Tong Lin

Publications (79)206.14 Total impact

• Source

  Available from: deakin.edu.au

  Article: Effects of polymer concentration and cationic surfactant on the morphology of electrospun polyacrylonitrile nanofibres

  Tong Lin, Hongxia Wang, Huimin Wang, Xungai Wangt
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  ABSTRACT: tralia [ Manuscript received January 24, 2005] PAN nanofibres were prepared via an electrospinning process. The effect of polymer concentration on the fibre morphology was studied. At a very dilute solution, no fibres were obtained in the electrospinning process. As the concentration increased, the fibre morphology evolved from a beads-on-string structure to a uniform fibre structure with increasing fibre diameters. However, when the same electrospinning process was conducted with the addition of a cationic surfactant, the formation of disconnected beads was prevented, and the number of beads-on-string structures reduced significantly. In addition, the presence of cationic surfactant reduced the average diameter of the electrospun PAN nanofibres.
  J. Mater. Sci. Techno!. ; 1.
• Article: Elastin and collagen enhances electrospun aligned polyurethane as scaffolds for vascular graft.

  Cynthia S Wong, Xin Liu, Zhiguang Xu, Tong Lin, Xungai Wang
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  ABSTRACT: Mismatch in mechanical properties between synthetic vascular graft and arteries contribute to graft failure. The viscoelastic properties of arteries are conferred by elastin and collagen. In this study, the mechanical properties and cellular interactions of aligned nanofibrous polyurethane (PU) scaffolds blended with elastin, collagen or a mixture of both proteins were examined. Elastin softened PU to a peak stress and strain of 7.86 MPa and 112.28 % respectively, which are similar to those observed in blood vessels. Collagen-blended PU increased in peak stress to 28.14 MPa. The growth of smooth muscle cells (SMCs) on both collagen-blended and elastin/collagen-blended scaffold increased by 283 and 224 % respectively when compared to PU. Smooth muscle myosin staining indicated that the cells are contractile SMCs which are favored in vascular tissue engineering. Elastin and collagen are beneficial for creating compliant synthetic vascular grafts as elastin provided the necessary viscoelastic properties while collagen enhanced the cellular interactions.
  Journal of Materials Science Materials in Medicine 04/2013; · 2.32 Impact Factor
• Article: Unidirectional water transfer effect from fabrics having a superhydrophobic-to-hydrophilic gradient.

  Hongxia Wang, Xungai Wang, Tong Lin
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  ABSTRACT: In this study, we demonstrate that fabrics having a wettability gradient from superhydrophobic to hydrophilic through the thickness direction show a novel directional water transfer effect: water can transfer from the superhydrophobic to the hydrophilic side, but not in the opposite direction unless an external force is applied. A sol-gel technology was used to prepare a nano-structured superhydrophobic coating on fabrics, and the coated fabrics showed water contact-angle as high as 165 degrees. When the coated fabric was subjected to a photochemistry treatment from one fabric side, the irradiated surface turned hydrophilic permanently, while the back side still maintained the superhydrophobicity. The treated fabric can transfer water droplet rapidly from hydrophobic to hydrophilic side, and the pressure allowing water breakthrough the fabric are different considerably between the two fabric sides. The directional water transfer effect is affected by the wettability gradient. Such a directional water transfer coating may be useful to develop new functional fabrics for defence applications.
  Journal of Nanoscience and Nanotechnology 02/2013; 13(2):839-42. · 1.56 Impact Factor
• Article: Apatite-coated three-dimensional fibrous scaffolds and their osteoblast response.

