Sidra Waheed, PhD | University of Tasmania (original) (raw)

Papers by Sidra Waheed, PhD

Lab on a Chip, 2016

3D printing has the potential to significantly change the field of microfluidics. The ability to ... more 3D printing has the potential to significantly change the field of microfluidics. The ability to fabricate a complete microfluidic device in a single step from a computer model has obvious attractions, but it is the ability to create truly three dimensional structures that will provide new microfluidic capability that is challenging, if not impossible to make with existing approaches. This critical review covers the current state of 3D printing for microfluidics, focusing on the four most frequently used printing approaches: inkjet (i3DP), stereolithography (SLA), two photon polymerisation (2PP) and extrusion printing (focusing on fused deposition modeling). It discusses current achievements and limitations, and opportunities for advancement to reach 3D printing's full potential.

Applied Materials Today, 2021

Abstract The additive manufacturing (3D printing) of porous materials will open unprecedented opp... more Abstract The additive manufacturing (3D printing) of porous materials will open unprecedented opportunities to design advanced supports for extraction and separation. Here we have fabricated a reactive ZnO nanoparticle (NP)/thermoplastic composite filament for 3D printing via fused deposition modeling. The composite filament contains a 10 wt% ZnO-NPs incorporated in the thermoplastic acrylonitrile butadiene styrene (ABS). After 3D printing with the ZnO-NP/ABS filament, crystals of the zeolitic imidazolate framework-8 (ZIF-8) are grown in-situ on the 3D printed part. In-situ ZIF-8 crystallization is achieved by a mild chemical conversion mechanism at room temperature, converting the embedded ZnO nanoparticles into ZIF-8 crystals which are subsequently expressed on the surface of the 3D printed device. The resulting ZIF-8@ZnO-NP/ABS 3D printed devices were applied to the extraction of malachite green as a model water pollutant, and delivered superior performance compared with an identical device made of pure ABS, or the precursor ZnO-NP/ABS. For comparison purposes, a ZIF-8/ABS filament was fabricated with a 10 wt% load of presynthesized ZIF-8 crystals. The in-situ ZIF-8 growth approach again showed enhanced extraction performance in comparison with materials directly loaded with ZIF-8 crystals, with an increase of 48% in the extraction of malachite green. This is the first example of ZnO to ZIF-8 chemical conversion on 3D printed devices.

ACS Applied Materials & Interfaces, 2019

A relative lack of printable materials with tailored functional properties limits the applicabili... more A relative lack of printable materials with tailored functional properties limits the applicability of three-dimensional (3D) printing. In this work, a diamond-acrylonitrile butadiene styrene (ABS) composite filament for use in 3D printing was created through incorporation of high-pressure and high-temperature (HPHT) synthetic microdiamonds as a filler. Homogenously distributed diamond composite filaments, containing either 37.5 or 60 wt % microdiamonds, were formed through preblending the diamond powder with ABS, followed by subsequent multiple fiber extrusions. The thermal conductivity of the ABS base material increased from 0.17 to 0.94 W/(m·K), more than five-fold following incorporation of the microdiamonds. The elastic modulus for the 60 wt % microdiamond containing composite material increased by 41.9% with respect to pure ABS, from 1050 to 1490 MPa. The hydrophilicity also increased by 32%. A low-cost fused deposition modeling printer was customized to handle the highly abrasive composite filament by replacing the conventional (stainless-steel) filament feeding gear with a harder titanium gear. To demonstrate improved thermal performance of 3D printed devices using the new composite filament, a number of composite heat sinks were printed and characterized. Heat dissipation measurements demonstrated that 3D printed heat sinks containing 60 wt % diamond increased the thermal dissipation by 42%.

Scientific reports, Jan 8, 2017

Synthetic micro-diamond-polydimethylsiloxane (PDMS) composite microfluidic chips and thin films w... more Synthetic micro-diamond-polydimethylsiloxane (PDMS) composite microfluidic chips and thin films were produced using indirect 3D printing and spin coating fabrication techniques. Microfluidic chips containing up to 60 wt% micro-diamond were successfully cast and bonded. Physicochemical properties, including the dispersion pattern, hydrophobicity, chemical structure, elasticity and thermal characteristics of both chip and films were investigated. Scanning electron microscopy indicated that the micro-diamond particles were embedded and interconnected within the bulk material of the cast microfluidic chip, whereas in the case of thin films their increased presence at the polymer surface resulted in a reduced hydrophobicity of the composite. The elastic modulus increased from 1.28 for a PDMS control, to 4.42 MPa for the 60 wt% composite, along with a three-fold increase in thermal conductivity, from 0.15 to 0.45 W mK. Within the fluidic chips, micro-diamond incorporation enhanced heat di...

