Linear Control of Moisture Permeability and Anti-adhesion of Bacteria

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Applications of Polymer, Composite, and Coating Materials

Linear control of moisture permeability and anti-adhesion of bacteria in a broad temperature region realized by crosslinking thermo-responsive microgels onto cotton fabrics Pan Gu, Na Fan, Yexin Wang, Jiping Wang, Peter Muller-Buschbaum, and Qi Zhong ACS Appl. Mater. Interfaces, Just Accepted Manuscript • DOI: 10.1021/acsami.9b09294 • Publication Date (Web): 29 Jul 2019 Downloaded from pubs.acs.org on July 29, 2019

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ACS Applied Materials & Interfaces

Linear Control of Moisture Permeability and Antiadhesion of Bacteria in a Broad Temperature Region Realized by Cross-Linking Thermo-Responsive Microgels onto Cotton Fabrics Pan Gu1, Na Fan1, Yexin Wang1, Jiping Wang2,*, Peter Müller-Buschbaum3,4 and Qi Zhong1,3,* 1Key

Laboratory of Advanced Textile Materials & Manufacturing Technology, Ministry of Education, Zhejiang Sci-Tech University, 310018 Hangzhou, China

2Shanghai

University of Engineering Science, 333 Long Teng Road, 201620 Shanghai, China

3Technische

Universität München, Physik-Department, Lehrstuhl für Funktionelle Materialien, James-Franck-Str. 1, 85748 Garching, Germany

4Heinz

Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Lichtenbergstr. 1, 85748 Garching, Germany

*Corresponding author. [email protected] Phone +86 571 86843436 fax +86 571 86843436 [email protected] Phone +86 571 86843665 fax +86 571 86843436 Key words: linear transition, thermo-responsive microgels, moisture permeability, comfort control, bacterial anti-adhesion 1

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Abstract Linear control of moisture permeability and anti-adhesion of bacteria in a broad temperature region are realized by cross-linking thermo-responsive microgels onto cotton fabrics. The microgels are copolymerized by monomers MEO2MA, OEGMA300 and EGMA with a molar ratio of 10:10:1. Transition temperatures of PMEO2MA and POEGMA300 are 25 oC and 60 oC, respectively. Due to the compression of already collapsed PMEO2MA to still swollen POEGMA300, the microgels present a linear shrinkage in a broad temperature region (20-70 oC). Additionally, the contact angle of the microgels stays below 60o even if the temperature is increased to 50 oC, illustrating the reserved surface hydrophilicity. The obtained microgels are cross-linked onto cotton fabrics by 1,2,3,4-butanetetracarboxylic (BTCA). The weight gain ratios (WGR) are 15% and 30%. The moisture permeability shows an excellent linear increase between 20 and 50 oC when the WGR is 30%, which is attributed to the linear shrinkage of the cross-linked microgels upon heating. As the moisture permeability is related to the fabric comfort, a linear control of comfort is obtained. In addition, the cross-linked cotton fabrics can realize 96.5% bacterial anti-adhesion at 30 oC as the surface remains hydrophilic. Based on these two unique properties, the realized cotton fabrics crosslinked with microgels are promising for application as smart textiles for wound addressing.

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Introduction The comfort of fabrics is typically related to the preservation of thermal equilibrium between the human body and the external atmosphere. Such comfort is crucial for the textiles used for daily wear. Because of its importance, comfort control has attracted more and more interest in the last decade.1-8 Recently, thermo-responsive polymers were also introduced to fabrics to realize the regulation of comfort.1,2,5,6,9-11 Due to the fact that thermo-responsive polymers can spontaneously response to the external thermal stimulus,12-15 they are very suitable for controlling comfort in fabrics. When the external temperature is below its transition temperature (TT), the thermo-responsive polymers stay in the hydrophilic and swollen state.16 Hence, the densely packed polymer layer on the fabrics can impede the heat transfer and keep the body warm. On the contrary, the increased body temperature e.g. during sports or work will switch the polymer to its hydrophobic and collapsed state. Thereby, the polymer layer turns to be porous and enhances the permeation capability of moisture from the body to the outside.9-11 As the comfort of fabrics is strongly related to the moisture permeability, it will be significantly improved as well. Among the various thermo-responsive polymers, poly(N-isopropylacrylamide), abbreviated as PNIPAM, was broadly used in fabrics to control the comfort9 as its TT (32 oC) is close to the human body temperature.13 However, PNIPAM possesses a relatively high glass transition temperature (Tg = 140 oC).13

Thus, it is in the glassy state at ambient conditions. Consequently, the

introduction of PNIPAM causes the fabrics to be stiff and unsuitable for daily wear. To overcome this drawback, recently our group introduced poly(acrylate) based thermo3



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responsive polymers into cotton fabrics to prepare smart textiles.10,11 Because their Tg values are lower than room temperature,13 the hand feel will not be influenced after cross-linking of the polymer. In addition, their TT can be easily tuned by copolymerizing the analogues with different number of ethoxy groups in the side chains.17,18 Due to the switching between hydrophilic and hydrophobic state by the external thermal stimulus, the cross-linked thermo-responsive copolymer layer can vary between a compact (below TT) and a porous (above TT) state.9-11 Consequently, the moisture permeability as well as the comfort can be regulated by the human body or by the external temperature. But commonly thermo-responsive polymers change abruptly between a hydrophobic or hydrophilic state. Thereby, the related textiles exhibit basically only a swollen and a collapsed state. Intermediate states cannot be easily realized for such systems due to the sharpness of the transition. However, in real world applications, instead of a binary switching, an automatic regulation of the moisture permeability according to the different user scenarios will be highly desirable. For instance, daily scenarios such as office work, walking, jogging and running have different requirements for moisture permeation. Thermal protection is the priority for the fabrics when humans are doing office work. While the moderate moisture permeability of fabrics is required for walking or jogging. On the contrary, the maximum permeability of the fabrics is preferred when humans are doing intensive exercises, such as running. Thus, a linear increase of the moisture permeability according to the temperature will be more suitable for textiles. Unfortunately, the fabrics with normal thermo-responsive polymers cannot fulfil these multiple demands. 4


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A novel approach will be required for the use of thermo-responsive polymers to optimize comfort control in fabrics. Nowadays, thermo-responsive nano- and microgels obtained by cross-linking of monomers were also intensively investigated.19-25 The volume of nano- and microgels experiences a dramatic shrinkage when the external temperature is above TT.19 Based on this special property, plenty of new applications can be realized by using thermoresponsive nano- and microgels instead of thermo-responsive polymers. For instance, Du et al. prepared tetra(4-pyridyl)porphyrin-functionalized PNIPAM microgels. It presents highly selectivity and sensitivity to detect Pb2+ in aqueous solution.26 With respect to fabrics, Pavla et al. cross-linked microgels from PNIPAM and chitosan copolymer (PNCS) onto cotton fabrics.27 The obtained cotton fabrics with microgels presented a significant variation of the water vapor transmission rate when increasing the temperature. However, the abrupt shrinkage of PNIPAM/PNCS microgels above TT still caused the obtained fabrics to show either a swollen or a collapsed state. Hence, a precise control of the moisture permeability by the external temperature was not realized in an optimal way, which significantly restrains the comfort regulation of fabrics. Recently, Hellweg et al. polymerized thermo-responsive core-shell microgels with a linear transition behavior by using poly(N-iso-propylmethacrylamide), (PNIPMAM, TT=44 oC) as core and poly(N-n-propylacrylamide), (PNNPAM, TT = 21 oC) as shell.28 Upon heating, first the PNNPAM shell collapsed and caused compressive forces on the still swollen PNIPMAM core. With such approach, the microgel presented a linear 5