  Yanwei Tang, Yan Zhao, Cynthia S Wong, Xungai Wang, Tong Lin
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  ABSTRACT: Apatite was applied onto the fiber surface of an interbonded three-dimensional polycaprolactone fibrous scaffold through a vacuum nitrogen plasma pretreatment followed by immersion in a simulated body fluid. The plasma pretreatment improved the wettability and accelerated apatite deposition on the fiber surface. The apatite coating was proven to be biocompatible to fibroblast cells without any cytotoxicity. Two osteoblast cell lines, human fetal osteoblast cells (hFOB1.19) and human osteosarcoma cells (Saos-2), were used for evaluating the cell response of the fibrous matrices. The apatite coating showed enhanced cell attachment for both hFOB1.19 and Saos-2 cells. In comparison to the uncoated fibrous scaffolds, the apatite-coated fibrous matrix had an improved hFOB1.19 cell proliferation for at least 2 weeks. Enhanced cell differentiation was also observed on the apatite-coated fibrous matrix primarily on the third, 10th, and 14th days of culture. Saos-2 cells showed improved proliferation in the apatite-coated matrix mainly on days 3 and 14, but the differentiation was increased only on the third day of culture. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.
  Journal of Biomedical Materials Research Part A 08/2012; · 2.63 Impact Factor
• Article: Disc-electrospun cellulose acetate butyrate nanofibers show enhanced cellular growth performances.

  Chen Huang, Haitao Niu, Chunchen Wu, Qinfei Ke, Xiumei Mo, Tong Lin
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  ABSTRACT: Cellulose acetate butyrate nanofibers were prepared separately by two electrospinning techniques; a needleless electrospinning using a disc as spinneret and a rotary drum as collector and a conventional needle electrospinning using a rotary drum as collector. Compared to the needle-electrospun nanofibers, the disc-electrospun nanofibers were coarser with a wider diameter distribution. Both fibers had a similar surface morphology and they showed no difference in chemical components, but the disc-electrospun nanofibers were slightly higher in crystallinity. The productivity of disc electrospinning was 150 times larger than that of needle electrospinning. The disc-electrospun nanofiber mats were found to have a three dimensional fibrous structure with an average pore size of 9.1 μm, while the needle-electrospun nanofibers looked more like a two-dimensional sheet with a much smaller average pore size (3.2 μm). Fibroblasts and Schwann cells were cultured on the fibrous matrices to assess the biocompatibility. The disc-electrospun nanofiber webs showed enhanced cellular growth for both fibroblasts and Schwann cells, especially in a long culture period. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2012.
  Journal of Biomedical Materials Research Part A 07/2012; · 2.63 Impact Factor
• Article: Needleless electrospinning: influences of fibre generator geometry

  Haitao Niu, Xungai Wang, Tong Lin
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  ABSTRACT: The fibre generator shape and dimension are key factors affecting the needleless electrospinning process and fibre fineness. In this work, cylinder with rounded rim, disc and ball were used as spinnerets to electrospin polyvinyl alcohol and polyacrylonitrile solutions. A finite element method was used to analyse how the spinneret geometry affected the electric field generated during electrospinning and the associated changes in fibre diameter and productivity. For cylinder spinnerets, increasing the rim radius reduced the discrepancy of electric field intensity between the cylinder end and middle area, which affected the fibre productivity. The electrospinning failed to operate when the rim radius was over 20 mm. With decreasing cylinder diameter, the electric field intensity in the middle area increased, improving the fibre productivity. Thinner disc spinnerets increased the electric field intensity, resulting in finer nanofibres and higher productivities. Ball spinnerets produced evenly distributed electric field, but failed to electrospin fibres when the diameters were below 60 mm. It has been found that strong and narrowly distributed electric field in the fibre-generating area can significantly facilitate the mass production of quality nanofibres.
  The Journal of The Textile Institute. 07/2012; 103(7):787-794.
• Article: Antimicrobial electrospun nanofibers of cellulose acetate and polyester urethane composite for wound dressing.

