Degrading Natural Armor of Wool: Triple-Synergistic Scale Degradation via Limited Swelling, Disulfide Bond Reduction, and Controlled Proteolysis
降解羊毛天然护层：通过有限膨胀、二硫键还原和可控蛋白水解实现三重协同脱鳞

Ran Li, Yuting Zhou, Man Zhou, Ping Wang, Qiang Wang, and Yuanyuan Yu*
李冉，周宇婷，周曼，王平，王强，和余媛媛*

Cite This: https://doi.org/10.1021/acssuschemeng.5c04547
引用此文献：https://doi.org/10.1021/acssuschemeng.5c04547

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Abstract 摘要

Wool fabrics are susceptible to issues related to felting as a result of their surface scales, which significantly impact their usability. Traditional chlorinated shrink-proof finishing is effective but it produces organic halogen pollutants, which cause significant environmental risks. This study aimed to develop an effective and eco-friendly wool shrink-proof finishing process with an innovative combination of lithium bromide ( LiBr ), glycerol monomercaptoacetate (GMT), and protease (Savinase Ultra 16 XL). These ingredients work synergistically to precisely remove wool scales through a two-stage “steam-batch” process. The study systematically investigated the synergistic mechanisms of $LiBr -$ induced microexpansion of fiber cortex, GMT cleavage of disulfide bonds, and hydrolysis of scale keratins by proteases. The combined use of $10 g / L LiBr, 10 g / L GMT$ , and $6 U / mL$ protease endowed the wool fabric with a promising shrink-resistance property, achieving a felting shrinkage from 11.58 to $2.88 %$ and a fabric strength retention rate of $95 %$ . Compared to the traditional maceration method, this treatment system significantly reduces water and energy consumption while meeting the standards of machine washing. This innovative steam-batch system reduces water use by around $80 %$ compared to traditional maceration. By molecular-level synergy of swelling-reduction-hydrolysis, it overcomes the contradiction between efficiency, environmental protection, and cost inherent in the traditional protease shrinkage prevention process.
羊毛织物由于其表面鳞片结构，容易受到毡化问题的困扰，这对其可用性产生了显著影响。传统的氯化防缩整理方法虽然有效，但会产生有机卤素污染物，造成严重的环境风险。本研究旨在开发一种有效且环保的羊毛防缩整理工艺，通过创新性地结合溴化锂（LiBr）、单硫醇乙酸酯（GMT）和蛋白酶（Savinase Ultra 16 XL）这三种成分。这些成分协同作用，通过两阶段的“蒸汽浸泡”工艺精确去除羊毛鳞片。本研究系统地探究了 $LiBr -$ 诱导的纤维皮质微膨胀、GMT 对二硫键的断裂以及蛋白酶对鳞片角蛋白的水解的协同机制。 $10 g / L LiBr, 10 g / L GMT$ 和 $6 U / mL$ 蛋白酶的联合使用赋予了羊毛织物优异的防缩性能，使毡化收缩率从 11.58 降至 $2.88 %$ ，织物强力保持率为 $95 %$ 。与传统的浸泡法相比，该处理体系显著降低了水和能源消耗，同时满足机洗标准。这项创新的蒸汽批次系统与传统浸泡工艺相比，可节水约 $80 %$ 。通过膨胀-减胀-水解的分子级协同作用，它克服了传统蛋白酶缩水预防工艺中效率、环保与成本之间的固有矛盾。

KEYWORDS: lithium bromide, reductant, protease, wool fiber, green textile engineering
关键词：溴化锂、还原剂、蛋白酶、羊毛纤维、绿色纺织工程

1. INTRODUCTION 1. 引言

Wool fabrics possess several desirable qualities, including resilience, softness, and moisture absorption. They are often used for woven high-grade textiles. However, during daily use and laundering, wool fabric exhibits a discernible shortcoming in terms of dimensional stability.

^{1, 2}

This quality deficiency can have a substantial impact on the functionality and practical application of wool fabrics. This phenomenon is attributed to the directional friction effect (D.F.E.) of the scale layer on the surface of the wool fiber

^{3}

(Figure 1a). The D.F.E., in conjunction with mechanical external forces and wet swelling stresses, leads to the directional migration of the fibers.