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transition behavior between 25 oC and 41 oC. Such kind of linear transition appears to be very interesting to be applied for the control of the moisture permeability of fabrics. However, both PNIPMAM and PNNPAM possess high Tg values, which would induce the hand feel of fabrics coated with PNIPMAM and PNNPAM to be hard and uncomfortable. Moreover, the reported temperature region with a linear transition behavior was over 16 oC. Concerning real life applications, a broader transition region would be more suitable for fabrics. Besides such microgels with a core-shell structure, also other microgels resulted in a linear transition. For example, Wu et al. synthesized a novel poly(2-methoxyethyl acrylate-co-oligo(ethylene glycol) methyl ether acrylate) microgel, which exhibited a linear transition in a broader temperature range.29 This observation inspires us that microgels with a good linear transition behavior in a broad temperature region can be realized by simply tuning the molar ratio of the acrylatebased monomers with different TTs and copolymerizing them together. Comparing to their analogues with a linear chain architecture, these microgels should be able to shrink linearly upon heating. Thereby, the precise control of moisture permeability as well as comfort in fabrics will be realized. Based on this idea, di(ethylene glycol) methyl ether methacrylate (MEO2MA) and (ethylene glycol) methyl ether methacrylate (OEGMA300) are selected as the monomers for microgels in our present investigation. The TTPMEO2MA and TTPOEGMA300 are 25 oC and 60 oC, respectively.18 Moreover, their Tg values are lower than 0 oC.13 Hence, the corresponding microgels will be soft and will not influence the hand feel of cotton fabrics. In general, grafting30-33 and cross-linking9-11,34 are usually applied for the 6


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immobilization of polymers onto fabrics. Compared to the grafting, the cross-linking is simple and suitable for the mass production in industry. Besides MEO2MA and OEGMA300, ethylene glycol methacrylate (EGMA) is introduced into the microgels as well. Because both, EGMA and cotton fabrics, contain -OH groups, the immobilization of the microgels onto cotton fabrics can be realized by the cross-linker 1,2,3,4butanetetracarboxylic (BTCA). Additionally, the TTPOEGMA300 is relatively high, thereby the microgels cross-linked on cotton fabrics may stay hydrophilic when the external temperature is below TTPOEGMA300. As a hydrophilic surface is favorable for the hindrance of bacterial adhesion,9,35-38 the cotton fabrics cross-linked with P(MEO2MA-co-OEGMA300-co-EGMA) microgels will also present the capability for anti-adhesion of bacteria in a broad temperature region. Such anti-adhesion bacteria properties are in particular of interest for applications such as wound dressing.

Experimental section Materials The monomers di(ethylene glycol) methyl ether methacrylate (MEO2MA, purity 97.0%) and ethylene glycol methacrylate (EGMA, purity 95.0%) as well as the initiator ammonium persulfate (APS, purity 99.9%) were obtained from Aladdin. The monomer poly(ethylene glycol) methyl ether methacrylate (OEGMA300, average Mn=300) and cross-linker for microgels N,N-methylene bis-acrylamide (MBA, purity 99.0%) were bought from Aldrich. The cross-linker and catalyst for immobilization of microgels onto cotton fabrics were 1,2,3,4-butanetetracarboxylic acid (BTCA, purity 99.0%) and 7



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sodium hypophosphite (SHP, purity 99.0%). Both were from Aladdin as well. Before polymerization of microgels, MBA was purified by recrystallization from acetone and dried in vacuum. The other monomers and agents mentioned above were used as received. The cotton fabrics used in the investigation possesses a weight of 180 g m-2 and were cleaned by alkaline solution before use. Staphylococcus aureus (ATCC, 6538) and E. coli (E. coli, 8099) were purchased from Shanghai Ampicillin Biotechnology Co., Ltd. The Milli-Q water was from Millipore, Merck KGaA, Germany with a resistance of 18.2 MΩ cm.

Polymerization of P(MEO2MA-co-OEGMA300-co-EGMA) microgels P(MEO2MA-co-OEGMA300-co-EGMA) microgels were prepared by free radical precipitation polymerization. It was carried out in 250 mL four-necked round bottom flask, equipped with a mechanical stirrer (IKA EUROSTAR 60), a reflux condenser, a gas inlet and a feed inlet. During the polymerization, monomer MEO2MA (10 mmol; 1847 μL), OEGMA300 (10 mmol; 2866 μL), EGMA (1 mmol; 325 μL)as well as crosslinker MBA (0.6 mmol; 0.0925 g) were first dissolved in Milli-Q water (160 mL). Afterwards, the flask was purged with nitrogen for 30 min to remove the residual oxygen. Then the flask was moved into an oil bath thermo-stated at 70 oC. After heating for 60 min, 2 mL aqueous APS solution with a concentration of 0.0228 g mL-1 was added into the solution to initiate the polymerization. After reaction for 5 h at 70 oC, it was stopped by removal of solution from the oil bath and cooling at room temperature. Finally, the emulsion was purified by centrifugation (10000 rpm, 30 min) to remove 8


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the unreacted monomers and oligomers. Besides the molar ratio of MEO2MA to OEGMA300 mentioned above, the microgels with two different molar ratios of MEO2MA to OEGMA300 (1:2 and 2:1) were synthesized with the same protocol.

Preparation of cotton fabrics cross-linked with P(MEO2MA-co-OEGMA300-coEGMA) microgels To realize the immobilization of P(MEO2MA-co-OEGMA300-co-EGMA) microgels onto the cotton fabrics, cross-linker BTCA (1.5 mmol; 0.3512 g) and catalyst SHP (0.75 mmol; 0.0659 g) were added into microgels aqueous solution (120 mL). The crosslinking process was realized by a pad-dry-cure method. After immersion in the microgels solution for 10 min, the cotton fabrics were moved out and dried in the oven thermo-stated at 60 °C for 10 min. Then the temperature was increased to 130 °C. The cotton fabrics were cured at this temperature for 5 min. In order to realize different weight gain ratio, the padding time was set to 2 min or 5 min. The obtained weight gain ratios (WGRs) of the cross-linked cotton fabrics were 15% and 30%, respectively.