  Xin Liu, Tong Lin, Yuan Gao, Zhiguang Xu, Chen Huang, Gang Yao, Linlin Jiang, Yanwei Tang, Xungai Wang
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  ABSTRACT: In this study, a series of nanofibrous membranes were prepared from cellulose acetate (CA) and polyester urethane (PEU) using coelectrospinning or blend-electrospinning. The drug release, in vitro antimicrobial activity and in vivo wound healing performance of the nanofiber membranes were evaluated for use as wound dressings. To prevent common clinical infections, an antimicrobial agent, polyhexamethylene biguanide (PHMB) was incorporated into the electrospun fibers. The presence of CA in the nanofiber membrane improved its hydrophilicity and permeability to air and moisture. CA fibers became slightly swollen upon contacting with liquid phase. CA not only increased the liquid uptake but also created a moist environment for the wound, which accelerated wound recovery. PHMB release dynamics of the membranes was controlled by the structure and component ratios of the membranes. The lower ratio of CA: PEU helped to preserve the physical and thermal properties of the membranes, and also reduced the burst release effectively and slowed down diffusion of PHMB during in vitro tests. The controlled-diffusion membranes exerted long-term antimicrobial effect for wound healing.
  Journal of Biomedical Materials Research Part B Applied Biomaterials 06/2012; 100(6):1556-65. · 2.15 Impact Factor
• Article: Biofunctionalization of 3D Nylon 6,6 Scaffolds Using a Two-Step Surface Modification.

  Edin Nuhiji, Cynthia S Wong, Alessandra Sutti, Tong Lin, Mark Kirkland, Xungai Wang
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  ABSTRACT: Nylon is a relatively inert polymer. The ability to easily functionalize nylon with biomolecules will improve the utilization of nylon in biological systems. A potential use of the biofunctionalized nylon scaffolds is in devices for cell therapeutics that can specifically select cells present in small numbers, such as hematopoietic stem cells. This study developed a versatile and simple two-step technique combining oxygen plasma treatment with wet silanization to graft biomolecules onto nylon 6,6 3D porous scaffolds. Scaffolds that were exposed to oxygen plasma exhibited up to 13-fold increase in silane attachment ((3-mercaptopropyl)trimethoxysilane/(3-aminopropyl)trimethoxysilane) compared to untreated scaffolds. To address the limitation of nondestructive characterization of the surface chemistry of 3D scaffolds, fluorescent CdSe/ZnS nanoparticles were used as a reporting tool for -NH(2) functionalized surfaces. Scaffolds that were covalently bound with neutravidin protein remained stable in phosphate buffered saline up to four months. Functionality of the neutravidin-grafted scaffolds was demonstrated by the specific binding of CD4 cells to the scaffold via CD4-specific antibody. Ultimately, these neutravidin-functionalized 3D nylon scaffolds could be easily customized on demand utilizing a plethora of biotinylated biomolecules (antibodies, enzymes and proteins) to select for specific cell of interest. This technique can be extended to other applications, including the enhancement of cell-scaffold interactions.
  ACS Applied Materials & Interfaces 06/2012; · 4.53 Impact Factor
• Article: Effects of ultrasonic treatment on wool fibre and fabric properties

  Qing Li, Tong Lin, Xungai Wang
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  ABSTRACT: The protein structures of wool, treated in fabric form with ultrasonics for different time durations, were analysed by X-ray diffraction (XRD) and Fourier transform infrared (FTIR), in comparison with the wool without ultrasonic treatment. Fabric water absorption and tensile properties were measured in addition to the fibre micro-structure analysis. It is shown that while the ultrasonic treatment had little effect on the fibre crystallinity, some chemical structures in the protein were altered to some extent during the process. Disruption of fibre internal waxy lipids upon ultrasonic treatment provided the fibres with increased water absorption. Protein chains in the macro fibrils were shown to be rearranged to a more regular and less flexible structure, as a result of the ultrasonic treatment. Fabric tensile tests showed an increased tenacity and a reduced extensibility to the ultrasonically treated fabric. Prolonged ultrasonic treatment, however, significantly reduced both fabric tenacity and extensibility.
  The Journal of the Textile Institute. 06/2012; 103(6):662-668.
• Article: Layer-by-layer assembly of antibacterial coating on interbonded 3D fibrous scaffolds and its cytocompatibility assessment.

