Mesopore Structure and Composition of Different Kapok Fibers

doi:10.21203/rs.3.rs-1984534/v1

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Mesopore Structure and Composition of Different Kapok Fibers

https://doi.org/10.21203/rs.3.rs-1984534/v1

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To make full use of domestic kapok fiber, the microstructure and composition of Quanzhou kapok were invetigated and compared with the popular Indonesia ceiba. FIB-SEM images showed the similar fine tube structures of both kapok fibers with the wall thickness and hollow ratios of 806.1 nm, 85.56% and 863.3 nm, 82.40% repectively. Mesopores with the average width of 48.247 and 38.758 Å were proved to be slit pores produced by the packing of porous lamellae. Quanzhou kapok was more superior in wall thickness, hollow ratio, specific surface area and pore size which would be better at oil adsorption. Both kapok fibers were primarily composed of cellulose, hemicellulose and lignin. Quanzhou kapok had better thermostability and higher degradation speed than that of Indonesia ceiba. Inside the fiber, cellulose skeletons were in the arrangement of helical ribbon, while amorphous lignin and hemicellulose made up the fibrillar interval and cemented the fibers together. The interstice between the different compositions should be the mesopores. In this paper, the experimental results were discussed and analyzed in detail aiming at microstructure and composition distribution of kapok fiber were further investigated and modelled, which could provide reference values for the applications and product development process of domestic kapok fiber.

kapok fiber

mesopore

microstructure

composition

cellulose

As lofty deciduous leaf arbor, kapok tree is native chiefly to Southeast Asia, Africa, Americas, South and Southwest provinces of China (Editorial Committee of Chinese Flora, Chinese Academy of Sciences, 1984). Due to its high drought stress tolerance, easy artificial propagation and rapid-growth, kapok tree is survivable in harsh environment and often used in landscaping (Li and Chen 1996). Besides, it is a very suitable species for the reforestation to restore degraded forest in Hainan province (Luo et al. 2020). A large area planted trees provide extensive sources of kapok fiber.

Obtained from the fruits of kapok tree, kapok fiber is a natural cellulosic fiber with fine tube structure (Sun et al. 2005, Li 1984). As a single-cell fiber, thin-wall (wall thickniess 1–2 µm), high hollowness (hollow ratio 80–90%), low density (0.29 g/cm³) and hydrophobic-oleophilic properties are the characteristic features of kapok fiber which made it widely utilize as filling, buoyant, thermal insulation and oil absorption materials (Zheng and Wang 2016, Cook 1974, Xiao et al. 2005, Liu 2011, Shi 2009). With better resistance of bacterial, mildew and mite, bedding, hygiene and toilet textiles are produced using kapok fibers (Yan et al. 2015). Rich in nature, environment-friendly and cost-effective make kapok fiber an ideal material in the treatment of marine oil spill and domestic sewage (Zheng 2015).

The main components of kapok fiber are cellulose (35–64.0%), hemicellulose (also called xylan, 22%-45%), lignin (13–22%), water (8–11%), water-soluble substances (4.7%-9.7%), ash (1.3%-3.5%), wax (0.8-3.0%) (Fengel and Przyklenk 1986, Danda and Kolawole 2003). The cell wall of kapok fiber was divided into five layers by Shi et al. (2009). After treatment by alkali or ultrasonic wave, ligin was removed and the residual cellulose became ribbon shaped (Hu et al. 2016, Liu et al. 2019). Experiments by Liu show that physical adsorption was the main sorption mechanism and oil was stored in the lumen of kapok fibers (2020). Many researchers tried to graft lipophilic groups on the surface of kapok fiber to improve its absorption properties (Dong et al. 2016; Wang et al. 2012 a, b; Wang et al. 2013). In our previous study, the mesopore structure was proved in ceiba kapok cell wall and and pore size distributed in 2–40 nm (Yang et al. 2018). The dimensions of Quanzhou kapok and Indonesia ceiba were measured and their oil adsorption performances were also explored (Yang et al. 2022). The oil adsorption and retaining rate of Quanzhou kapok were larger than that of Indonesia ceiba which suggested the further investgation of different microstructures.