Dynamic light scattering (DLS) measurements The hydrodynamic diameter (DH) of P(MEO2MA-co-OEGMA300-co-EGMA) microgels were measured by DLS measurements (Malvern, Zetasizer Nano S, UK). Before the measurements, the solution was diluted 2 times and superficial dispersed 30 min at 40 Hz. After that, it was measured at 10 oC to obtain the size of the as-prepared 9



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microgels. Then the solution was heated from 10 to 70 oC with a step of 5 oC. The measurements were performed 2 min after each increase of temperature to ensure the transition of microgels to reach an equilibrium state.

Contact angle (CA) measurements The surface hydrophobicity of P(MEO2MA-co-OEGMA300-co-EGMA) microgels at different temperatures was probed by the CA measurements. Before measurements, the as-prepared microgels solution was dropped repeatedly to a clean glass slide. After drying at room temperature, a homogeneous microgels film was obtained. The attachment process of water droplet to the film surface was monitored by a drop shape analyzer (DSA-20, Krüss GmbH, Germany). 2 μL of Milli-Q water was dropped onto the microgels film thermo-stated at 20 oC. The contact angle was obtained by analyzing the shape of the droplet. After that, the temperature was gradually increased to 60 oC with a step of 10 oC. After each increase of temperature, the microgels film was first equilibrated for 20 min. Then the CA measurements were performed to obtain the correlation between the surface hydrophobicity and temperature. To minimize the measurement error, the CA at each temperature was measured three times on different positions.

Surface morphology and component measurements The morphology of microgels was obtained by SEM (ULTRA55, Carl Zeiss SMT Pte Ltd, Germany) with a magnification of 10000. The working distance and the voltage 10


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applied in the measurements were 6.4 mm and 3 kV, respectively. Before the measurement of microgels, the diluted microgels solution was dropped onto the aluminum foil to obtain a microgels film. The surface component of microgels was investigated by X-ray photoelectron spectrometer (XPS, Thermo Fisher Scientific, K-Alpha photoelectron spectroscopy). The microgels film was obtained by solution-casting microgels solution onto a PE film. The excitation source was selected as Al-Kα X-ray (1486.6 eV). The survey scans were obtained with a pass energy and step of 100 eV and 1 eV, respectively. The morphology of cotton fabrics cross-linked with microgels was measured by SEM (SU8010, HITACHI, Japan) with a magnification of 5000. The working distance and the voltage applied in the measurements were 8.9 mm and 3 kV, respectively.

Water Vapor Transmission (WVT) measurements The moisture permeability of the cotton fabrics cross-linked with P(MEO2MA-coOEGMA300-co-EGMA) microgels was measured according to the standard (GB/T 12704.2-2009). Four temperatures (20, 30, 40 and 50 °C) were selected in our measurements. Before the measurements, the moisture-permeable cup was filled with 100 mL Milli-Q water. Afterwards, the cup was covered by the cross-linked cotton fabrics. Then it was placed in the Humidity Chamber (RH = 80%, CTHI-100B, STIK Co. Ltd., Shanghai, China). After equilibrated for 1 h, the cup and the cross-linked cotton fabrics (W0) were weighted together. Then the cup was moved back to the chamber for another hour. The weight (W1) was measured again. The WVT of the 11



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cross-linked cotton fabrics was calculated by the loss of water in the cups from Equation 1.

WVT =

W0 - W1 A× t

(1)

In which A is the area of the cross-linked cotton fabrics covering the cup, t is the storage time.

Bacterial anti-adhesion measurements The capability of bacterial anti-adhesion in the cotton fabrics cross-linked with P(MEO2MA-co-OEGMA300-co-EGMA) microgels was studied as follows. The cultivation of bacterial suspensions was based on the standard (FZT 73023-2006). After that, the bacterial suspension was diluted to 108 cfu mL-1 by PBS solution and moved into a test tube containing the cross-linked cotton fabrics. The tube was then placed in a rotator thermo-stated at 30 °C, closed to the skin temperature. After rotation at 150 rpm for 18 h, the cross-linked cotton fabrics were moved out and rinsed by a sterilized PBS solution to remove the un-adhered bacteria. Then, the cotton fabrics with adhered bacteria were placed in a tube containing 5 mL of eluent. By ultrasonics for 5 min, the bacteria adhered on the fabrics were transferred into the solution. The solution obtained was diluted to a concentration of 104 cfu ML-1. 100 μL diluted bacterial solution was applied for the further bacterial cultivation. The original cotton fabrics was also measured with the same protocol to ensure the anti-adhesion capability. The antiadhesion efficiency (AE) was calculated by Equation 2.

12


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AE =

Na - Nb ×100% Na

(2)

Na and Nb represent the numbers of bacteria adhered to the original cotton fabrics and cotton fabrics cross-linked with P(MEO2MA-co-OEGMA300-co-EGMA) microgels, respectively.

Softness measurements The softness of the cotton fabrics cross-linked with P(MEO2MA-co-OEGMA300-coEGMA) microgels was measured by Phabrometer (Nu Cybertek, Inc. USA). Before measurements, the cross-linked cotton fabrics were cut into a round shape with a diameter of 11.3 cm. After that, they were mounted in a chamber with a constant temperature (T = 20 ± 2 °C) and humidity (RH = 65 ± 2%) for 24 h. Then the softness of the cotton fabrics cross-linked with P(MEO2MA-co-OEGMA300-co-EGMA) microgels was measured. The original cotton fabrics was also measured as a reference. For each sample, three identical fabrics were measured to minimize the experimental errors.

Washing fastness measurements The washing fastness measurements are performed on the cotton fabrics cross-linked with P(MEO2MA-co-OEGMA300-co-EGMA) microgels. Before the measurements, the cotton fabrics cross-linked with P(MEO2MA-co-OEGMA300-co-EGMA) microgels (1 g, 15% WGR) was placed in the beaker containing a magnetic rotator and 50 mL of detergent aqueous solution (1 g L−1). Therefore, the weight ratio of fabrics to solution 13



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was 1:50. The washing time and rotation speed were 20 min and 200 rpm, respectively. Afterward, the cotton fabrics cross-linked with P(MEO2MA-co-OEGMA300-co-EGMA) microgels were moved out and flushed with deionized water to remove the residual detergent. After dried in the oven, they were weighed again. The washing process was repeated 5 times to measure the stability of the cross-linked P(MEO2MA-coOEGMA300-co-EGMA) microgels on the cotton fabrics. To further investigate the correlation between the WGR and the stability of the cross-linked microgels, the cotton fabrics cross-linked with microgels (30% WGR) were measured as well.

Results and discussion Structure and transition behavior of as-prepared microgels The morphology of as-prepared P(MEO2MA-co-OEGMA300-co-EGMA) microgels is investigated by SEM. As seen in Figure 1, the microgels obtained present a spherical shape with a diameter of (400 ± 10) nm. Although there is no surfactant applied during the polymerization, the obtained microgels still present a homogenous shape and size. In addition, no obvious core-shell structure is observed, indicating that MEO2MA, OEGMA300 and EGMA are homogeneously copolymerized in the microgels.