  Yanwei Tang, Yan Zhao, Hongxia Wang, Yuan Gao, Xin Liu, Xungai Wang, Tong Lin
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  ABSTRACT: Bonded fibrous matrices have shown great potential in tissue engineering because of their unique 3D structures and pore characteristics. For some applications, bacterial infections must be taken into account, and antibacterial function is highly desired. In this study, an antibacterial polymer, polyhexamethylene biguanide (PHMB), was applied onto the fiber surface of a bonded poly(ε-caprolactone) (PCL) fibrous matrix with the objective to achieve both strong antibacterial effect and good cell compatibility. The coatings were prepared by using an electrostatic layer-by-layer (LbL) assembly technique, which allowed the control of PHMB loading and coating uniformity on the fiber surface. The PHMB coating provided antibacterial activities, but had no toxicity on mammalian cells. This bonded PCL fibrous matrix with electrostatically self-assembled PHMB may provide a new antiinfective tissue scaffold for various biomedical applications.
  Journal of Biomedical Materials Research Part A 05/2012; 100(8):2071-8. · 2.63 Impact Factor
• Article: Photochromic fabrics with improved durability and photochromic performance

  Tong Cheng, Tong Lin, Rex Brady, Xungai Wang
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  ABSTRACT: Previously, we have reported a method for producing photochromic wool fabric by applying a thin layer of hybrid silica-photochromic dye onto the wool surface. While the photochromic coating showed a very fast optical response and had little influence on the fabric handle, its durability was poor. In this study, the durability of the photochromic coating layer was improved by introducing epoxy groups into the silica matrix via co-hydrolysis and co-condensation of an alkyl trialkoxysilane compound (ATAS) and 3-glycidoxypropyltrimethoxysilane (GPTMS). The presence of epoxy groups in the silica enhanced both washing and abrasion durability or fastness. In addition, the optical response speed was slightly increased as well. Effects of the type of alkyl silane and the GPTMS/alkyl silane ratio on the coating durability, fabric handle and optical response were examined.
  Fibers and Polymers 04/2012; 9(5):521-526. · 0.84 Impact Factor
• Article: Synthesis and photophysical properties of linear and hyperbranched conjugated polymer

  Qingguo He, Tong Lin, Fenglian Bai
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  ABSTRACT: A novel light-emitting alternating copolymer, known as hyperbranched conjugated polymer (HPV), has been designed and synthesized by Wittig reaction, and so have its linear counterparts, including MPV and PPV. FTIR,1H NMR,13C NMR and GPC were combined to characterize these polymers. Their photophysical properties were investigated both in solution and in solid film. Interestingly, almost the same maxima of absorption and emission wavelengths were observed for the solution of HPV and MPV in CH2Cl2 respectively, located at the shorter wavelength region related to PPV. In addition, the absorption peak of HPV film blue shifted while its emission peak red shifted as MPV compared with the case of its CH2Cl2 solution. However, both the absorption and emission spectra of the PPV film showed red shift, which resulted from a special electronic structure. Keywordshyperbranched conjugated polymer-linear conjugated polymer-photophysical properties-electronic structure
  Chinese Science Bulletin 04/2012; 46(8):636-641. · 1.32 Impact Factor
• Article: Applications of electrospun nanofibers

  Jian Fang, HaiTao Niu, Tong Lin, XunGai Wang
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  ABSTRACT: Polymeric nanofiber non-woven materials produced by electrospinning have extremely high surface-to-mass (or volume) ratio and a porous structure with excellent pore-interconnectivity. These characteristics plus the functionalities and surface chemistry of the polymer itself impart the nanofibers with desirable properties for a range of advanced applications. This review summarizes the recent progress in electrospun nanofibers, with an emphasis on their applications.
  Chinese Science Bulletin 04/2012; 53(15):2265-2286. · 1.32 Impact Factor
• Article: Fluoroalkyl silane modified silicone rubber/nanoparticle composite: a super durable, robust superhydrophobic fabric coating.

  Hua Zhou, Hongxia Wang, Haitao Niu, Adrian Gestos, Xungai Wang, Tong Lin
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  ABSTRACT: A superhydrophobic fabric coating made of a crosslinked polydimethylsiloxane elastomer, containing well-dispersed hydrophobic silica nanoparticles and fluorinated alkyl silane, shows remarkable durability against repeated machine washes, severe abrasion, strong acid or base, boiling water or beverages and excellent stain resistance.
  Advanced Materials 04/2012; 24(18):2409-12. · 13.88 Impact Factor
• Article: Photoreactive azido-containing silica nanoparticle/polycation multilayers: durable superhydrophobic coating on cotton fabrics.