Lab on a Chip, 2016

3D printing has the potential to significantly change the field of microfluidics.

Additive manufacturing, or 3D printing, continues to impact manufacturing and prototyping industr... more Additive manufacturing, or 3D printing, continues to impact manufacturing and prototyping industries, through the provision of a quick and low-cost alternative to the more conventional subtractive manufacturing techniques. However, due to the intrinsically limited functionality of most proprietary resins and commercially available pristine feedstock polymers, there is now a critical need to develop printable composites with high-performance and improved physico-mechanical features and varied functional properties. This research project focuses on exploring the potential of new functional 3D printable materials, such that 3D printing technology can develop further and deliver in new application areas. This thesis documents research on the development of novel, print-compatible functional composites, followed by the investigation of their physico-chemical properties, with potential applications in the area of microfluidic, microanalytical and micro-electronic-mechanical platforms. Cha...

ACS Applied Materials & Interfaces, 2020

Desalination, 2015

• 2-stage phase inversion protocol; involving TIPS and controlled evaporation. • Silica is used a... more • 2-stage phase inversion protocol; involving TIPS and controlled evaporation. • Silica is used as an additive to augment permeation performance. • Addition of silica enhanced the fouling resistance remarkably. • Optimum loading of silica particle is required for maximum performance.

Desalination, 2014

ABSTRACT In this work, a number of cellulose acetate/polyethylene glycol-600 membranes, with diff... more ABSTRACT In this work, a number of cellulose acetate/polyethylene glycol-600 membranes, with different ratios were prepared by 2-stage phase inversion protocol. The permeation properties were studied by subjecting membranes in indigenously fabricated reverse osmosis plant. The flux and salt rejection of membranes were determined. The membrane with highest salt rejection was selected for modification with chitosan. The modified membranes were characterized for their compositional analysis, surface roughness, surface morphology, permeation properties, membrane hydraulic resistance and antibacterial activity. The presence of functional group was determined by FTIR spectra. Chitosan was found to significantly enhance the salt rejection and membrane hydraulic resistance. All modified membranes exhibited remarkable antibacterial properties. The varying nature of nodules and interstices spaces was observed in the images obtained by the atomic forced microscopy. The asymmetric surface morphology of membranes was elucidated from the scanning electron microscope. The synthesis of cellulose acetate membrane, doped with polyethylene glycol and modified with chitosan, provides a convenient access towards the development of sustainable chemistry.

Analytica Chimica Acta, 2019

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Journal of Separation Science

American Chemical Society, 2019

A relative lack of printable materials with tailored functional properties limits the applicabili... more A relative lack of printable materials with tailored functional properties limits the applicability of three-dimensional (3D) printing. In this work, a diamond–acrylonitrile butadiene styrene (ABS) composite filament for use in 3D printing was created through incorporation of high-pressure and high-temperature (HPHT) synthetic microdiamonds as a filler. Homogenously distributed diamond composite filaments, containing either 37.5 or 60 wt % microdiamonds, were formed through preblending the diamond powder with ABS, followed by subsequent multiple fiber extrusions. The thermal conductivity of the ABS base material increased from 0.17 to 0.94 W/(m·K), more than five-fold following incorporation of the microdiamonds. The elastic modulus for the 60 wt % microdiamond containing composite material increased by 41.9% with respect to pure ABS, from 1050 to 1490 MPa. The hydrophilicity also increased by 32%. A low-cost fused deposition modeling printer was customized to handle the highly abrasive composite filament by replacing the conventional (stainless-steel) filament feeding gear with a harder titanium gear. To demonstrate improved thermal performance of 3D printed devices using the new composite filament, a number of composite heat sinks were printed and characterized. Heat dissipation measurements demonstrated that 3D printed heat sinks containing 60 wt % diamond increased the thermal dissipation by 42%.