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Figure 1. SEM image of P(MEO2MA-co-OEGMA300-co-EGMA) microgel solution cast on a Si substrate. Slight distortions of the spherical shape result from the preparation on the solid support.

The temperature evolution of hydrodynamic diameter DH in P(MEO2MA-coOEGMA300-co-EGMA) microgels is investigated with DLS. As presented in Figure 2, DH is (810 ± 15) nm at 10 oC, which is larger than the sizes observed in the SEM images. Typically, the hydrodynamic sizes obtained from the DLS are larger because the hydration shell is also probed with DLS. Moreover, the SEM measurement is performed at 25 oC, which is 15 oC higher than the temperature used for the DLS measurement. The higher temperature will also contribute to a shrinkage of the microgel. When the temperature gradually increases to 70 oC, DH slowly decreases to (380 ± 10) nm. Thereby, it can be concluded that P(MEO2MA-co-OEGMA300-co-EGMA) microgels show a broad transition region (20-70 oC). As indicated by the red line, a linear relationship between DH and temperature is observed between 20 and 70 oC (Figure 2). A similar linear transition behavior of thermo-responsive microgels was reported before.29 This special behavior might be related to the synergic collapse of the two thermo-responsive components. When the microgels are heated, TTPMEO2MA (25 oC) was first reached and PMEO2MA starts to collapses. However, the copolymerized POEGMA300 still stays in the swollen state and impedes the extent of collapse in PMEO2MA. Thus, instead of an abrupt transition, the microgels present a gradual shrinkage. Due to the broad transition temperature of poly(acrylate)s,39,40 the collapse of POEGMA300 sets in when the temperature is close to TTPOEGMA300 (60 oC). Thereby, 15



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a linear shrinkage of the microgels is observed.

Figure 2. Hydrodynamic diameter DH of P(MEO2MA-co-OEGMA300-co-EGMA) microgels as a function of the temperature. The temperature region (20-70 oC) in which DH shows a linear relationship to the temperature is indicated by the red line.

The temperature dependent properties, including hydrodynamic diameter (DH), dispersion index (DI) and contact angle, of the microgels with different molar ratios of monomers are compared. DH of P(MEO2MA-co-OEGMA300-co-EGMA) microgels with a molar ratio of MEO2MA to OEGMA300 (1:2) is (1015 ± 10) nm at 10 oC (red dots in Figure S1). When the molar ratios of MEO2MA to OEGMA300 are increased to 1:1 and 2:1, DH values are reduced to (810 ± 15) nm (Figure 2) and (780 ± 10) nm (black dots in Figure S1), respectively. The size of the microgels gradually decreases when the molar ratio of MEO2MA increases, due to the different molar volumes between MEO2MA and OEGMA300. As OEGMA300 possesses 5 EO groups in the side chain, its volume is much larger than that of MEO2MA, which only possesses 2 EO groups. Therefore, the microgels are enlarged when the molar ratio of OEGMA300 is increased in the microgels. Although the initial values of DH are different, the linear 16


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shrinkage behavior is still observed in the microgels with different molar ratios of MEO2MA to OEGMA300. As indicated by the red lines in Figure S1, linear shrinkages of microgels are still observed between 20 and 55 oC (MEO2MA:OEGMA300 = 2:1), 30 and 70 oC (MEO2MA:OEGMA300 = 1:2). The shift of the temperature region can be attributed to the higher TT of OEGMA300. Unlike the temperature evolution of DH, DI of the microgels does not show a prominent difference with molar ratios (Table S1). All DI values are below 0.2, indicating all these three microgels possess a narrow distribution of DH. Besides the variation of DH upon heating, the change of surface hydrophilicity with temperature is of great interest as well, as a surface hydrophilicity is favorable for the anti-adhesion of bacteria. For this reason, the contact angle of microgel films at different temperatures (20-50 oC with a step of 10 oC) is measured. As marked by the red dashed line in Figure 3, the contact angle stays below 55 o when the temperature increases up to 50 oC. Obviously, the P(MEO2MA-co-OEGMA300-co-EGMA) microgel films possess a hydrophilic surface even if the external temperature is up to 50 oC. Such property is especially beneficial for the bacterial anti-adhesion of the fabrics during daily wear. It should be noted that an increase of the contact angle is observed at 50 oC. It is caused by the thermo-responsive transition of POEGMA300 when the temperature is close to TTPOEGMA300. As no surfactant is added during the polymerization of the microgels, the hydrophilic surface is realized by the acrylate based thermo-responsive polymers in the microgels. Besides DH and DI, the temperature dependence of the contact angles is also 17



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measured in the microgels films with different molar ratios of the monomers (MEO2MA:OEGMA300 = 1:2 and 2:1). Similar as the microgels film with a molar ratio of MEO2MA to OEGMA300 (1:1), both microgels films show a contact angle less than 65o when the temperature is below 50 oC. It indicates that both microgels films are also hydrophilic and possess the capability of bacterial anti-adhesion.

Figure 3. Temperature dependence of the water contact angle on P(MEO2MA-co-OEGMA300co-EGMA) microgel films. The red dashed line is a guide to the eye.

The chemical composition of the microgels can prominently influence their properties, especially the surface components significantly affect the hydrophilicity and the antiadsorption of bacteria. For this reason, the elements on the microgels surface are analyzed by XPS. By comparing with the elements in the monomers, the chemical composition of the microgels on surface are obtained. As shown in Figure S3, peaks corresponding to C and O are observed in the XPS spectrum. The contents of C and O are (69.3 ± 0.5) % and (30.7 ± 0.5) %, respectively. Considering the amount of C and O in P(MEO2MA-co-OEGMA300-co-EGMA) microgels with their molecular formula and molar ratios, the calculated values for C and O are (68.6 ± 0.5) % and (31.4 ± 0.5) %, 18


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respectively. No prominent difference is observed between the values obtained from XPS measurement and the calculated values. Thereby, no enrichment of a certain monomer is observed on the microgels surface. The random distribution of the monomers can be attributed to the similar polymerization reactivities of MEO2MA and OEGMA300, because both have almost the same molecular structure.41,42 Similar as our previously investigated poly(acrylate) based thermo-responsive polymers,39,40,43-46 PMEO2MA possesses a relatively broad transition region. Consequently, it does not turn completely hydrophobic even the external temperature is above the TTPMEO2MA. Simultaneously POEGMA300 is hydrophilic when the temperature is below its TTPOEGMA300 (60 oC). Combining these two factors together, the microgel surface still remains hydrophilic even when the external temperature is up to 50 oC. The distribution of monomers is important for the maintenance of hydrophilicicty on surface. Because POEGMA300 possesses a higher TT than that of PMEO2MA, the enrichment of POEGMA300 on microgels surface will induce the surface to be hydrophilic even at a higher temperature. However, in our present investigation, the fabrics used for the daily wear do not require an extremely high temperature. 50 oC will be sufficient for the fabrics used in daily wear. At this temperature, POEGMA300 is still hydrophilic. Because the monomers are randomly distributed and the molar ratio of OEGMA300 to MEO2MA is 1:1, the microgels surface still remain hydrophilic at 50 oC. In our future investigation, the microgels with core (MEO2MA) - shell (OEGMA300) structure will be prepared, which will remain hydrophilic at an even broader temperature region and have an enhanced capability of 19