^{4}

During the washing process, this microscopic mechanism leads to a significant reduction in the macroscopic size of the fabric due to the interlocking of the scales. This phenomenon directly affects the usability and lifespan of the wool product.

^{5}

Consequently, the effective removal of scales from wool fibers has been a subject of considerable interest among researchers in the field of textile field. In addition, this research direction is also of interest to researchers in the field of wool protein reuse.
羊毛织物具有多种优良特性，包括弹性、柔软性和吸湿性。它们通常用于织造高档纺织品。然而，在日常使用和洗涤过程中，羊毛织物在尺寸稳定性方面表现出明显的缺陷。

^{1, 2}

这种质量缺陷对羊毛织物的功能性和实际应用具有重大影响。这种现象归因于羊毛纤维表面鳞片层的定向摩擦效应（D.F.E.）

^{3}

（图 1a）。D.F.E.与机械外力和湿胀应力共同作用，导致纤维发生定向迁移。

^{4}

在洗涤过程中，这种微观机制由于鳞片的交锁作用，导致织物宏观尺寸显著减小。这种现象直接影响羊毛产品的可用性和使用寿命。

^{5}

因此，有效去除羊毛纤维上的鳞片一直是纺织领域研究人员关注的课题。此外，这一研究方向也引起了羊毛蛋白再利用领域研究人员的兴趣。

Chlorinated shrink-proofing treatments are widely employed in industrial production due to their economic advantage and
氯化防缩处理因其经济优势，在工业生产中广泛应用
substantial efficacy in preventing shrinkage. However, it is important to note the inherent limitations of this technology.

^{6}

The release of adsorbable organic halogenated compounds (AOX) during the process can induce irreversible impairment to aquatic ecosystems and soil microbial communities. Moreover, protein degradation resulting from chlorination can readily lead to a reduction in fabric whiteness.

^{7}

This conflict between environmental concerns and process benefits has led to an increased focus on the development of new chlorine-free methods for wool scale removal, including resin methods, plasma methods, bioenzymatic methods, etc. The resin method is employed to reduce DFE by allowing the deposition of polymer onto the fiber surface. Currently, polyurethane resins, such as Bayer Synthappret BAP, are more
在防止缩水方面具有显著效果。然而，需要注意的是这项技术的固有局限性。

^{6}

在过程中释放的吸附性有机卤化物（AOX）会诱导水生生态系统和土壤微生物群落的不可逆损害。此外，由氯化引起的蛋白质降解会轻易导致织物白度的降低。

^{7}

环境问题与工艺效益之间的这种冲突导致了人们对开发无氯羊毛鳞片去除方法的新关注，包括树脂方法、等离子体方法、生物酶方法等。树脂方法通过允许聚合物在纤维表面沉积来降低 DFE。目前，如 Bayer Synthappret BAP 的聚氨酯树脂等。

Figure 1. (a) Structure of wool fibers and the directional friction effect (D.F.E.). (b) Schematic of the synergistic effects of LiBr, GMT, and protease on wool fibers. © Steam-batch treatment for wool fabrics.
图 1. (a) 羊毛纤维的结构和方向摩擦效应（D.F.E.）。(b) LiBr、GMT 和蛋白酶对羊毛纤维协同效应的示意图。© 羊毛织物的蒸汽批次处理。
commonly used. However, a significant problem with wool fabrics finished with these resins is that they adversely affect the handle properties of the fabric. Plasma contains a large number of reactive particles that can physically and chemically interact with the wool surface, leading to etching.

^{8}

However, this treatment is quite limited and often necessitates additional treatments, such as resins or proteases. Researchers employed airborne low-temperature plasma to pretreat wool, significantly enhancing its wettability and facilitating the binding of enzyme molecules to wool protein chains.