In South and Southwest provinces of China, kapok trees are planted massively as trade trees and curtilage afforest. But each May and June, kapok catkins are fluttering in the air which cause distress to the environment and human health. However, Indonesia ceiba fibers are employed in large quantities on domestic market. To take full advantage of local kapok fiber, mesopore structure and composition were studied and compared with Indonesia ceiba fiber in this work.

Materials

Local kapok fiber is the research object manually collected in our college campus in Quanzhou City and its species is Panzhihua kapok. Indonesia ceiba fiber is provided by textile company of Jiangxi province. Their specifications are list in Table 1.

Table 1

Specifications of kapok fibers
Samples	Production place	Year	Color	Average diameter/µm	Average length/mm
Quanzhou kapok	Quanzhou City	2021	faint yellow	15–35	14.5–27.5
Indonesia ceiba	Indonesia	2021	faint yellow	10–30	21.0–34.0

Morphological observation

Scanning Electron Microscope-Focused Ion Beam (FIB-SEM, Helios 5UC) is a combination equipment of ion beam and scanning electron microscope which precise observation is about 50 nm. Cross-sections of kapok fiber were cut by FIB and observed at the magnification of 8000–50000.

Nitrogen adsorption measurements

Each sample (about 0.22 g) was vacumm-dried at temperature150°C for at least 2 h to remove impurities adsorbed before measurement. N₂ adsorptioin-desorption isotherms were obtained at minus 195.644°C and relative pressure (P/P₀) was set at 0.0165–0.1043. Brunauer-Emmett-Teller (BET) model was used to calculate the specific surface area at relative pressure between 0.03 and 0.3. Test parameters are in the following: Equilibration Interval: 5s, Low Pressure Dose: 10.000 cm³/g STP, Cold Free Space: 49.3000 cm³.

Composition analysis

Fourier Transform Infrared Spectroscopy (FTIR) were employed to explore the composition of two kinds of kapok fiber on a Nicolet NEXUS670 spectrometer using DTGS KBr. Samples were scanned 32 times on the resolution of 4000. Thermogravimetric analysis (TG) was used to study the thermal stability of two kinds of kapok fiber. About 6 mg samples were heated from 25 to 510 ℃ at 10.00 ℃/min. Mass changes of different composition with temperature were analyzed through TG and DTG curves.

Mesopore structure of kapok fiber

Morphology analysis

The longitudinal and cross-section views of two fibers were shown in Fig. 1. It can be seen from longitudinal views that both fibers have smooth cylindrical surface with silk like luster. Almost-transparent cell wall indicactes its thin-wall and large-hollow structure. Transversal surface images taken by FIB-SEM shows the oval-shaped cross-section of kapok fiber. Dimensional measurements reveal the major diameter, minor diameter and wall thickness of two fibers. The major and minor diameters of Quanzhou kapok are 22.70 and 20.41µm respectively, while Indonesia ceiba are 23.40 and 15.65 µm. The length of major diameter of Quanzhou kapok is almost equal to its minor diameter and its cross-section is approximately orbicular. Indonesia ceiba is more elliptical as a little squashed by semimanufactures while Quanzhou kapok is not because of hand collecting. The wall thickness of Quanzhou kapok is 806.1 nm, slightly thinner than that of Indonesia ceiba (863.3 nm). Assuming that the fine tube of kapok fiber is a cylinder with uniform thickness, hollowness ratio K can be calculated by Eq. (1). The hollow ratio of Quanzhou kapok is approximately 85.56% and Indonesia ceiba is 82.40% corresponding with other researches.

$$K=\frac{{{A_a}}}{{{A_{\text{b}}}}} \times 100\% =\frac{{({\text{a}} - 2d) \times (b - 2d)}}{{a \times b}} \times 100\%$$

Where A_a is the area of lumen; A_b is the total area of cross-section; a, b and d are the major diameter, minor diameter and wall thickness of oval-shaped section respectively.

