drop test results to express the high hydrophilicity of treated samples compared to untreated ones [5].

FTIR Analysis of Hollow-Based Fabrics
By comparing the intensity of distinctive peaks at specific bands of pectin, lignin, and waxes, FTIR spectroscopy is used to assess the changes in the quantity of non-cellulosic components after treatment.Figure 6A shows that the untreated samples have the characteristic strong band at 3320 cm −1 in the spectrum due to the hydrogen-bonded OH stretching.The elimination of non-cellulosic material and the distortion of OH-bonding caused the band to expand and appear at 3340 cm −1 after enzyme or plasma treatment [26].It is evident that both the untreated and treated samples show the recognizable strong band at 1028 cm −1 , which could be identified for the cellulose's C-O bonds.Additionally, untreated fabric has two peaks at 2920 and 2851 cm −1 representing the presence of waxes.After enzymatic and plasma treatments, the peak at 2920 cm −1 has become less sharp, while the one at 2851 cm −1 has nearly completely vanished which indicates that no wax could have remained on the surface of the composite.Peaks at 1740 and 1641 cm −1 have declined or are nearly invisible after enzymatic or plasma treatments, indicating the presence of free fatty acids and esterified carboxylic groups in wax and pectin, respectively [27].These peaks are contaminants that can be utilized to characterize the scouring process, including wax and pectin, both of which contain m-carboxylate (COO) functional groups.There is additionally a critical diminishing in the characteristic peaks at 1231 cm −1 for enzymatic (9%) or plasma-treated samples, indicating a decrease in hemicellulose and lignin, and the cleavage of the aromatic ring in lignin.It is important to note that enzyme concentration has a significant impact and is essential for the total removal of non-cellulosic components [27].The presence of a characteristic band at 1231 cm −1 for hemicellulose and lignin without remarkable change in 5% of enzyme-treated samples proves this assumption.The values of the TCI, CI-IR, and HBI substrates were then determined using the data from the FTIR spectra, as given in Table 2. Cellulose crystallinity was assessed using the values of TCI and CI-IR.Both of TCI and CI-IR values decreased drastically after enzyme pretreatment.This is consistent with the crystallinity discovered using XRD patterns by Segal [18] or Lorentzian [17].While the TCI value of composites processed with 9% lipase enzyme decreased dramatically, that of hollow cellulosic-based woven fabrics with plasma pretreatment at 60 s showed a minor divergence.It indicates that pretreatment using 9% lipase can change cellulosic structures from cellulose of type II (an ordered structure) to cellulose of type II, which is not an organized structure (more amorphous form).The HBI values of composite were slightly different, but they increased after pretreatment with an enzyme.The rise of HBI values after enzymatic pretreatment is due to the release of hemicellulose and lignin polymer, which preserve the cellulose structure.As a result, intra-and intermolecular hydrogen bonds of cellulose become more exposed in the substrates.

XRD Analysis of Hollow-Based Fabrics
XRD analysis was performed to investigate the effect of plasma and enzyme treatment on the crystallinity of treated hollow cellulosic fabric-based polyester/cotton/bamboo hybrid composites (Fig. 6B).For untreated, plasma-treated, and enzyme-treated samples, the XRD patterns clearly show that the typical major three diffraction peaks of cellulose I emerge in the positions of 2θ close to 15° (101), 22.4° (002), and 35.9° (004) for untreated, plasma-treated, and enzymetreated samples [4].Additionally, it is plain to observe that the results of X-ray diffraction demonstrate that after plasma or enzyme treatments, the crystal phase of treated samples remained unchanged.In other words, the XRD pattern and position of the distinctive peak associated with a partial crystalline were similar in the curve morphologies of the treated and untreated samples.The enzyme-treated samples showed a significant decrease in intensity for the characteristic peak 22.4° (002), which is associated with the crystalline area, while the plasma-treated samples showed a little increase in intensity compared to the untreated one.In light of this, the samples' crystallinity index (CI) was calculated in accordance with the Segal method [18].Hollow cellulosic fabric-based polyester/cotton/bamboo hybrid composites with no treatment, plasma treatment, or enzyme treatment were found to have CI-Segal, of 42.5, 47, and 26%, respectively [4,28].The degree of crystallinity (X c ) followed the same trend of Segal method as is shown in Table 2. X c and D have been decreased drastically after pretreatment with 9% lipase enzyme which are consistent with data of XRD patterns.The higher considerable decrease of crystallinity after enzyme treatments is not similar with the research trends to bio-scouring of cellulosic materials that have been reported by many researchers [4,28,29].They have reported an increase in CI after the enzymatic treatment of individual cellulosic materials.This observation in our study indicated that the enzymatic treatment is not influential the hydrolysis of amorphous regions of the composites and has a high efficacy toward the crystalline regions.This may be attributed to the presence of bamboo which has significantly greater moisture absorption and ventilation, since the cross-section of the fiber is packed with numerous microgaps and micro-hole [30,31].This could improve enzyme penetration during bio-scouring and reduce the high lignin content that decreases the enzyme activity in the crystalline regions.Generally speaking, the plasma treatment showed a slight increase in crystallinity which contrasts with the results of the bio-scouring of individual kapok described by Bozaci [4].This may be ascribed to the resistance effect of polyester macromolecules and bamboo on the surface of the composite for the etching effect of plasma treatment, which would otherwise make the composite more hydrophilic, as well as the hydrolysis of amorphous areas.This could be seen from the increase of distinctive peak, 35.9° (004) after plasma treatment which suggests a relative increase in the crystalline phase due to the removal of amorphous  compounds such as amorphous cellulose as well as lignin and hemicelluloses.It is interesting to note that the distinctive peaks of control polyester, which displayed maxima at 2θ values of 17.5°, 23°, and 25.7°, disappeared.This may be due to the composites' increased cellulosic content acting as a shield.