^{9}

These methods have shown effective treatment results in experimental settings; however, in practical production, challenges such as operational complexity, high equipment requirements, and unstable outcomes have hindered their industrialization.
通常情况下，这些树脂处理方法被广泛使用。然而，使用这些树脂处理羊毛织物的一个显著问题是它们会损害织物的手感特性。等离子体含有大量活性粒子，这些粒子可以与羊毛表面进行物理和化学相互作用，导致蚀刻。然而，这种处理方法相当有限，通常需要额外的处理，例如树脂或蛋白酶。研究人员采用空气中的低温等离子体对羊毛进行预处理，显著提高了其润湿性，并促进了酶分子与羊毛蛋白链的结合。这些方法在实验环境中显示出有效的处理结果；然而，在实际生产中，操作复杂性、高设备要求以及结果不稳定等挑战阻碍了它们的工业化。

Enzymatic treatment has been identified as a promising approach for the controlled removal of wool scales. This method has been shown to have significant environmental benefits, making it a viable option for sustainable textile management.

^{10, 11}

However, the intricate network of densely cross-linked disulfide bonds present within the scales of wool fiber significantly limits the catalytic efficiency of the protease. In comparison with the CMC layer, which is distinguished by a sulfur content of less than

3 %

and a loosely organized structure, the protease demonstrated a relative chemical inertness toward the highly cross-linked scale layer.

^{12}

The significant disparity in the hydrolysis rates between the scale layer and the CMC layer of wool fiber has been shown to not only reduce the effectiveness of scale removal from the fiber but also lead to other concerns, including a decrease in the
酶处理已被确认为一种用于可控去除羊毛鳞片的有效方法。该方法已被证明具有显著的环境效益，使其成为可持续纺织管理的一种可行选择。然而，羊毛纤维鳞片内部存在的密集交联二硫键网络显著限制了蛋白酶的催化效率。与硫含量低于

3 %

且结构松散的 CMC 层相比，蛋白酶对高度交联的鳞片层表现出相对的化学惰性。

^{12}

羊毛纤维鳞片层与 CMC 层之间显著的水解速率差异已被证明不仅降低了鳞片从纤维中去除的有效性，还可能导致其他问题，包括降低
uniformity of the fabric surface finishing and a reduction in the strength of the fiber.

^{13, 14}

In order to enhance the efficiency of protease degradation of wool scales, the researchers employed protease in conjunction with various reagents and techniques to break the disulfide bond cross-links between protein molecules.

^{15}

Researchers using urea to swell wool needed to treat it for 3 h at a concentration of 0.5 M and at

50^{\circ} C

, which resulted in increased costs and energy consumption.

^{16}

Furthermore, have used reducing agents such as sodium hydrogen sulfite (

{NaHSO}_{3}

), mercaptoacetic acid (TGA), and Tris(2-carboxyethyl)phosphine (TCEP) in combination with high concentrations of a chaotropic agent (e.g., urea) to cleave disulfide bonds in protein.

^{17, 18}

However, these methods often involve the use of excessive reagents, high energy consumption, and the production of significant amounts of wastewater, which contradicts the principles of green chemistry.

^{19}

Therefore, enhancing the efficiency of wool scale hydrolysis while minimizing its environmental impact continues to be a significant challenge that requires resolution. In addition, enzyme modification has been shown to increase the molecular weight and particle size of the protease, thereby regulating its hydrolysis on the surface of wool fiber, minimizing loss of fiber strength.

^{13, 20}

However, the complexity and expense of the process of enzyme modification have impeded the industrialization of this method.

^{2, 21}

织物表面整理的均匀性以及纤维强度的降低。

^{13, 14}

为了提高蛋白酶降解羊毛鳞片的有效性，研究人员采用蛋白酶与各种试剂和技术结合，以断裂蛋白质分子之间的二硫键交联。

^{15}

使用尿素使羊毛膨胀的研究人员需要将其在 0.5 M 浓度下处理 3 小时，这导致了成本和能耗的增加。

50^{\circ} C

此外，还使用了还原剂，如亚硫酸氢钠（

{NaHSO}_{3}

）、巯基乙酸（TGA）和三(2-羧乙基)膦（TCEP），与高浓度的 chaotropic 试剂（例如尿素）结合，以断裂蛋白质中的二硫键。

^{16}

然而，这些方法通常需要使用过量的试剂，能耗高，并产生大量废水，这与绿色化学的原则相悖。

{NaHSO}_{3}

因此，在尽量减少其环境影响的同时提高羊毛鳞片水解的效率，仍然是一个需要解决的重大挑战。此外，酶改性已被证明可以增加蛋白酶的分子量和颗粒尺寸，从而调节其在羊毛纤维表面的水解作用，最大限度地减少纤维强度的损失。