: Humidity sensing is of significant interest to monitor and control the moisture sensitive envir... more : Humidity sensing is of significant interest to monitor and control the
moisture sensitive environments. Here, we developed a novel 3D printable composite
consisting of boron-doped diamond (BDD) (60 wt %) and LiCl (2 wt %) in
acrylonitrile butadiene styrene (ABS). SEM analysis of the composite material
confirmed the uniform distribution of the BDD and presence of a thin layer of LiCl
distributed throughout the matrix. The developed composite material was employed
for simple and quick (∼2 min) fabrication of the humidity sensor using low cost
fused deposition modeling (FDM) 3D printer. The unique composite material
allowed the fabrication of one-piece 3D printed sensor in comparison to traditional
multicomponent (e.g., support, sensitive film, and electrodes) humidity sensing
devices. The resulting humidity sensor showed excellent sensitivity with up to 125-
fold change in resistance for the range of 11−97% relative humidity. The quick
response (60 s, n = 3, RSD= 18.7%) and the recovery time (120 s, n = 3, RSD =
16.6%) is attributed to the uniform distribution of the BDD electrode material and
strong networking with the LiCl layer distributed throughout the matrix. Long-term stability and repeatability was evaluated, with
relative standard deviation of the response of less than 15% obtained over a test period of 14 days. When applied as a sensor for
humidity in human breath, the response curves obtained for 12 consecutive breath cycles with post-breath compressed air-drying,
showed excellent repeatability and sensitivity, with quick response and recovery (13 s, n = 12, RSD = 15%). The developed 3D
printable humidity sensing material was also used to fabricate a customized 3D printed sensor for monitoring the humidity of the N2
supply.

Carbohydrate Polymers, 2016

Materials Today: Proceedings, 2015

Journal of the Taiwan Institute of Chemical Engineers, 2015

In order to tap the seemingly boundless problem of water scarcity, reverse osmosis (RO), has been... more In order to tap the seemingly boundless problem of water scarcity, reverse osmosis (RO), has been formulated as a significant solution. However, RO technology, suffers by a major challenge of biofouling, which results in reduced production capacity and increased operation costs. Thus, there is an urgent demand to fabricate an appropriate disinfection membrane surface with maximum permeation performance. In this work, cellulose acetate/poly ethylene glycol membranes impregnated with silver particles were prepared by 2-stage phase inversion protocol. The Modified membranes were characterized for their compositional analysis, surface roughness, surface morphology, permeation properties, membrane hydraulic resistance and antibacterial activity. The presence of functional group was determined by FTIR spectra. The asymmetric surface morphology of membranes was elucidated from the scanning electron microscope. The varying nature of nodules and interstices spaces was observed in the images obtained by the atomic forced microscopy. The progressive decreased was observed in the surface roughness of membranes. The modification has significantly increased the flux and salt rejection capacity of membranes. All modified membranes exhibited remarkable antibacterial properties against gram negative Escherichia Coli. The synthesis of cellulose acetate membrane, doped with polyethylene glycol and modified with silver, provides a convenient way for the development of selfsterilized membranes. of non-conventional water sources, such as seawater or ocean water is of considerable interest due to the usual immediate proximity of such water sources for areas that are highly water-stressed [7]. Desalination of sea or saline water has been practiced regularly for over 50 years and is a well-established means of water supply in many countries . Two main directions have evolved the desalination technology, namely evaporation and membrane techniques. Among various membrane processes, reverse osmosis (RO) is the most prevalent processes as it offers multiple advantages such as low energy consumption, environmental friendliness, simplicity, elevated recovery rate and high salt rejection [9,10].

3D printing has the potential to significantly change the field of microfluidics. The ability to ... more 3D printing has the potential to significantly change the field of microfluidics. The ability to fabricate a complete microfluidic device in a single step from a computer model has obvious attractions, but it is the ability to create truly three dimensional structures that will provide new microfluidic capability that is challenging , if not impossible to make with existing approaches. This critical review covers the current state of 3D printing for microfluidics, focusing on the four most frequently used printing approaches: inkjet (i3DP), stereolithography (SLA), two photon polymerisation (2PP) and extrusion printing (focusing on fused deposi-tion modeling). It discusses current achievements and limitations, and opportunities for advancement to reach 3D printing's full potential.