Page 20 of 35

bacterial anti-adhesion. Cotton fabrics cross-linked with microgels After cross-linking, the surface morphology of the original cotton fabrics and cotton fabrics cross-linked with P(MEO2MA-co-OEGMA300-co-EGMA) microgels are also probed by SEM. As seen in Figure 4a, the fibers from the original cotton fabrics show a smooth surface. No dust or polymer is visible on the fibers. In case of cotton fabrics cross-linked with P(MEO2MA-co-OEGMA300-co-EGMA) microgels (15% WGR, Figure 4b), a thick layer not only covers the fiber surface, but also fills some gaps between the fibers. It is obvious that this layer is composed of the aggerated microgels. Further increasing WGR to 30% (Figure 4c), more gaps are covered by the aggregated microgel layer. As the permeation of moisture in cotton fabrics is realized by these gaps, the collapse of the microgels upon heating can be used to control the permeability of cotton fabrics.

20


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Figure 4. SEM images of original cotton fabrics (a), cotton fabrics cross-linked with P(MEO2MA-co-OEGMA300-co-EGMA) microgels (b, 15% WGR) and (c, 30% WGR).

After the successfully cross-linking of P(MEO2MA-co-OEGMA300-co-EGMA) microgels onto the cotton fabrics, the moisture permeability is measured at different temperatures. The ratio of water vapor transmission at higher temperature to the value at 20 oC (WVTT/WVT20) in original cotton fabrics is shown in Figure 5 as the black dots. When the external temperature is set to 30 oC, WVTT/WVT20 increases to (1.3 ± 0.1). The enhanced moisture permeability of original cotton fabrics at higher 21



Page 22 of 35

temperature is caused by the increased evaporation rate for water. Further setting the external temperature to 40 oC and 50 oC, WVTT/WVT20 continues increasing to (2.0 ± 0.1) and (3.3 ± 0.1), respectively. Although WVTT/WVT20 shows an increase with temperature, no linear relationship between WVTT/WVT20 and temperature is observed.

Figure 5. The ratio of water vapor transmission at higher temperature to the value at 20 oC (WVTT/WVT20) in original cotton fabrics (black dots), cotton fabrics cross-linked with P(MEO2MA-co-OEGMA300-co-EGMA) microgels of different WGRs (15%, red and 30%, blue). The blue line is a guide to the eye.

In case of the cotton fabrics cross-linked with P(MEO2MA-co-OEGMA300-co-EGMA) microgels (15% WGR, red dots in Figure 5), the initial value of WVTT/WVT20 at 30 oC is (2.7 ± 0.1), which is 108% higher than that of the original cotton fabrics. It illustrates the moisture permeability presents a more profound change in the cross-linked cotton fabrics upon heating, which is related to the volume shrinkage of microgels at higher temperature. The microgels stay in the swollen state at 20 oC, thereby the microgels layer is densely packed. It causes WVT20 to be lower than that in the original cotton fabrics. However, the increase of external temperature causes the microgels to collapse and the microgel layer to be porous. Thus, WVT30/WVT20 significantly rises after 22


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heating. Further increasing the temperature to an even higher value causes WVTT/WVT20 to continue rising. In general, all WVTT/WVT20 values are above those of the original cotton fabrics, revealing the existence of WVT enhancement by shrinkage of the microgel. However, WVTT/WVT20 in cotton fabrics cross-linked with 15% WGR microgels does not show a linear relationship with temperature, which might be related to the incomplete coverage of cotton fabrics by the microgels. Further increasing WGR to 30%, WVTT/WVT20 (blue dots in Figure 5) at 30 oC is (3.3 ± 0.1). This value is 154% higher than the one of the original cotton fabrics, showing that an even better comfort control can be realized by increasing WGR. In addition, the temperature evolution of WVTT/WVT20 presents a linear behavior (blue line in Figure 5). Thus, the linear control of moisture permeability and comfort is achieved by the linear shrinkage of the microgels upon heating for 30% WGR. Interestingly, the gaps of WVTT/WVT20 between the original cotton fabrics and cotton fabrics cross-linked with microgel (30% WGR) is enlarged with temperatures. This special behavior reveals that the porous structure of the microgel layer is more pronounced at higher temperature, and further enhances the moisture permeability of the cross-linked cotton fabrics. The water uptake values for the original cotton fabrics and cotton fabrics cross-linked with (MEO2MA-co-OEGMA300-co-EGMA) microgels are measured in water vapor atmosphere (RH 90%) at 30 oC. From Figure S4, it is obvious that the absorption of water vapor in both fabrics possesses two stages: A dramatical increase in the first stage and a stabilization in the second stage. After exposure to water vapor for 3 h, the weight 23



Page 24 of 35

gain ratio of the original cotton fabrics and cotton fabrics cross-linked with (MEO2MAco-OEGMA300-co-EGMA) microgels are 8.53% and 11.54%, respectively. Thus, although a large amount of microgels are cross-linked on the cotton fabrics (30% WGR), the increased weight by the absorption of water vapor is not significant when compared to the original cotton fabrics.

Anti-adhesion of bacteria in cotton fabrics cross-linked with microgels Besides the comfort control, anti-adhesion of bacteria is another important issue to fabrics. The monomers used to synthesize the microgels have a side PEG chain which is hydrophilic. In the presence of water or water vapor, the PEG chains will form a tight hydration shell and have a repulsive hydration force.47 Thereby, they can prevent the adhesion of external proteins in bacteria to the surface.9 After cross-linking the microgels onto the fabrics, the cross-linked P(MEO2MA-co-OEGMA300-co-EGMA) microgels can absorb the moisture from the surrounding atmosphere and form a hydration layer on the fabric surface to inhibit adhesion of the bacteria onto the fabrics. From the results of the contact angle measurements, the microgels indeed possess a hydrophilic surface even with an external temperature of 50 °C. Because a hydrophilic surface favors the hindrance of bacterial adhesion, the anti-adhesion capability of the cross-linked cotton fabrics are investigated as well. Figures S5a and S5d represent the anti-adhesion capability of E. coli and S. aureus in the original cotton fabrics, respectively. After being cultivated at 30 oC for 18 h, a huge number of E. coli and S. aureus bacteria exist. As the number of bacteria observed 24


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is related to the ones adhered on the fabrics, the original cotton fabrics do not have the ability to impede bacterial adhesion. In case of cotton fabrics cross-linked with P(MEO2MA-co-OEGMA300-co-EGMA) microgel (15% WGR), the amounts of E. coli and S. aureus are significantly reduced (Figures S5b and S5e). As seen in Figure 6 with black columns, the anti-adhesion efficiencies (AE) for E. coil and S. aureus are (89.1 ± 0.5) % and (89.5 ± 0.5) %, respectively. Further increasing WGR to 30% (Figures S5c and S5f), AEs are up to (94.6 ± 0.5) % and (96.5 ± 0.5) % (red columns in Figure 6 for E. coil and S. aureus). It means that the cotton fabrics fully covered with cross-linked microgels possess a good anti-adhesion behavior with respect to the tested bacteria. As discussed before, the P(MEO2MA-co-OEGMA300-co-EGMA) microgels possess a hydrophilic surface even if the external temperature is up to 50 oC. For this reason, the cotton fabric cross-linked with microgels can achieve a high anti-bacterial adhesion rate at 30 oC. As the skin temperature is close to 30 oC, the cross-linked cotton fabrics can entirely prevent the bacterial adhesion during daily wear.