Mesopore structure

We all know that there are a variety of pores for air and oil molecule accessing to the lumen of kapok fiber. For further evalution of pore structure of two different kapok fibers, N₂ adsorption-desporption isotherms were emlpoyed and the results are shown in Fig. 2. The curves of both fibers show the same type-Ⅳ adsorption-desorption isotherms, suggesting the open and continuous pores in the cell wall (Wang and Okubayashi 2019, Yang et al. 2013). Monolayer adsorption before inflection point, multilayer adsorption in the middle region, cappillary condendsation phenomenon represented by hysteresis loop are characteristics of mesopore adsorption shown in adsorption-desorption isotherms (Fig. 2(a&b)). Hysteresis loop closes when P/P₀ is about 0.4 indicating the existence of smaller mesopores. The H3 type-hyseteresis loop predicts the typical slit-like pore structure in IUPAC hysteresis classifications (Kimura et al. 2016, Sing et al. 1985).

The pore structures of two kapok fibers are estimated using t-plot analysis showing in Fig. 2(c&d). The position of plots in T-plot can be the criterion for the types of pores. If there is no mesopore, plots are on the straight line passing through the origin. The plots deviate in the upper or downward direction from the straight line indicating the cylindrical or slit pores (Kimura et al. 2016). Consequently, both kapok fibers have slit pores corresponding with the conclusion by H3 hyseteresis loop. Besides, plots in Fig. 2(d) gradually deviate from the straight line meaning the wider size distribution of Indonesia ceiba. A small amount plots of Quanzhou kapok deviating in the upper direction may suggest the presence of a tiny number of cylindrical pores.

The specific volume and size distribution of mesopores in kapok fibers were calculated based on Barrett-Joiner-Halenda (BJH) method as shown in Fig. 2(e&f). Multiple peaks exhibite in size distribution curves which are distributed in 20–400 Å. Centering on 20–40 Å of most sizes also confirms the mesopore struture.

The specific surface area and size distribution were calculated using Eqs. (2), (3) and (4) and the calculations are shown in Table 2. We can see that the surface area, pore volume and size of Quanzhou kapok are larger than that of Indonsia ceiba. In our previous study, the oil adsorption and retaining rate of Quanzhou kapok were larger than that of Indonesia ceiba (Yang et al. 2022). Table 2 give us the explaination.

$\frac{P}{{{V_{\text{a}}}({P_0} - P)}}=\frac{1}{{{V_m}C}}+\frac{{(C - 1)}}{{{V_{\text{m}}}C}}\frac{P}{{{P_0}}}$	(2)
${\text{t}}=\sqrt {\frac{{0.14}}{{\ln ({P_0}/P)+0.034}}}$	(3)
${\text{(d}} - 2t)=\frac{{ - 2\gamma {V_{{\text{mol}}}}}}{{RT\ln ({P_0}/P)}}$	(4)

Where V_a and V_m are adsorbance and saturated extent of monolayer respectively; C is BET contant; t is the thinkcess of multi-layered N₂ molecules adsorbed on the inner sufface of the cylinder; γ is the surface tension of liquid N₂ (8.85 mN/m); V_mol is the molar volume of liquid N₂ (34.7 ml/mol); d is the slit thickness.

Table 2

Pore parameters of two kapok fibers
Samples	BET surface area(m²/g)	Pore volume (cm³/g)	Pore size (Å)	T-plot micropore area (m²/g)
Quanzhou kapok	2.575	3.11⋅10³	48.247	1.5585
Indonesia ceiba	1.825	1.77⋅10³	38.758	0.6715

Formation mechanism of slit structure

These above results strongly suggest that the mesopores of kapok fibers are slit pores. From Fig. 3(a) it can be observed clearly that the cell wall of kapok fiber is multilayered structure. Research revealed that the cell wall of kapok fiber had five layers, including inner skin (IS), tertiary wall (W₃), secondary wall (W₂), primary wall (W₁) and cuticle (S) densified from inside to outside (Zheng and Wang 2014, Shi et al. 2009). The cuticle S is the thinnest and massive compact layer while IS is secondary thinner and the loosest. W₁ has an interlaced fibril-like network prarallel to the fiber axis and the fiberils of W₂ and W₃ are arranged angled or parallel to the fiber axis (Hu et al. 2019). L₁ and L₂ are the transition layer. Besides, three W layers are also made from more minor lamellas. In Fig. 3(b), it can be seen that there is almost no open pore straight up and down in the cell wall. Accordingly, every lamella has mesopores and slit pore structure forms after multilayers are packed together as shown in the model of Fig. 3(c).

