Fabrication of superhydrophobic cotton fabrics by a simple chemical modification

Abstract

Hydrophobization of cotton fabrics was carried out with the use of bifunctional polysiloxanes with various contents of functional groups. Polysiloxanes contained in their structure groups capable of bonding to substrates (trialkoxysilyl or glycidyl ones) and fluoroalkyl groups showing surface activity. Two methods of surface modification were compared: (1) a one-step method via the chemical modification of fabrics with solutions of bifunctional polysiloxanes and (2) a two-step method-via preliminary modification of fabrics with silica sol followed by chemical modification with solutions of bifunctional polysiloxanes. The hydrophobicity was determined by measuring the water contact angle by drop profile tensiometry. Changes in the surface topography were examined by scanning electron microscopy. Superhydrophobic fabrics were obtained by a simple one-step method by the chemical modification in solutions of bifunctional polysiloxanes. The fabrics maintained their superhydrophobic properties even after multiple washings. The modification does not cause any changes visible to the naked eye, such as stiffening, color changes or a decrease in mechanical properties.

Fabricating durable, fluoride‐free, water repellency cotton fabrics with CPDMS

“…For example, polydimethylsiloxane (PDMS) has been widely investigated to treat cotton fabrics with desirable water repellent property, though a setback that PDMS treated fabrics offered was that they could not provide durable washing fastness due to the covalent bond of COSi between cotton and PDMS, which could be easily hydrolyzed during washing . Alternatively, many processes have been developed to fabricate durable hydrophobic cotton fabric by creating robust ether bond (COC) between water‐resistant agents and cellulose, including plasma treatment, chemical etching, and others . However, all these approaches required the use of toxic agents, complicated reaction conditions, and advanced equipment, which could seriously hinder the practical applications of environmental friendly water repellent cotton fabrics …”

“…Alternatively, many processes have been developed to fabricate durable hydrophobic cotton fabric by creating robust ether bond (COC) between water‐resistant agents and cellulose, including plasma treatment, chemical etching, and others . However, all these approaches required the use of toxic agents, complicated reaction conditions, and advanced equipment, which could seriously hinder the practical applications of environmental friendly water repellent cotton fabrics …”

“…[14][15][16][17] Alternatively, many processes have been developed to fabricate durable hydrophobic cotton fabric by creating robust ether bond (CAOAC) between water-resistant agents and cellulose, including plasma treatment, chemical etching, and others. [18][19][20][21][22] However, all these approaches required the use of toxic agents, complicated reaction conditions, and advanced equipment, which could seriously hinder the practical applications of environmental friendly water repellent cotton fabrics. [18][19][20][21][22] In this work, we present a single-step method for fabricating water repellent cotton fabric with robust water resistance and durability by using a long-chain siloxane, poly{dimethylsiloxaneco-[2-(3,4-epoxycyclohexyl)ethyl]methylsiloxane} (CPDMS).…”

“…[18][19][20][21][22] However, all these approaches required the use of toxic agents, complicated reaction conditions, and advanced equipment, which could seriously hinder the practical applications of environmental friendly water repellent cotton fabrics. [18][19][20][21][22] In this work, we present a single-step method for fabricating water repellent cotton fabric with robust water resistance and durability by using a long-chain siloxane, poly{dimethylsiloxaneco-[2-(3,4-epoxycyclohexyl)ethyl]methylsiloxane} (CPDMS). 23 The epoxide group in CPDMS could form ether bond resistant to hydrolysis, and thus is promoted to form in the finishing process.…”

Effects of Fluorine Atoms Amount and Fluorinated Acrylic Chain Length Chemically Attached to Hydroxyl Groups on the Hydrophobic Properties of Cotton Fabrics

“…However, cotton absorbs water due to its abundance of hydroxyl (-OH) groups, thus reducing its mechanical and thermoinsulation properties. Various methods have been used to obtain water repellency on cotton surfaces, such as coating with water-resistant materials like nanoparticles [1] paraffin wax [2] silicon resin [3] or fluorocarbon [4]. Coating via the chemical transformation of -OH group is the widely known method for enhancing water resistance of cotton fibers and fabrics.…”