In this work, a series of cellulose acetate/polyethylene glycol-600 membranes, with varying ratio... more In this work, a series of cellulose acetate/polyethylene glycol-600 membranes, with varying ratios were prepared
by 2-stage phase inversion protocol. The permeation properties were studied by subjecting membranes in indigenously
fabricated reverse osmosis plant. After optimization of different CA/PEG ratios, themembranewith highest
salt rejection capacity was selected and modified with varying amount of silica. The Modified membranes were
characterized for their permeation properties, hydrophilicity, compositional analysis, thermal stability,mechanical
strength and morphological studies. Silica significantly influenced the permeation performance of composite
membrane. The flux enhanced from 0.35 to 2.46 L/h m2 along with an 11.41% relative increase in salt rejection.
The hydrophilicity was significantly enhanced by the addition of silica. In FTIR spectra, the broadening of the
peak around 3500 cm−1 and emergence of peak at 950 cm−1 specified the incorporation of silica particles. The
thermal analysis indicated the relative increase in degradation temperature (Tmax) and glass transition temperature
(Tg) for CPS-5 membrane. The mechanical stability of the modified membranes, increased initially, but
declined with further addition of silica. The results indicated that the incorporation of SiO2 content in the casting
solution improved the fouling resistance of the membranes.

In this work, a number of cellulose acetate/polyethylene glycol-600 membranes, with different rat... more In this work, a number of cellulose acetate/polyethylene glycol-600 membranes, with different ratios were
prepared by 2-stage phase inversion protocol. The permeation propertieswere studied by subjecting membranes
in indigenously fabricated reverse osmosis plant. The flux and salt rejection of membranes were determined. The
membrane with highest salt rejection was selected for modification with chitosan. The modified membranes
were characterized for their compositional analysis, surface roughness, surface morphology, permeation properties,
membrane hydraulic resistance and antibacterial activity. The presence of functional group was determined
by FTIR spectra. Chitosan was found to significantly enhance the salt rejection and membrane hydraulic
resistance. All modified membranes exhibited remarkable antibacterial properties. The varying nature of nodules
and interstices spaces was observed in the images obtained by the atomic forced microscopy. The asymmetric
surface morphology of membranes was elucidated from the scanning electron microscope. The synthesis of
cellulose acetate membrane, doped with polyethylene glycol and modified with chitosan, provides a convenient
access towards the development of sustainable chemistry.

Lab on a Chip, 2016

Applied Materials Today, 2021

ACS Applied Materials & Interfaces, 2019

Scientific reports, Jan 8, 2017

Lab on a Chip, 2016

3D printing has the potential to significantly change the field of microfluidics.

ACS Applied Materials & Interfaces, 2020

Desalination, 2015

Desalination, 2014

Analytica Chimica Acta, 2019

Journal of Separation Science

American Chemical Society, 2019

A relative lack of printable materials with tailored functional properties limits the applicabili... more A relative lack of printable materials with tailored functional properties limits the applicability of three-dimensional (3D) printing. In this work, a diamond–acrylonitrile butadiene styrene (ABS) composite filament for use in 3D printing was created through incorporation of high-pressure and high-temperature (HPHT) synthetic microdiamonds as a filler. Homogenously distributed diamond composite filaments, containing either 37.5 or 60 wt % microdiamonds, were formed through preblending the diamond powder with ABS, followed by subsequent multiple fiber extrusions. The thermal conductivity of the ABS base material increased from 0.17 to 0.94 W/(m·K), more than five-fold following incorporation of the microdiamonds. The elastic modulus for the 60 wt % microdiamond containing composite material increased by 41.9% with respect to pure ABS, from 1050 to 1490 MPa. The hydrophilicity also increased by 32%. A low-cost fused deposition modeling printer was customized to handle the highly abrasive composite filament by replacing the conventional (stainless-steel) filament feeding gear with a harder titanium gear. To demonstrate improved thermal performance of 3D printed devices using the new composite filament, a number of composite heat sinks were printed and characterized. Heat dissipation measurements demonstrated that 3D printed heat sinks containing 60 wt % diamond increased the thermal dissipation by 42%.

Carbohydrate Polymers, 2016

Materials Today: Proceedings, 2015

Journal of the Taiwan Institute of Chemical Engineers, 2015

3D printing has the potential to significantly change the field of microfluidics. The ability to ... more 3D printing has the potential to significantly change the field of microfluidics. The ability to fabricate a complete microfluidic device in a single step from a computer model has obvious attractions, but it is the ability to create truly three dimensional structures that will provide new microfluidic capability that is challenging , if not impossible to make with existing approaches. This critical review covers the current state of 3D printing for microfluidics, focusing on the four most frequently used printing approaches: inkjet (i3DP), stereolithography (SLA), two photon polymerisation (2PP) and extrusion printing (focusing on fused deposi-tion modeling). It discusses current achievements and limitations, and opportunities for advancement to reach 3D printing's full potential.