Composition structure

FTIR analysis

The identical characteristic groups in FTIR spectra confirm the same compositions of two kapok fibers as shown in Fig. 4. A little bit different in intensities of minority peaks may represent the different percentage of each ingredient. The strong and broad characteristic peak near 3333.11 cm^− 1 is assigned to the stretching vibration of non-free –OH. The absorption peak of hydroxyl group shifts to lower position and its width is enlarged due to three kinds of hydroxyl group of cellulose in different environment and the strong intermolecular hydrogen bond. The peak around 896.90 and 1103.14 cm^− 1 in fingerprint region, which are assigned to anomeric carbon stretching vibration and C–O–H asymmetric stretching vibration, repectively, represent the charateristic groups of cellulose (Xiao et al. 2005, Fan et al. 2020). The absorbance peak near 2916.27cm^− 1 is assigned to the symmetric and asymmetric stretching vibration of –CH₂– and –CH₃. The peak at 1032.18cm^− 1 is due to the the asymmetric stretching vibration of C–O. The absorbance bands around 1596.41 and 1506.56 cm^− 1 are contributed to the aromatic ring carbon skeletal of lingin stretching. The absorbance peak at 1238.32 cm^− 1 is assigned to the stretching vibration of phenolic group. These peaks reveal the presence of ligin. The peak near 1460.04 cm^− 1 is attributed to CH₂ bending vibration in xylan (Zhang et al 2009). The absorption bands at 1732.96 and 1371.32cm^− 1 are the contribution of carbonyl group stretching vibration of ketones, carboxylic groups and esters in lignin and acetyl eser groups in xylan (Wang et al. 2012). The major chemical components of two kapok fibers are cellulose, lignin and xylan concluding from FTIR spectra.

Thermal Analysis

Thermal gravity was adopted to explore the thermostability of two kapok fibers. The consistent TG/DSC/DTG curves indicate the similar thermal properties of two kapok fibers as shown in Fig. 5. In Fig. 5(a&b), the weight losses of two fibers are 5.753% and 2.757% assigning to the volatilization of water and impurities in small content at 25–100℃ corresponding with the water loss peak in DTG curve. The water loss rate of Indonesia ceiba is more than twice as much as Quanzhou kapok meaning the different moisture content of two fibers.

The TG flat curve shows the slow and steady mass loss process prioring to the temperature of the degradation onset (T_onset). An obvious shoulder peak comes out at T_onset and TG curve declines dramatically due to the decomposition of hemicellulose. The characteristic temperatures are list in Table 3. T_onset, epitaxial termination temperature (T_end) and the final temperature (T_f) are determined by extrapolation method, while temperature of the maximum of degradation rate (T_p) can be obtained from DTG curve. T_1/2 is the temperature when half of the weight has decomposed. The range of T_p-T_onset is the main interval of thermosteresis and distinct degradation peaks can be seen in DTG curves at T_p. Indonesia ceiba reaches to the maximum rate at 339.8℃ and its weight loss is 62.598% resulting from the thermal degradation of cellulose and hemicellulose at the moment. While T_p and weight loss of Quanzhou kapok are 341.9 ℃ and 63.450%. Ligin begins to decompose from T_end to T_f which is best at heat resistance among them. The remainders are 10.769% of Indonesia ceiba and 11.809% of Quanzhou kapok corresponding with the content of lignin (13%).

By contrast, the thermal properties of two kapok fibers are approximately identical. In Table 3, the characteristic temperatures of Quanzhou kapok are slightly higher than that of Indonesia ceiba showing the slightly better thermostability. The different range of T_p-T_onset and T_end - T_onset reveal that the degradation speed of Quanzhou kapok is a little higher than that of Indonesia ceiba. For weight loss, the water loss rate of Quanzhou kapok is a half of Indonesia ceiba, but other identical proportions of decompositions indicate that the contents of cellulose, hemicellulose and lignin of Quanzhou kapok is marginally higher than Indonesia ceiba.

DSC curves also can be seen in Fig. 5(a&b). Small endothermic peaks of Quanzhou kapok and Indonesia ceiba appear at 50.9℃ and 47.4℃ respectively corresponding with the water loss peak of DTG curves. Representing the water content, the peak area of Indonesia ceiba is 1454.9 J/g, higher than that of Quanzhou kapok (762.4 J/g). As the temperature rise, almost no crystallization or melting occurs.