^{13, 20}

然而，酶改性过程的复杂性和成本阻碍了该方法的工业化。

^{2, 21}

In this research, a novel LiBr -GMT-protease system was developed for the efficient removal of scales from the surfaces of wool fiber. A novel two-stage wool shrink-proof finishing process was explored by LiBr /GMT steam and protease batch
在本研究中，开发了一种新型 LiBr-GMT 蛋白酶系统，用于高效去除羊毛纤维表面的鳞片。通过 LiBr/GMT 蒸汽和蛋白酶分批处理，探索了一种新型两阶段羊毛防缩整理工艺。
processing. LiBr has been shown to induce microswelling of the scale layer through hydrogen bond competition, while GMT has been demonstrated to cleave the disulfide bonds within the scale layer (Figure 1b). The application of proteases in batch processing inhibits the thermal movement and the diffusion properties of the proteases, restricting their activity to the scales on the surface of wool fibers and minimizing damage to the fiber body. The synergistic effect of LiBr and GMT allows the LiBr concentration to be reduced to

10 g / L

and the total amount of chemicals used to be significantly reduced. In addition, the “LiBr/GMT steam-protease batch” finishing process in this study had low water consumption and no AOX contaminants. The felting shrinkage of wool fabrics treated by this process was

\leq 3 %

, which meets the standard of “machine washable”, and the retention rate of fabric strength was

\geq 95 %

. Through molecular-level synergy of

LiBr /

GMT - protease and “steam-batch” process innovation, this technology resolves the contradiction between efficiency, environmental friendliness, and cost in the wool shrink-proofing process, providing a practical and feasible technical pathway for the sustainable improvement of the wool process (Figure 1c).
处理过程中，LiBr 已被证明通过氢键竞争诱导鳞片层发生微观膨胀，而 GMT 已被证实能断裂鳞片层内的二硫键（图 1b）。在批量处理中应用蛋白酶会抑制其热运动和扩散性能，将其活性限制在羊毛纤维表面的鳞片上，从而最大限度地减少对纤维体的损伤。LiBr 和 GMT 的协同效应使得 LiBr 浓度可降低至

10 g / L

，同时显著减少了化学品的总用量。此外，本研究中采用的“LiBr/GMT 蒸汽-蛋白酶批量”整理工艺具有低耗水量且无 AOX 污染物。经该工艺处理的羊毛织物毡缩率为

\leq 3 %

，符合“可机洗”标准，织物强力保持率为

\geq 95 %

。通过

LiBr /

GMT - 蛋白酶的分子级协同作用与“蒸汽批次”工艺创新，该技术解决了羊毛防缩工艺中效率、环保性与成本之间的矛盾，为羊毛工艺的可持续改进提供了切实可行的技术途径（图 1c）。

2. MATERIALS AND METHODS
2. 材料与方法

2.1. Materials. The woven pure merino wool fabric (

180 g / m^{2}

) was supplied by Shandong Nanshan Co. (China). Lithium bromide (LiBr) was purchased from Sinopharm Chemical Reagent Co. (China). Glycerol monomercaptoacetate (GMT) was acquired from Guangzhou Shouyi New Research Material Co., Ltd. Methylene blue (AR) and casein (AR) were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. (China). A protease of Savinase Ultra 16XL, with an enzyme activity of

9000 U / mL

, was purchased from Novozymes (China). Lanasol Red CE was acquired from Huntsman Co.
2.1. 材料。纯美利奴羊毛织物 (

180 g / m^{2}

) 由山东南山公司（中国）提供。溴化锂 (LiBr) 购自国药集团化学试剂有限公司（中国）。单硫醇丙二酸甘油酯 (GMT) 由广州寿怡新材料有限公司提供。亚甲基蓝 (AR) 和酪蛋白 (AR) 购自上海阿拉丁生化科技有限公司（中国）。Savinase Ultra 16XL 蛋白酶，酶活性为