Figure 6. Anti-adhesion efficient (AE) of E. coli and S. aureus in cotton fabrics cross-linked with P(MEO2MA-co-OEGMA300-co-EGMA) microgels at 30 oC (15% WGR, black; 30% WGR, red). 25



Page 26 of 35

The cotton fabrics cross-linked with P(MEO2MA-co-OEGMA300-co-EGMA) microgels are able to linearly control the moisture permeability with temperature. If they are used for the wound dressing in clinic, the comfort can be significantly improved. Besides that, the hydrophilic surface can prevent the adhesion of bacteria, which lowers the chance for the infection and is beneficial for the wound recovery. Based on these special properties, the clinical applications will be of great interests in our future investigations.

Softness of cotton fabrics cross-linked with microgels For fabrics used for daily wear, the softness is crucial and should be concerned as well. Thereby, the softness of the original cotton fabrics and cotton fabrics cross-linked with different WGRs of P(MEO2MA-co-OEGMA300-co-EGMA) microgels is measured. As seen in Figure 7, the softness of the original cotton fabrics is (81.1 ± 0.5). After crosslinking microgels with WGR of 15% and 30%, the softness slightly reduced to (80.4 ± 0.5) and (80 ± 0.5), respectively. Considering the experimental errors, the cross-linked microgels do not significantly influence the softness of the cotton fabrics, which is very important for application.

26


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Figure 7. Softness of the original cotton fabrics, cotton fabrics cross-linked with P(MEO2MAco-OEGMA300-co-EGMA) microgels with WGR of 15% and 30%.

Washing fastness of the cotton fabrics cross-linked with microgels Figure 8 presents the weight loss of the cotton fabrics cross-linked with P(MEO2MAco-OEGMA300-co-EGMA) microgels (15% and 30% WGR) after washing. It is obvious that the weight shows a profound drop after the first washing. It is attributed to the removal of the physically attached microgels during washing. Afterwards, the weight loss is less and less pronounced, as the residual amount of physically attached microgels is reduced after washing. When washing for the fourth and fifth time, there is almost no change in the weight of the cross-linked cotton fabrics. After washing for 5 times, there is still 85% of microgels left on the cotton fabrics (15% WGR), indicating the cross-linked microgels are relatively stable on the cotton fabrics. Interestingly, when the WGR is increased to 30%, the residual weight is even increased to 88%. It is caused by the longer padding time during the preparation and higher cross-linked efficiency.

27



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Figure 8. The weight loss of cotton fabrics cross-linked with P(MEO2MA-co-OEGMA300-coEGMA) microgels (15% WGR, black dots and 30% WGR, red dots) as a function of washing times.

Conclusion The linear control of comfort and anti-adhesion of bacteria in a broad temperature region are realized by cross-linking P(MEO2MA-co-OEGMA300-co-EGMA) microgels onto cotton fabrics. Due to the synergic collapse of PMEO2MA and POEGMA300 upon heating, the microgels linearly shrink between 20 oC and 70 oC. In addition, the surface of microgels remains hydrophilic even if the external temperature increases up to 50 oC,

which is favorable for the anti-adhesion of bacteria. By applying the cross-linker

BTCA,

P(MEO2MA-co-OEGMA300-co-EGMA)

microgels

are

successfully

immobilized onto the cotton fabrics. The ratio of moisture permeability at higher temperature to that at 20 oC (WVTT/WVT20) presents a linear increase when the crosslinked cotton fabrics (WGR of 30%) is heated, indicating that a linear control of comfort is successfully installed in the cotton fabrics. Moreover, the anti-adhesion of bacteria reaches up to 96.5% on the cross-linked cotton fabrics when the temperature is 30 oC 28


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(close to human skin temperature). Thereby, the realized cotton fabrics cross-linked with P(MEO2MA-co-OEGMA300-co-EGMA) microgels turn out to be very interesting for use as smart textiles for wound dressing.

Supporting Information Hydrodynamic diameters (DH) of P(MEO2MA-co-OEGMA300-co-EGMA) microgels with different molar ratios as a function of the temperature are presented in Figure S1. Dispersion indexes (DI) of P(MEO2MA-co-OEGMA300-co-EGMA) microgel as a function of temperature are presented in Table 1. Temperature dependence of the water contact angle on P(MEO2MA-co-OEGMA300co-EGMA) microgel films with different molar ratios is presented in Figure S2. XPS spectrum of C and O elements on P(MEO2MA-co-OEGMA300-co-EGMA) microgels surface is presented in Figure S3. Absorption of water vapor in cotton fabrics cross-linked with P(MEO2MA-coOEGMA300-co-EGMA) microgels (30% WGR, black dots) and original cotton fabrics (red dots) as a function of the time is presented in Figure S4. Anti-adhesion of bacteria in original cotton fabrics as well as cotton fabrics cross-linked with 15% and 30% WGR of P(MEO2MA-co-OEGMA300-co-EGMA) microgels at 30 oC

is presented in Figure S5.

Acknowledgments This work is supported by the National Natural Science Foundation of China (Grant 29



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No. 51403186 and 51611130312) and National Key R&D Program of China (2017YFB0309600).

PMB

thanks

for

the

support

by

Deutsche

Forschungsgemeinschaft (DFG) via grant MU 1487/23-1.