Table 3

Characteristic parameters of thermodegradation
Samples	Temperature of thermal degradation (℃)					T_p-T_onset	T_end-T_onset
Samples	T_onset	T_p	T_end	T_1/2	T_f	T_p-T_onset	T_end-T_onset
Quanzhou kapok	297.7	341.9	365.1	339.8	423.1	44.2	67.4
Indonesia ceiba	288.7	339.6	363.2	334.3	412.8	50.9	74.5

Composition model

FTIR and thermal analysis show that kapok fiber is primarily composed of cellulose, hemicellulose and lignin. Due to the wax and fat, kapok fiber has a smooth cylindrical surface (in Fig. 6(a)). As alkali soluble compositions, hemicellulose and lignin are removed after alkali treatment and the wrinkle surface appears as shown in Fig. 6(b) (Lopez et al. 1996, Li et al. 2007, Mancera et al 2011). The residual cellulose molecules work as the skelecton in the form of microfibril bundles. As amorphous materials, lignin and hemicellulose distributes throughout the cellulose fibrils. Besides, a spiral ribbon (Fig. 6(c)) is obtained when hemicellulose and lignin are removed consistent with researches by Hu et al (2016, 2019). Accordingly, it can be concluded that the cellulose fibril skeletons are arranged in ribbons and lignin is filled in the gaps. As short branched chain structure, hemicellulose is usually connected with cellulose through hydrogen bond. The composition model of kapok fiber is shown in Fig. 6(d). The cellulose fibril skeletons are arranged in network, angled or parallel to the fiber axis in W₁, W₂ and W₃ layers separately. The mesopore structure dicussed in this work is the fibrillar interval actually. The interstice between the different compositions should be the mesopores measured by N₂ adsorption method.

In this work, mesopore structure and composition of Quanzhou kapok and Indonesia ceiba were investigated. The multilayer mesopore and composition distribution were modelled and the following conclusions have been drawn.

With thin-wall and large-lumen structure, the cell wall thickness of two kapok fibers are 806.1 and 863.3 nm, while their hollow ratios are 85.56% and 82.40% respectively. Quanzhou kapok has thinner cell wall and larger hollow ratio. The mesopore structure of kapok fiber is slit-like and its pore size is concentrated in 20–40 Å. The average pore sizes of Quanzhou kapok and Indonesia ceiba are 48.247 and 38.758 Å. The specific surface area, pore volume and sizes of Quanzhou kapok are slightly larger than that of Indonsia ceiba. Multi-lamellas with mesopore are packed together and the slit pore structure is formed. Both kinds of kapok fibers are primarily composed of cellulose, hemicellulose and lignin. Quanzhou kapok has better thermostability and higher degradation speed. Cellulose skeletons are in the arrangement of helical ribbon and amorphous lignin and hemicellulose make up the fibrillar interval of kapok fibers and cement the fibers together. The interstice between the different compositions should be the mesopores discussed in this work.

Ethics approval and consent to participate

Not applicable.

Consent for publication

All the authors have approved publication of this manuscript.

Availability of data and materials

The detail data has been in the supplementary materials.

Competing interests

The authors declare no competing financial interest.

Funding

Natural Science Foundation of Fujian Province, China (Grant No. 2021J05187), Quanzhou City Science & Technology Program of China (Grant No. 2020C039R).

Authors' contributions

Not applicable.

Acknowledgements

Natural Science Foundation of Fujian Province, China (Grant No. 2021J05187), Quanzhou City Science & Technology Program of China (Grant No. 2018G011, 2018K002, 2020C039R), the Startup Foundation for Doctors of Quanzhou Normal University (Grant No. H18024, H18028).

The research is financially supported by Natural Science Foundation of Fujian Province, China (Grant No. 2021J05187), Quanzhou City Science & Technology Program of China (Grant No. 2018G011, 2018K002, 2020C039R), the Startup Foundation for Doctors of Quanzhou Normal University (Grant No. H18024, H18028).