9000 U / mL

，购自诺维公司（中国）。Lanasol Red CE 由亨斯曼公司提供。
2.2. Treatment of Wool Fabric with LiBr/GMT-Protease. Solution A consisted of LiBr/GMT solutions ( pH 6 ) containing

10 g /

L of

LiBr, 10 g / L

of GMT, and

0.5 g / L

of a penetrating agent (JFC6). Solution

B

was a protease solution ( pH 8 ) made with

6 U / mL

of Savinase Ultra 16XL. First-step processing (pad-steam): the wool fabrics were submerged in solution A at room temperature for 30 s , then the fabrics were passed through a vertical two-roll padder (Weida Machinery Co., Ltd., Shaoxing, China) to obtain

95 \pm 1 %

pick-up. The wet wool samples were then treated with steam at

90^{\circ} C

for 520 min at atmospheric pressure. Subsequently, the fabrics were thoroughly washed to remove residual

LiBr / GMT

. Second-step processing (pad-batch): the wool fabrics were submerged in solution B for 30 s , and the fabrics were passed through a vertical two-roll padder to obtain

95 \pm 1 %

pick-up and placed at

30^{\circ} C

in a temperature-controlled oven for

6 - 24 h

. Finally, the treated fabrics were washed and dried.
2.2. 使用 LiBr/GMT 蛋白酶处理羊毛织物。溶液 A 由 LiBr/GMT 溶液（pH 6）组成，含有

10 g /

L 的

LiBr, 10 g / L

GMT 和

0.5 g / L

的渗透剂（JFC6）。溶液

B

是蛋白酶溶液（pH 8），使用

6 U / mL

Savinase Ultra 16XL 配制。第一步处理（浸轧蒸化）：羊毛织物在室温下浸入溶液 A 中 30 秒，然后将织物通过垂直双辊轧车（Weida Machinery Co., Ltd., 绍兴，中国）获得

95 \pm 1 %

吸率。湿羊毛样品然后在

90^{\circ} C

大气压下用蒸汽处理 520 分钟。随后，织物彻底洗涤以去除残留

LiBr / GMT

。第二步处理（浸轧堆置）：羊毛织物在溶液 B 中浸渍 30 秒，然后通过垂直双辊轧车获得

95 \pm 1 %

吸率，并放置在

30^{\circ} C

温度控制烘箱中处理

6 - 24 h

。最后，处理后的织物进行洗涤和干燥。

For comparison, the wool fabrics treated separately with LiBr , GMT, and a mixture of LiBr and GMT using the pad-steam method are labeled as L , G , and

L / G

, respectively. Fabrics treated with protease through the pad-batch process are designated as P. In addition, the fabric treated with steam-batch is referred to as L/G-P.
为了比较，分别使用 LiBr、GMT 和 LiBr 与 GMT 混合液通过浸轧-蒸化法处理的羊毛织物分别标记为 L、G 和

L / G

。通过浸轧-批次法使用蛋白酶处理的织物标记为 P。此外，使用蒸化-批次法处理的织物称为 L/G-P。
2.3. Characterization. 2.3.1. Protease Activity. The methodology for assessing protease activity was modified from the established assay technique.

^{22}

Casein was used as a model substrate to investigate the effect of temperature on protease activity. A

1 %

casein solution and a

1 %

protease solution were individually prepared using Tris- HCl buffer at pH of 8 . The protease solutions were subjected to varying temperatures for a specified time. A volume of 1 mL of protease solution was combined with 1 mL of casein solution, and the resulting mixtures were then incubated at

40^{\circ} C

for 10 min . The reaction was then terminated by adding 1 mL of trichloroacetic acid. The mixtures were centrifuged at 8000 g for 10 min , and the absorbance of the supernatant was measured at 275 nm using a UV-vis spectropho-
2.3. 表征。2.3.1. 蛋白酶活性。评估蛋白酶活性的方法基于已建立的测定技术进行修改。使用酪蛋白作为模型底物来研究温度对蛋白酶活性的影响。使用 Tris-HCl 缓冲液（pH 8）分别制备