References 1. Hu, J. L. Adaptive and Functional Polymers, Textiles and Their Applications. London, UK Imperial College Press, 2011. 2. Hu, J. L.; Meng, H.; Li, G. Q.; Ibekwe, S. I. A review of Stimuli-Responsive Polymers for Smart Textile Applications. Smart Mater. Struct. 2012, 21, 053001. 3. Ye, W. J.; Xin, J. H.; Li, P.; Lee, K. L. D.; Kwong, T. L. Durable Antibacterial Finish on Cotton Fabric by Using Chitosan-based Polymeric Core-Shell Particles. J. Appl. Polym. Sci. 2006, 102, 1787-1793. 4. Chen, S.; Yuan, L.; Li, Q.; Li, J.; Zhu, X.; Jiang, Y.; Sha, O.; Yang, X.; Xin, J. H.; Wang, J.; Stadler, F. J.; Huang, P. Durable Antibacterial and Nonfouling Cotton Textiles with Enhanced Comfort via Zwitterionic Sulfopropylbetaine Coating. Small 2016, 12, 3516. 5. Wang, X. W.; Hu, H. W.; Yang, Z. Y.; He, L.; Kong, Y. Y.; Fei, B.; Xin. J. H. Smart Hydrogel-Functionalized Textile System with Moisture Management Property for Skin Application. Smart Mater. Struct. 2014, 23, 125027-125036. 6. Lv, H. N.; Xue, Y.; Cai, Z. S.; Sun, J. Microporous Membrane with TemperatureSensitive Breathability based on PU/PNIPAAm Semi-IPN. J. Appl. Polym. Sci. 2012, 124, E2-E8. 7. Holme, I. Innovative Technologies for High Performance Textiles. Color Technol. 2007, 123, 59-73. 8. Save, N. S.; Jassal, M.; Agrawal, A. K. Smart Breathable Fabric. J. Ind. Text. 2005, 34, 139-155. 9. Wang, J. P.; Chen, Y.; An, J.; Xu, K.; Chen, T.; Müller-Buschbaum, P.; Zhong, Q. Intelligent Textiles with Comfort Regulation and Inhibition of Bacterial Adhesion Realized

by

Cross-Linking

Poly(n-isopropyl

acrylamide-co-ethylene

glycol

methacrylate) to Cotton Fabrics. ACS Appl. Mater. Inter. 2017, 9, 13647-13656. 10. Chen, Y. Y.; An, J.; Zhong, Q.; Müller-Buschbaum, P.; Wang, J. P. Smart Control 30


Page 31 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


of Cotton Fabric Comfort by Cross-linking Thermo-responsive Poly(2-(2methoxyethoxy) ethoxyethyl methacrylate-co-ethylene glycol methacrylate). Text. Res. J. 2017, 87, 1620-1630. 11. Zhong, Q.; Lu, M.; Nieuwenhuis, S.; Wu, B. S.; Wu, G. P.; Xu, Z. K.; MüllerBuschbaum, P.; Wang, J. P. Enhanced Stain Removal and Comfort Control Achieved by Cross-Linking Light and Thermo Dual-Responsive Copolymer onto Cotton Fabrics. ACS Appl. Mater. Inter. 2019, 11, 5414-5426. 12. Theato, P.; Sumerlin, B. S.; OReilly, R. K.; Epps, III, T. H. Stimuli Responsive Materials. Chem. Soc. Rev. 2013, 42, 7055-7056. 13. Aseyev, V.; Tenhu, H.; Winnik, F. M. Non-Ionic Thermoresponsive Polymers in Water. Adv. Polym. Sci. 2011, 242, 29-89. 14. Vancoillie, G.; Frank, D.; Hoogenboom, R. Thermoresponsive Poly(oligo ethylene glycol acrylates). Prog. Poly. Sci. 2014, 39, 1074-1095. 15. Sun, W.; An, Z.; Wu, P. Y. UCST or LCST? Composition-Dependent Thermoresponsive Behavior of Poly(N-acryloylglycinamide-co-diacetone acrylamide). Macromolecules 2017, 50, 2175-2182. 16. Fullbrandt, M.; Ermilova, E.; Asadujjaman, A.; Holzel, R.; Bier, F. F.; von Klitzing, R.; Schonhals, A. Dynamics of Linear Poly(N-isopropylacrylamide) in Water around the Phase Transition Investigated by Dielectric Relaxation Spectroscopy. J. Phys. Chem. B 2014, 118, 3750-3759. 17. Lutz, J. F.; Akdemir, O.; Hoth, A. Point by Point Comparison of Two Thermosensitive Polymers Exhibiting a Similar LCST: Is the Age of Poly(NIPAM) over? J. Am. Chem. Soc. 2006, 128, 13046-13047. 18. Lutz, J. F.; Hoth, A. Preparation of Ideal PEG Analogues with a Tunable Thermosensitivity

by

Controlled

Radical

Copolymerization

of

2-(2-

methoxyethoxy)ethyl Methacrylate and Oligo(ethylene glycol) Methacrylate. Macromolecules 2006, 39, 893-896. 19. Lyon, L. A.; Meng, Z.; Singh, N.; Sorrell, C. D.; John, A. S. Thermoresponsive Microgel-Based Materials. Chem. Soc. Rev. 2009, 38, 865-874. 20. Plamper, F. A.; Richtering W. Functional Microgels and Microgel Systems. Accounts Chem. Res. 2017, 50, 131-140. 21. Xue, J. Q.; Bai, W.; Duan, H. Y.; Nie, J. J.; Du, B. Y.; Sun, J. Z.; Tang, B. Z. Tetraphenylethene Cross-Linked Thermosensitive Microgels via Acylhydrazone Bonds: Aggregation-Induced Emission in Nanoconfined Environments and the 31



Page 32 of 35

Cononsolvency Effect. Macromolecules 2018, 51, 5762-5772. 22. Wu, Q. W.; Lv, C.; Zhang, Z. J.; Li, Y. Q.; Nie, J. J.; Xu, J. T.; Du, B. Y. Poly(Nisopropylacrylamide-co-1-vinyl-3-alkylimidazolium bromide) Microgels with Internal Nanophase-Separated Structures. Langmuir 2018, 34, 9203-9214. 23. Uhlig, K.; Wegener, T.; He, J.; Zeiser, M.; Bookhold, J.; Dewald, I.; Godino, N.; Jaeger, M.; Hellweg, T.; Fery, A.; Duschl, C. Patterned Thermoresponsive Microgel Coatings for Noninvasive Processing of Adherent Cells. Biomacromolecules 2016, 17, 1110-1116. 24. Nessen, K. V.; Karg, M.; Hellweg, T. Thermoresponsive poly-(Nisopropylmethacrylamide) Microgels: Tailoring Particle Size by Interfacial Tension Control. Polymer 2013, 54, 5499-5510. 25. Zhao, Y.; Zheng, C.; Wang, Q.; Fang, J.; Zhou, G.; Zhao, H.; Yang, Y.; Xu, H.; Feng, G.; Yang, X. Permanent and Peripheral Embolization: Temperature-Sensitive P(N-isopropylacrylamide-co-butyl Methylacrylate) Nanogel as a Novel Blood Vessel Embolic Material in the Interventional Therapy of Liver Tumors. Adv. Funct. Mater. 2011, 21, 2035-2042. 26. Wen, B.; Xue, J. Q.; Zhou, X. J.; Wu, Q. W.; Nie, J. J.; Xu, J. T.; Du, B. Y. Highly Selective and Sensitive Detection of Pb2+ in Aqueous Solution Using Tetra(4pyridyl)porphyrin-Functionalized Thermosensitive Ionic Microgels. ACS Appl. Mater. Inter. 2018, 10, 25706-25716. 27. Lavric, P. K.; Tomsic, B.; Simoncic, B.; Warmoeskerken, M. M. C. G.; Jocic. D. Functionalization of Cotton with Poly-NiPAAm/chitosan microgel: Part II. StimuliResponsive Liquid Management Properties. Cellulose 2012, 19, 273–287. 28. Zeiser, M.; Freudensprung, I.; Hellweg, T., Linearly Thermoresponsive core-shell Microgels: Towards a New Class of Nanoactuators. Polymer 2012, 53, 6096-6101. 29. Hou, L.; Wu, P. Microgels with Linear Thermosensitivity in a Wide Temperature Range. Macromolecules 2016, 49, 6095-6100. 30. Sun, Y.; Sun, G. Durable and Regenerable Antimicrobial Textile Materials Prepared by a Continuous Grafting Process. J. Appl. Polym. Sci. 2002, 84, 1592-1599. 31. Liu, Y. Q.; Hu, J. L.; Zhu, Y.; Yang, Z. H. Surface Modification of Cotton Fabric by Grafting of Polyurethane. Carbohyd. Polym. 2005, 61, 276-280. 32. Yang, H. R.; Esteves, A. C. C.; Zhu, H. J.; Wang, D. J.; Xin, J. H. In-Situ Study of the Structure and Dynamics of Thermo-Responsive PNIPAAm Grafted on a Cotton Fabric. Polymer 2012, 53, 3577-3586. 32