Cook JD (1974) Handbook of textile fibres. Merrow Publishing Co Ltd., Watford
Danda B, Kolawole EG (2003) Processibility of nigerian kapok fibre. Indian J Fibre Text 28:147–149. http://doi.org/10.1007/BF02875443
Dong T, Cao SB, Xu GB (2016) Highly porous oil sorbent based on hollow fibers as the interceptor for oil on static and running water. J Hazard Mater 305: 1–7. http://doi.org/10.1016/j.jhazmat. 2015.11.030
Editorial Committee of Chinese Flora, Chinese Academy of Sciences (1984) Flora China (Vol 49, Second Volume). Science Press, Beijing, pp 106–108
Fan JY, Kong XX, Yun YL, Zheng JJ, Zheng LJ, Li W (2020) Preparation and characterization of kapok nano cellulose. Guangdong Chem Indus 47:12–14
Fengel D, Przyklenk M (1986) Studies on kapok 2. chemical investgation. Holzforschung 40:325–330. http://doi.org/10.1515/hfsg.1986.40.6.325
Hu LX, Wang FM, Xu GB, Xu BG (2016) Unique microstructure of kapok fiber in longitudinal microscope image. Text Res J 87:2255–2262. http://doi.org/10.1177/0040517516673334
Hu LX, Yang JZ, Wang FM (2019) Composition and micro-structure analysis of kapok fiber. J of Donghua University (Nat Sci) 45:645–649 + 675
Kimura M, Qi ZD, Isogai A (2016) Analysis of mesopore structures in wood cell walls and pulp fibers by nitrogen adsorption method. Nord Pulp Pap Res J 31:198–204. http://doi.org/10.3183/NPPRJ-2016-31-02-p198-204
Li BR (1984) Encyclopedia (Textile Volume: Kapok). Encyclopedia of China Publishing House, Beijing, pp 4–7
Li Q, Chen HM (1996) Research on introduction and reproduction of bombacaceae plants. Guangdong Landscape Arch 4:10–13. http://doi.org/CNKI:SUN:GDYL.0.1996-04-004
Liu J, Zhang YP, Zhou R (2020) Adsorption characteristics and mechanism of oil by kapok fiber. Tech Text 38:28–33. http://doi.org/CNKI:SUN:CYYF.0.2020-06-006
Liu MX, Hu LX, Shen H, Yang JZ, Wang FM (2019) Composition distribution and morphological structure analysis after alkali treatment of kapok fiber. Shanghai Text Tech 47:1–5. http://doi.org/CNKI: SUN: SFXK.0.2019-08-001
Liu W (2011) Kapok battings and its thermal insulation properties. Dissertation, Donghua Unversity
Li X, Tabil LG, Panigrahi S (2007) Chemical treatments of natural fiber for use in natural fiber-reinforced composites: a review. J Polym Environ 15:25–33. http://doi.org/10.1007/s10924-006-0042-3
Lopez SD, Tissot M, Delmas M (1996) Integrated cereal straw valorization by an alkaline pre-extraction of hemicellulose prior to soda-anthraquinone pulping. Case study of barley straw. Biomass Bioenerg 10:201–211. http://doi.org/10.1016/0961-9534(95)00031-3
Luo JH, Chen B, Chen GW, Tan ZY, Zhang H (2020) High drought stress tolerance and rapid growth of bombax ceiba is suitable for the reforestation to restore degraded forest in Hainan. Nat Sci J Hainan University 38: 247–249. http://doi.org/10.15886/j.cnki.hdxbzkb.2020.0034
Mancera C, Ferrando F, Salvado J, Mansouri N (2011) Kraft lignin behavior during reaction in an alkaline medium. Biomass Bioenerg 35:2072–2079. http://doi.org/10.1016/j.biombioe.2011.02.001
Shi MW, Cui P, Wang FM, Wei AJ (2009) The buoyancy performance of new type fibrous assemblies of kapok. J Xian Polytechnic University 23:101–106
Shi MW, Xiao H, Yu WD (2009) The fine structure of the kapok fiber. Text Res J 80:159–165. http://doi.org/10.1177/0040517508095594
Sing KSW, Everett DH, Haul RAW, Moscou L, Pierotti RA, Rouqerol J, Siemieniewska T (1985) Reporting physisorption data for gas/solid systems with special reference to the determination of surface area and porosity, Pure Appl Chem 57:603–619. http://doi.org/10.1351/pac198557040603