  Yan Zhao, Zhiguang Xu, Xungai Wang, Tong Lin
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  ABSTRACT: In this study, we report the functionalization of silica nanoparticles with highly photoreactive phenyl azido groups and their utility as a negatively charged building block for layer-by-layer (LbL) electrostatic assembly to produce a stable silica nanoparticle coating. Azido-terminated silica nanoparticles were prepared by the functionalization of bare silica nanoparticles with 3-aminopropyltrimethoxysilane followed by the reaction with 4-azidobenzoic acid. The azido functionalization was confirmed by FTIR and XPS. Poly(allylamine hydrochloride) was also grafted with phenyl azido groups and used as photoreactive polycations for LbL assembly. For the photoreactive silica nanoparticle/polycation multilayers, UV irradiation can induce the covalent cross-linking within the multilayers as well as the anchoring of the multilayer film onto the organic substrate, through azido photochemical reactions including C-H insertion/abstraction reactions with surrounding molecules and dimerization of azido groups. Our results show that the stability of the silica nanoparticle/polycation multilayer film was greatly improved after UV irradiation. Combined with a fluoroalkylsilane post-treatment, the photoreactive LbL multilayers were used as a coating for superhydrophobic modification of cotton fabrics. Herein the LbL assembly method enables us to tailor the number of the coated silica nanoparticles through the assembly cycles. The superhydrophobicity of cotton fabrics was durable against acids, bases, and organic solvents, as well as repeated machine wash. Because of the unique azido photochemistry, the approach used here to anchor silica nanoparticles is applicable to almost any organic substrate.
  Langmuir 04/2012; 28(15):6328-35. · 4.19 Impact Factor
• Article: Thermo-responsive Hercosett/Poly(N-isopropylacrylamide) films: a new, fast, optically responsive coating.

  Jing Wang, Alessandra Sutti, Xungai Wang, Tong Lin
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  ABSTRACT: Poly(N-isopropylacrylamide) (PNIPAM) is a common thermo-responsive, water-soluble polymer, while Hercosett is a cationic resin commonly employed in the paper industry. In this paper, Hercosett™ and poly(N-isopropylacrylamide) (PNIPAM) nanoparticles were used to prepare composite films that show thermo-responsive behavior and swelling-shrinking properties in water. First, size-controlled PNIPAM hydrogel nanoparticles were synthesized. These were then embedded within a matrix of the cationic resin Kymene 577H by film casting. The distribution of nanoparticles in the resin film was investigated. The thermo-responsive properties of the as-synthesized PNIPAM hydrogel nanoparticles and of the composite films were characterized together with the repeatability of the swelling-shrinking cycles. The presence of nanoparticles endowed the film with highly enhanced water retention (in comparison with resin-only films) and, most importantly, thermo-responsiveness. A very fast optical and morphological response was in fact observed. Due to the dual (optical and morphological) response, this new system is suitable for applications in optical or morphological actuation and gating.
  Journal of Colloid and Interface Science 03/2012; 369(1):231-7. · 3.07 Impact Factor
• Article: Preparation and surface properties of cashmere guard hair powders

  Kiran Patil, Rangam Rajkhowa, Xiujuan J Dai, Takuya Tsuzuki, Tong Lin, Xungai Wang
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  ABSTRACT: Cashmere guard hair, a by-product from the cashmere dehairing industry is used for low value applications because the guard hairs are not suitable for spinning as they are coarse, contain large medullation and lack crimp or curvature. To find new uses in high value-added applications, cashmere guard hairs were milled into fine particles using the processing sequence Chopping → Attritor milling → Spray Drying → Air Jet mill-ing. The guard hairs were partially hydrolysed with hydrochloric acid which increased the pulverisation rate due to the deterioration in mechanical properties. The volume median particle size d(0.5) was reduced from 2.328 μm, for untreated cashmere guard hair powder to 0.461 μm for powder from the acid hydrolysed guard hairs. FTIR and XPS studies revealed the breakdown of the cashmere guard hair cuticle cells and the exposure of the cortex on the powder surface along with the oxidation of the cashmere guard hair during milling.
  Powder Technology 01/2012; · 2.08 Impact Factor
• Article: Strip twisted electrospun nanofiber yarns: Structural effects on tensile properties