1 %

酪蛋白溶液和

1 %

蛋白酶溶液。蛋白酶溶液在不同温度下处理指定时间。1 mL 蛋白酶溶液与 1 mL 酪蛋白溶液混合，所得混合物然后在

40^{\circ} C

下孵育 10 分钟。通过加入 1 mL 三氯乙酸终止反应。混合物在 8000 g 下离心 10 分钟，使用紫外-可见分光光度计在 275 nm 处测量上清液的吸光度。
tometer (Mapada, China). The maximum activity of protease was defined as

100 %

.
显微镜 (Mapada, 中国)。蛋白酶的最大活性定义为

100 %

。
2.3.2. Fabric Properties. Felting shrinkage of the wool fabrics was measured according to IWS TM 31, utilizing a Y(B) 089D fully automatic shrinkage testing apparatus (Darong, China). The calculation of the felting shrinkage was performed based on eq 1.
2.3.2. 织物性能。根据 IWS TM 31 测量羊毛织物的毡缩率，使用 Y(B) 089D 全自动缩率测试仪 (Darong, 中国)。毡缩率的计算基于公式 1。

felting shrinkage (%) = \frac{S_{0} - S_{1}}{S_{0}} \times 100 %

where

S_{0}

was the original area of the samples.

S_{1}

was the area of the samples after a specific wash program.
其中

S_{0}

是样品的原始面积。

S_{1}

是样品经过特定洗涤程序后的面积。

Tensile strength of the wool fabrics was tested using a YG(B)026D250 Electronic Fabric Strength Tester (Darong Co., China) regarding ISO 13934-1:2013. Before measurement, the wool samples were preconditioned under the standard condition (

20^{\circ} C

65 %

relative humidity) for 24 h . Testing the tensile strength of treated fabrics before conducting washing tests.
羊毛织物的拉伸强度使用 YG(B)026D250 电子织物强力测试仪 (Darong 公司，中国) 根据 ISO 13934-1:2013 进行测试。测量前，羊毛样品在标准条件下 (

20^{\circ} C

，

65 %

相对湿度) 预处理 24 小时。在进行洗涤测试之前测试处理织物的拉伸强度。

Diameter of the wool fibers was measured using an optical microscope with a

\times 400

objective lens and the coordinate ruler function built into the software (Nikon, Shanghai). To observe changes in the diameter of wool fibers, the wool fabrics were untwisted into loose fibers and then fixed on a glass slide. Observe and measure the change in diameter of the identical fiber before and after the steaming process. Measurements were taken at multiple positions on a fiber. The swelling rate was calculated according to eq 2.
羊毛纤维的直径使用配备

\times 400

物镜和软件内置坐标尺功能的光学显微镜（尼康，上海）进行测量。为观察羊毛纤维直径的变化，将羊毛织物解捻成松散纤维，然后固定在载玻片上。观察并测量相同纤维在蒸汽处理前后的直径变化。在纤维的多个位置进行测量。根据公式 2 计算膨胀率。

swelling rate (%) = \frac{D_{1} - D_{0}}{D_{1}} \times 100 %

where

D_{0}

and

D_{1}

were the diameter of the fiber before and after the steaming process, respectively.
其中

D_{0}

和

D_{1}

分别为蒸汽处理前后纤维的直径。
2.3.3. Scale Structure of the Wool Fiber. The Allwörden reaction of the fiber was performed to evaluate the effectiveness of removing the scale layer. This reaction was examined using an optical microscope (Nikon, Japan), with magnifications of

400 \times

, by immersing dried fiber samples in a saturated bromine solution for 5 min.
2.3.3. 羊毛纤维的鳞片结构。通过纤维的 Allwörden 反应来评估去除鳞片层的效果。使用光学显微镜（尼康，日本）在

400 \times

倍放大倍数下进行检测，将干燥的纤维样品浸入饱和溴溶液中 5 分钟。

The surface morphology of the wool samples was examined using a scanning electron microscope (SEM; Hitachi SU1510, Tokyo, Japan). Before imaging, the samples were mounted on a metal plate, conditioned at

20^{\circ} C

and

65 %

relative humidity ( RH ) for 24 h , and then sputtered with gold. SEM imaging was conducted at an acceleration voltage of 5 kV under ambient temperature, with magnifications of