Sun JX, Wang FM, Liu W, Yan GX (2005) Test and analuses of Java cotton & cotton blending yarn property. Cotton Text Tech 33:354–356
Wang C, Okubayashi S (2019) Polyethyleneimine-crosslinked cellulose agerogel for combustion CO₂ capture. Carbohyd Polym 225:1–8. http://doi.org/10.1016/j.carbpol.2019.115248
Wang JT, Zheng YA, Wang AQ (2012) Superhydrophobic kapok fiber oil-absorbent: Preparation and high oil-absorbency. Chem Eng J 213:1–7. http://doi.org/10.1016/j.cej.2012.09.116
Wang JT, Zheng YA, Wang AQ (2012) Effect of kapok fiber treated with various solvents on oil absorbency. Ind Crop Prod 40:178–184. http://doi.org/10.1016/j.indcrop.2012.03.002
Wang JT, Zheng YA, Wang AQ (2013) Investigation of acetylated kapok fibers on the sorption of oil in water. J Environ Sci 25:246–253. http://doi.org/CNKI:SUN:HJKB.0.2013-02-004
Xiao H, Yu WD, Shi MW (2005) Structures and performances of the kapok fiber. J Text Res 26:4–6. http://doi.org/10.13475/j.fzxb.2005.04.002
Xiao H, Yu WD, Shi MW (2005) Charaters and application prospects of kapok fiber. J Donghua University (Nat Sci), 31:121–125. http://doi.org/10.3969/j.issn.1671-0444.2005.02.029
Yang F, Ning ZF, Kong DT, Liu HQ (2013) Pore structure of shales from high pressure mercury injection and nitrogen adsorption method. Nat Gas Geosci 24: 450–455. http://doi.org/CNKI:SUN:TDKX.0. 2013-03-002
Yan XF, Wang Q, Zhou ML, Wang FM (2015) Antibacterial property and antibacterial mechanism analysis of kapok fiber. Cotton Text Tech 43: 18–21. http://doi.org/10.3969/j.issn.1001-7415.2015.03.004
Yang ZL, Yan JJ, Wang FM (2018) Pore structure of kapok fiber. Cellulose 25: 3219–3227. http://doi.org/10.1007/s10570-018-1767-6
Yang ZL, Li QL, Guan FW, Jiang DW, Wang FM, Qiu YP, Zhang CY (2022) Morphlogical Characteristics and oil-sorption prpperties of Quanzhou kapok fiber and fruit. J Donghua University (Nat Sci) 48:14–20. http://doi.org/10.19886/j.cnkidhdz.2021.0431
Zhang YH, Fan QG, He JX (2009) Structure and thermal properties of kapok fiber. Shandong Text Sci Tech: 48–52. http://doi.org/10.3969/j.issn.1671-6906.2008.03.012
Zheng YA, Wang AQ (2014) Kapok Fiber: Structure and Properties (Chap. 6). In: Hakeenm KR et al. (eds.), Biomass Bioenerg: Processing and properties. http://doi.org/10.1007/978-3-319-07641-6_6
Zheng YA, Wang JT, Zhu YF, Wang AQ (2015) Research and application of kapok fiber as an adsorbing material: A mini review. J Environ Sci 27:21–32. http://doi.org/10.1016/j.jes.2014.09.026

No competing interests reported.

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Mesopore Structure and Composition of Different Kapok Fibers

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Abstract

Figures

Introduction

Experiments

Materials

Morphological observation

Nitrogen adsorption measurements

Composition analysis

Results And Discussion

Mesopore structure of kapok fiber

Morphology analysis

Mesopore structure

Formation mechanism of slit structure

Composition structure

FTIR analysis

Thermal Analysis

Composition model

Conclusion

Declarations

References

Additional Declarations

Supplementary Files

Status:

Version 1

\(\frac{P}{{{V_{\text{a}}}({P_0} - P)}}=\frac{1}{{{V_m}C}}+\frac{{(C - 1)}}{{{V_{\text{m}}}C}}\frac{P}{{{P_0}}}\)	(2)
\({\text{t}}=\sqrt {\frac{{0.14}}{{\ln ({P_0}/P)+0.034}}}\)	(3)
\({\text{(d}} - 2t)=\frac{{ - 2\gamma {V_{{\text{mol}}}}}}{{RT\ln ({P_0}/P)}}\)	(4)