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Supporting Information

Thermal, Waterproof, Breathable, and Antibacterial Cloth

with a Nano-Porous Structure

Qingxian Liu†, Jun Huang

†, Jianming Zhang

†, Ying Hong

†, Yongbiao Wan

†, Qi Wang

†, Mingli Gong

†, Zhigang Wu

†,‡, and Chuan Fei Guo

*,†

† Department of Materials Science & Engineering, Southern University of Science & Technology,

Shenzhen, Guangdong 518055, China

‡ State Key Laboratory of Digital Manufacturing Equipment and Technology, Huazhong University

of Science and Technology, Wuhan, 430074, China

*To whom correspondence should be addressed. Email: guocf@sustc.edu.cn

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Experimental section:

Materials. A commercially available cotton textile was used as the substrate. Hydrophobic silica

NPs with a surface area of 170 m2/g and an average primary particle diameter of 12 nm were

supplied by Evonik Industries, Germany. The ionic liquid (IL), 1-butyl-3-methylimidazolium

chloride [BMIM] Cl, was obtained from Lanzhou institute of Chemical Physics, China. Cellulose

acetate (with acetyl and hydroxy of 39.8 wt% and 3.5 wt%, respectively) was purchased from

Aladdin.

Fabrication of waterproof layer. Hydrophobic silica particles (0.3 g), PDMS precursor base (0.6 g)

and PDMS curing agent (0.03 g) were dispersed in N-hexane (20 mL). The mixture was then

ultrasonicated for 1 hour at room temperature. Next, one side of cotton cloth was coated with the

as-prepared coating solution and cured at 60 °C for 2 h.

Preparation of cellulose acetate porous film and silver network layer. Cellulose acetate was

dissolved in acetone/IL at 70 °C for 2 h to form coating solution. The concentration of cellulose

acetate in the mixed solvent was 30 mg/mL, and the volume ratio of acetone to IL was 1 to 1. Then,

the other side of cotton cloth was coated with the as-prepared coating solution, and the porous

membranes of cellulose acetate were fabricated by the immersing the cloth in a large amount of

deionized water at room temperature for 1 h. Finally, a 60 nm thick silver layer was directly

deposited on the cellulose acetate membranes by thermal evaporation.

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Characterizations.

Water Contact Angle Measurement: The water contact angle was measured via an optical video

contact angle instrument (VCA Optima XE, AST) at room temperature and was determined after a

water droplet of 2 µL placed on the sample.

Scanning Electron Microscopy (SEM): The morphology of all specimens were measured using a

scanning electron microscope (MIRA3, TESCAN).

Fourier Transform Infrared (FTIR) Spectroscopy: The infrared spectra were measured by a

using a Fourier transformation infrared spectrometer (Frontier, PerkinElmer). The transmittance

spectra were plotted by (100–(Asample/Abackground)×100)%, where Abackground was collected from an Au

foil as total reflection mirror.

Thermal Imaging: All thermal images were taken by using an infrared camera (FLIR T335). The

working distance was approximately 30 cm.

Joule Heating Measurement: The multifunctional cloth samples were cut into a 2 cm × 2 cm

dimension and placed in an airtight box. Then two adhesive foil tapes were attached on each end of

the sample for electrical contacts. The voltage was supplied using an electrochemical workstation

(CHI6601) and the sample temperature was monitored using a thermal couple (FLUKE).

Breathability Test: A total of 200 g of desiccant (98% CaSO4+ 2% CoCl2) was dried in a drying

oven at 100 °C for 2 h and then placed into a glass vial with open-top cap. Afterwards the bottle was

sealed by the cloth sample and the total mass was weighed and recorded periodically. All samples

were tested in the same period of time to avoid the deviation caused by ambient temperature and

humidity.

Bending experiment: A 2 cm × 2 cm multifunctional sample was measured under a bending

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curvature radius of ~0.5 cm for 1000 bending cycles using an Intelligent tensile tester (WS 150 100),

and meanwhile the resistance was measured using a two-probe method.