Effluent Comparison
The comparison of effectiveness between conventional and bio-scouring by pretreating with pectinase and lipase enzymes, either separately or in combination with atmospheric plasma, has been done with respect to effluent load for BOD, COD, and TDS.The difference between the BOD, COD, and TDS of discharged water from conventional scouring and bio-scouring is shown in Table 3 which can be shown more prominently in Fig. 7.It is obvious that the BOD, COD, and TDS in the case of bio-scouring either separately or in combination with atmospheric plasma are much less than the conventional scouring.Bio-scouring reduces the amount of BOD, COD, and TDS in the effluent by about 75.5, 48, and 46.6%, respectively.The use of harsh chemicals in the conventional chemical scouring, such as reducing agents, detergents, sequestering agents, and wetting agents, is largely to blame for the rise in BOD, COD, DO (dissolved oxygen), and TDS levels in effluent water as well as unwanted pressure they place on the environment.In light of this, the use of enzymes in the wet processing of textiles has opened up new avenues for research and provided a material that is probably eco-friendly and offers a good answer to the issue of highly hazardous chemicals that pollute the environment.Enzymes typically function quite effectively at low temperatures.When compared to conventional process, it reduces energy usage significantly.Contrary to harsh chemically treated fabrics (may damage human skin), bio-scoured fabrics are fully safe for human health [32,33].