Page 33 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


33. Sun, J.; Yao, L.; Gao, Z. Q.; Peng, S. J.; Wang, C. X.; Qiu, Y. P. Surface Modification of PET Films by Atmospheric Pressure Plasma-Induced Acrylic Acid Inverse Emulsion Graft Polymerization. Surf. Coat. Tech. 2010, 204, 4101-4106. 34. Yang, Z. H.; Hu, J. L.; Liu, Y. Q.; Yeung, L. The Study of Crosslinked Shape Memory Polyurethanes. Mater. Chem. Phys. 2006, 98, 368-372. 35. Lichter, J. A.; Van, K. J.; Rubner, M. F. Design of Antibacterial Surfaces and Interfaces: Polyelectrolyte Multilayers as a Multifunctional Platform. Macromolecules 2009, 42, 8573-8586. 36. Banerjee, I.; Pangule, R. C.; Kane, R. S. Antifouling Coatings: Recent Developments in the Design of Surfaces that Prevent Fouling by Proteins, Bacteria, and Marine Organisms. Adv. Mater. 2011, 23, 690-718. 37. Cloutier, M.; Mantovani, D.; Rosei, F. Antibacterial Coatings: Challenges, Perspectives, and Opportunities. Trends Biotechnol. 2015, 33, 637-652. 38. Cheng, C.; He, A.; Nie, C. X.; Xia, Y.; He, C.; Ma, L.; Zhao, C. S. One-Pot CrossLinked Copolymerization for the Construction of Robust Antifouling and Antibacterial Composite Membranes. J. Mater. Chem. B 2015, 3, 4170-4180. 39. Zhong, Q.; Wang, W. N.; Adelsberger, J.; Golosova, A.; Bivigou Koumba, A. M.; Laschewsky, A.; Funari, S. S.; Perlich, J.; Roth, S. V.; Papadakis C. M.; MüllerBuschbaum P. Collapse Transition in Thin Films of Poly(methoxydiethylenglycol acrylate), Colloid Polym. Sci. 2011, 289, 569-581. 40. Zhong, Q.; Metwalli, E.; Rawolle, M.; Kaune, G.; Bivigou-Koumba, A. M.; Laschewsky, A.; Papadakis, C. M.; Cubitt, R.; Müller-Buschbaum, P. Structure and Thermal

Response

of

Thin

Thermoresponsive

Polystyrene-block-

poly(methoxydiethylene glycol acrylate)-block-polystyrene Films, Macromolecules 2013, 46, 4069-4080. 41. Roos, S. G.; Müller, A. H. E.; Matyjaszewski, K. Copolymerization of n-Butyl Acrylate with Methyl Methacrylate and PMMA Macromonomers by Conventional and Atom Transfer Radical Copolymerization. ACS Symp. Ser. 2000, 768, 361-371. 42. Lutz, J. F.; Jahed, N.; Matyjaszewski, K. Preparation and Characterization of Graft Terpolymers with Controlled Molecular Structure. J. Polym. Sci. A: Polym. Chem. 2004, 42, 1939-1952. 43. Nieuwenhuis, S.; Zhong, Q.; Metwalli, E.; Bießmann, L.; Philipp, M.; Miasnikova, A.; Laschewsky, A.; Papadakis, C. M.; Cubitt, R.; Wang, J. P.; Müller-Buschbaum, P. Hydration and Dehydration Kinetics: Comparison between Poly(N‑isopropyl 33



Page 34 of 35

methacrylamide) and Poly(methoxy diethylene glycol acrylate) Films. Langmuir 2019, 35, 7691-7702. 44. Zhong, Q.; Mi, L.; Metwalli, E.; Bießmann, L.; Philipp, M.; Miasnikova, A.; Laschewsky, A.; Papadakis, C. M.; Cubitt, R.; Schwartzkopf, M.; Roth, S. V.; Wang, J. P.; Müller-Buschbaum; P. Effect of Chain Architecture on the Swelling and Thermal Response of Star-Shaped Thermo-Responsive (Poly(methoxy diethylene glycol acrylate)-block-polystyrene)3 Block Copolymer Films. Soft Matter 2018, 14, 65826594. 45. Zhong, Q.; Metwalli, E.; Rawolle, M.; Kaune, G.; Bivigou-Koumba, A. M.; Laschewsky, A.; Papadakis, C. M.; Cubitt, R.; Wang, J. P.; Müller-Buschbaum, P. Influence of Hydrophobic Polystyrene Blocks on the Rehydration of Polystyrene-block-poly(methoxy diethylene glycol acrylate)-block-polystyrene Films Investigated by in Situ Neutron Reflectivity. Macromolecules 2016, 49, 317-326. 46. Zhong, Q.; Metwalli, E.; Rawolle, M.; Kaune, G.; Bivigou-Koumba, A. M.; Laschewsky, A.; Papadakis, C. M.; Cubitt, R.; Müller-Buschbaum, P. Rehydration acrylate)

of

Films

Thermoresponsive Probed

in

Situ

Poly(monomethoxydiethylene by

Real-Time

Neutron

glycol

Reflectivity.

Macromolecules 2015, 48, 3604-3612. 47. Chen, W. Y.; Hsu, M. Y.; Tsai, C. W.; Chang, Y.; Ruaan, R. C.; Kao, W. H.; Huang, E. W.; Chuan, H. C. Kosmotrope-like Hydration Behavior of Polyethylene Glycol from Microcalorimetry and Binding Isotherm Measurements. Langmuir 2013, 29, 42594265.

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TOC graph Linear Control of Moisture Permeability and Anti-adhesion of Bacteria in a Broad Temperature Region Realized by Cross-Linking Thermo-Responsive Microgels onto Cotton Fabrics

Pan Gu, Na Fan, Yexin Wang, Jiping Wang, Peter Müller-Buschbaum and Qi Zhong

35


Linear Control of Moisture Permeability and Anti-adhesion of Bacteria

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