Antibiotic test: Escherichia coli were cultured for 12 hours to the stationary phase. 300 µL of

bacteria solution was spread onto each of four agar plates. Each cloth sample (1 cm × 1 cm) was

placed to the middle of the agar plate and then culture for 24 hours. Cloth with antibacterial

property would form a surrounding region on the agar plate free of bacteria.

Dry cleaning test: The multifunctional cloth was dry washed with a dry cleaning agent (Ever

Green, Down Jacket Dry Cleaner). The dry cleaner was sprayed on the surface of cloth and then

wiped. The measurement was conducted after complete volatilization of the agent.

Wear rate test: The abrasion durability of the multifunctional cloth was evaluated according to a

self-made wear tester. The tribological test was operated under a high loading of 1 MPa, a sliding

speed of 0.7 m/s, and an ambient temperature of 25 °C.

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Supplementary Figures:

Figure S1. The cross sectional SEM of a multifunctional cloth consisting of four layers: silica

NPs/PDMS, cotton textile, porous cellulose acetate film, and metallic silver film. Scale bar is 200

µm.

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Figure S2. The schematic procedure of the preparation of super-hydrophobic cotton textile. PDMS,

as an adhesive, are wrapped around silica NPs to adhere the silica NPs on the cotton fibers. The

hydrophobic silica NPs generate a dual-size surface roughness to improve the hydrophobicity of the

cloth. The low free-energy surface of PDMS and hydrophobic silica NPs are beneficial to endow

fabrics with super-hydrophobicity.

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Figure S3. Pore size and interconnectivity of cellulose acetate films can be tuned by changing

cellulose acetate concentration in solution. SEM images revealing different morphologies of the

membrane surfaces obtained from cellulose acetate concentrations of: (a) 20 mg/ml; (b) 40 mg/ml;

(c) 80 mg/ml. Scale bars are 2 µm.

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Figure S4. Textiles at different stages. (a) Normal cotton cloth. (b) Super-hydrophobic cloth (silica

NPs/Cotton). (c) After coating the cellulose acetate film (silica NPs/cotton/cellulose acetate). (d)

Multifunctional cloth (silica NPs/cotton/cellulose acetate /silver). Scale bars are 5 cm.

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Figure S5. Waterproofness testing of the textile. Water drops injected from a syringe are not able to

attach on the surface of the cloth but flow down to the desk top, indicating extraordinary

waterproofness of the textile.

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Figure S6. Cotton cloth that is dip-coated with Ag nanowires (with an average diameter about 50

nm) dispersion and vacuum dried. The mass loading of Ag nanowires was about 0.6 mg/cm2. (a) Ag

nanowires cloth. (b, c) Low (b) and high (c) magnification SEM image of Ag nanowires cloth.

Scale bars, 1 cm in panel a, 50 µm in panel b, 1 µm in panel c.

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Figure S7. Wear rate of the multifunctional cloth tested under an applied load of 1 MPa and a

sliding velocity of 0.7 m/s. Only a small increase of wear rate is observed, indicating that the cloth

is durable against mechanical wear.

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Figure S8. Time-dependent water contact angle. (a) Optical photographs of water droplets on the

cellulose acetate porous film over time. (b) Optical photographs of water droplets on silver network

over time. The water permeability of the cellulose acetate membrane and silver network should be

related to hydrophilicity of materials and high porosity of the cloth, which are significant to keep

the high breathability and perspiration of the fabric.

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Figure S9. Depositing metallic nickel on the surface of cellulose acetate porous cloth by chemical

plating. (a) Nickel network cloth. (b, c) Low (b) and high (c) magnification SEM images of nickel

network cloth. Scale bars, 1 cm in panel a, 5 µm in panel b, 1 µm in panel c.

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Figure S10. Change of resistance after several dry cleaning tests of the multifunctional cloth. Each

measurement was conducted after the cloth was dried. The resistance of the cloth shows only a

small increase after several cleaning cycles.