Dyeing Performance of Pretreated Fabrics
The color strength of a dye is a proportion of its ability to impart color to other materials.It is used to determine the level of color saturation in a dyed fabric.Since it primarily depends on the color preparation circumstances, it is not a physical constant.This characteristic, which can be stated as a color strength value (K/S) [34,35] is characterized by the absorption in the visible region of the spectrum.As well as the hydrophobic characteristic of polyester fabric and its minimal moisture recovery can be a drawback for specific applications like dyeing and finishing [35][36][37].In light of this, the composites underwent enzyme or plasma treatment and were then dyed with reactive dyes.It is clear that the treatment had disturbed the waxy layer and the impurities of the composite surface and greatly increased the hydrophilicity, color strength, exhaustion, and dye fixation compared to the untreated samples, irrespective of reactive dye as is indicated in Figs. 8, 9, and 10.
The results showed that the pretreatment has a positive impact on the dyeability and color fixation of composite using reactive dyestuffs.In this instance as well, the K/S value and dye fixation of the individual lipase enzymepretreated samples is higher than that of the pectinase-or plasma-pretreated samples.This distinction might be the result of its stability and potency in the removal of hydrophobic non-cellulosic materials of composites, hemicelluloses, and lignin which restrict the existence of the hydroxyl groups on the cellulose chain for reactive dye fixation [4].The resistance effect of bamboo and polyester  macromolecules on the composite's surface may be responsible for the color fixation, which has an average value of 85% and does not exceed 90%.The wettability of the composite and likely the moisture regain of the enzyme-treated polyester were enhanced significantly compared to the untreated, which may account for the reasonable color fixation for pretreated composites that included polyester and have a low affinity for reactive dye.This can be attributed to the hydrolytic activity of enzymes in aqueous media, which results in the formation of hydrophilic niches, specifically carboxylic and hydroxyl groups, along polyester macromolecules [38].
It is worthy to mention that, unlike other researchers who detailed the pretreatment of kapok prior to reactive dyeing [4], the individual enzyme pretreatment does not require the prior plasma pretreatment for the composite.They reported the improvement of kapok in a green way using atmospheric plasma, together with pectinase and lipase enzymes.In other words, the hollow cellulosic fabric-based polyester/cotton/ bamboo hybrid composites could be individually pretreated with plasma or enzyme prior to reactive dyeing, and these pretreatments are proven and effective methods for enhancing the color output of the composite.They are both more sustainable alternatives in contrast to the ordinary alkaline method.
The durability of colors has been investigated on treated blended fabrics which were subjected to washing and light fastness evaluation after one washing cycle.According to the assessment results shown in Table 4, pretreatment composites colored with reactive dyes had greater washing or light fastness than untreated samples, regardless of the kind of reactive dye.This may be attributed to the improved adhesion of reactive dyes to the surface of the composite and the substantial increase brought on by surface modification through plasma or enzyme pretreatment.In this regard, the treated samples exhibit good wash and light fastness qualities ranging from 4 to 5 and from 5 to 6, respectively.
In view of the above outcomes a few points may be concluded; (a) the presence of Chorisia positively affected the blend of cotton waste, polyester waste, and pure bamboo, and succeeded in eliminating all drawbacks related to the mechanical and comfort properties of blended fabrics in our previous examination [31]; (b) this study takes into account the use of cotton and polyester fiber wastes and the major difficulty in recycling textile wastes which limits the regenerated products for low-cost markets, such as second-hand clothing and basic fiber content.This work could provide alternative solutions for the recycling of fibrous wastes generated from post-industrial wastes using reasonable and economical operations through the blending with the Chorisia fibers to produce a variety of marketable and high-value products; (c) the hollow cellulosic fabric-based polyester/ cotton/bamboo hybrid composites might be individually processed with plasma or enzyme.These pretreatments are tried-and-true techniques for enhancing the composite's hydrophilicity and color yield.All enzymes used in this study were commercial grades, having the advantages of easy handling and storage when compared to the pure enzymes used in other studies.As a result, the suggested eco-friendly treatment alternative might be simply implemented on an industrial scale.In contrast to the standard alkaline approach in our prior investigation [3], they are both more environmentally friendly choices.As indicated by other studies for the pretreatment of kapok before reactive dyeing and the individual enzyme pretreatment, the prior plasma pretreatment is not necessary for the individual enzyme pretreatment; (d) in contrast to our earlier investigation [3], it was discovered that the thin-count treated composite samples were more hydrophilic and had a higher color yield.As a result, they were qualified as composites  containing cotton and polyester wastes could be recycled for their further application to meet the wearability and comfort standards of textiles.The blending of fiber wastes with the Chorisia fibers regenerates products with a high-value application using reasonable and economical operations.

Conclusions
This work may offer new approaches for recycling fibrous wastes using reasonable and cost-effective processes through the blending with Chorisia hollow fibers processes to create a range of high-quality, marketable goods.Pretreatment techniques that have been successfully used to increase the hydrophilicity and color yield of hollow cellulosic fiberbased hybrid composites include atmospheric plasma and enzymatic treatment.They offer more environmentally friendly substitutes for traditional alkaline scouring.Prior to reactive dyeing, the hollow cellulosic fabric-based polyester/cotton/bamboo hybrid composites could be individually pretreated with plasma or enzyme, although the individual enzyme pretreatment is not required, as was the case with the kapok pretreatment described by other researchers.The enzymatic treatment shows a high efficiency toward the crystalline sections of the composites but does not effect on the hydrolysis of the amorphous regions, providing an acceptable absorbency of the composite (less than 5 s of wetting time), and an effective 30-40% reduction in crystallinity, as determined by XRD.

Fig. 2
Fig. 2 Chemical structure of the dye used

Fig. 3
Fig. 3 Produced hollow cellulosic-based woven fabrics at different counts and fiber formulations

Fig. 4
Fig. 4 Effect of alternative eco-friendly treatments on A weight loss, B wettability, and C contact angle of hollow cellulosic fabric-based polyester/cotton/bamboo hybrid composite

Fig. 6 A
Fig. 6 A FTIR spectra and B XRD pattern of untreated, lipasetreated, and plasma-treated hollow cellulosic fabric-based polyester/ cotton/bamboo hybrid composites

Fig. 7
Fig. 7 Comparison of BOD, COD, and TDS of discharged water between conventional scouring and bio-scouring

Fig. 8
Fig. 8 Effect of alternative eco-friendly treatments of hollow cellulosic fabric-based polyester/cotton/bamboo hybrid composites on the color strength of dyed fabrics with a reactive yellow 23, b reactive red 31, and c reactive red 195

Fig. 9
Fig. 9 Colored fabrics of treated and untreated hollow cellulosic fabric-based polyester/cotton/bamboo hybrid composites dyed with reactive dyes

Table 1
Effect of Chorisia fibers on the tensile strength and elongation of produced fabrics