  Yaqiong Zhou, Jian Fang, Xungai Wang, Tong Lin
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  ABSTRACT: Nanofiber yarns with controlled twist levels were prepared by twisting a narrow fibrous strip cut directly from electrospun nanofiber mats. The effects of fiber morphology, diameter and orientation, as well as the yarn twist level on the yarn tensile properties were examined. For the yarns made from randomly oriented fine uniform nanofibers (e.g., diameter 359 nm) and beaded nanofibers, the tensile strength increased with increasing the yarn twist level. Higher fiber diameter (e.g., 634 nm) led to the tensile strength having an initial increase and then decrease trend. The modulus increased with the twist level for all the yarns studied. However, the elongation at break increased initially with the twist level and subsequently decreased. The orientation of aligned fibers within the fiber strip greatly influenced the yarn tensile properties. When the fibers were oriented along the fiber length direction, both tensile strength and modulus were the largest.
  Journal of materials research 01/2012; · 1.67 Impact Factor
• Article: Research Article Needleless Electrospinning of Uniform Nanofibers Using Spiral Coil Spinnerets

  Xin Wang, Haitao Niu, Xungai Wang, Tong Lin
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  ABSTRACT: Polyvinyl alcohol nanofibers were prepared by a needleless electrospinning technique using a rotating spiral wire coil as spinneret. The influences of coil dimension (e.g., coil length, coil diameter, spiral distance, and wire diameter) and operating parameters (e.g., applied voltage and spinning distance) on electrospinning process, nanofiber diameter, and fiber productivity were examined. It was found that the coil dimension had a considerable influence on the nanofiber production rate, but minor effect on the fiber diameter. The fiber production rate increased with the increased coil length or coil diameter, or the reduced spiral distance or wire diameter. Higher applied voltage or shorter collecting distance also improved the fiber production rate but had little influence on the fiber diameter. Compared with the conventional needle electrospinning, the coil electrospinning produced finer fibers with a narrower diameter distribution. A finite element method was used to analyze the electric field on the coil surface and in electrospinning zone. It was revealed that the high electric field intensity was concentrated on the coil surface, and the intensity was highly dependent on the coil dimension, which can be used to explain the electrospinning performances of coils. In addition, PAN nanofibers were prepared using the same needleless electrospinning technique to verify the improvement in productivity.
  Journal of Nanomaterials 01/2012; 785920(10). · 1.38 Impact Factor
• Article: Milled cashmere guard hair powders: Absorption properties to heavy metal ions

  Kiran Patil, Suzanne V Smith, Rangam Rajkhowa, Takuya Tsuzuki, Xungai Wang, Tong Lin
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  ABSTRACT: Cashmere guard hair was milled into fine particles using a wet milling system. The metal ion absorption properties of cashmere guard hair, both in the milled powder and its parent fibre forms, in comparison with wool and silk, were examined towards oppositely charged ionic metal species (Zn 2 + and anionic species of Cr 6 +) using respective gamma emitting radioisotopes. The absorption of metal ions was found to be gov-erned by ionic interactions over different pH ranges. The absorption performance of the powder sorbents to-wards Zn 2 + ions (silk powder > wool powder > cashmere guard hair powder) showed an opposite trend to Cr 6 + (cashmere guard hair powder > wool powder > silk power). The breakdown of cashmere guard hair cu-ticle cells and oxidation of powder surface during milling enhanced the initial rate of metal ion absorption. The absorption yield of all the studied sorbents increased with increasing the initial Cr 6 + ion concentration in the solution. However, Zn 2 + ion concentration in solution showed a very little effect on absorption in the powder sorbents studied.
  Powder Technology 01/2012; 218:262-168. · 2.08 Impact Factor