1000 \times

and

3000 \times

.
羊毛样品的表面形貌采用扫描电子显微镜（SEM；Hitachi SU1510，日本东京）进行观察。成像前，样品被安装在金属板上，在

20^{\circ} C

和

65 %

相对湿度（ RH ）条件下调节 24 小时，然后进行金溅射。SEM 成像在环境温度下以 5 kV 的加速电压进行，放大倍数为

1000 \times

和

3000 \times

。
2.3.4. Chemical Structure and Crystallinity of the Wool Fiber. The elemental composition and spatial distribution on the surfaces of the wool samples were analyzed using an energy-dispersive spectrometer (EDS). EDS spectra of the sample surface were measured using an EX250 energy-dispersive spectrometer (Horiba, Japan) operating at a voltage of 15.0 kV .
2.3.4. 羊毛纤维的化学结构与结晶度。采用能量色散光谱仪（EDS）分析羊毛样品的元素组成和表面空间分布。使用 EX250 能量色散光谱仪（Horiba，日本）在 15.0 kV 电压下测量样品表面的 EDS 光谱。

Fourier transform infrared (FTIR) spectra were obtained using a Nicolet IS 10 infrared spectrometer (Nicolet) equipped with an attenuated total reflectance (ATR) accessory. Spectral analysis was conducted over a frequency range of 500 to

4000 {cm}^{- 1}

.
采用配备衰减全反射（ATR）附件的 Nicolet IS 10 红外光谱仪（Nicolet）获得傅里叶变换红外（FTIR）光谱。光谱分析在 500 至

4000 {cm}^{- 1}

的频率范围内进行。

The secondary structure of protein molecules in wool fibers was studied using an inVia Reflex confocal Raman microscope (Renishaw, UK). Spectral data were obtained by scanning the range of 400-2000

{cm}^{- 1}

using a laser at a wavelength of 785 nm . The crystal structure of the wool samples was analyzed utilizing a D2 PHASER X-ray diffractometer (Bruker, Germany). Scanning was performed over a range of

5 - 40^{\circ} (2 θ)

at a rate of

2^{\circ} \cdot \min^{- 1}

. The crystallinity index (C.I.) of the wool fibers was calculated using eq 3.
利用一台 inVia Reflex 共聚焦拉曼显微镜（英国 Renishaw 公司）研究了羊毛纤维中蛋白质分子的二级结构。通过使用 785 nm 波长的激光扫描 400-2000

{cm}^{- 1}

范围内的光谱数据。利用一台 D2 PHASER X 射线衍射仪（德国 Bruker 公司）分析了羊毛样品的晶体结构。扫描范围在

5 - 40^{\circ} (2 θ)

，扫描速率为

2^{\circ} \cdot \min^{- 1}

。羊毛纤维的结晶度指数（C.I.）根据公式 3 计算。

C. I. (%) = \frac{I_{9} - I_{14}}{I_{9}} \times 100 %

where

I_{9}

was the maximal intensity of crystal lattice diffraction with

2 θ

at about

9^{\circ}

, and

I_{14}

was the minimum intensity of crystal lattice diffraction with

2 θ

at about

14^{\circ}

.
其中

I_{9}

为晶体点阵衍射的最大强度，

2 θ

约为

9^{\circ}

，

I_{14}

为晶体点阵衍射的最小强度，

2 θ

约为

14^{\circ}

。

Received: May 13, 2025 接收日期：2025 年 5 月 13 日
Revised: June 18, 2025
修订日期：2025 年 6 月 18 日
Accepted: June 24, 2025
接受日期：2025 年 6 月 24 日

Degrading Natural Armor of Wool: Triple-Synergistic Scale Degradation via Limited Swelling, Disulfide Bond Reduction, and Controlled Proteolysis 降解羊毛天然护层：通过有限膨胀、二硫键还原和可控蛋白水解实现三重协同脱鳞

Abstract 摘要

1. INTRODUCTION 1. 引言

2. MATERIALS AND METHODS2. 材料与方法

Degrading Natural Armor of Wool: Triple-Synergistic Scale Degradation via Limited Swelling, Disulfide Bond Reduction, and Controlled Proteolysis
降解羊毛天然护层：通过有限膨胀、二硫键还原和可控蛋白水解实现三重协同脱鳞

2. MATERIALS AND METHODS
2. 材料与方法