Polymethyl Methacrylate Content Research Articles

Effect of PMMA pore former on mechanical strength and performance of glass fibre metal-bonded porous diamond blocks with Cu–Sn–Ti solder alloys

To develop a metal-bonded diamond tool that does not require frequent dressing during grinding, a novel glass fibre metal-bonded porous diamond block is proposed. The effect of the content percentage and particle size of polymethyl methacrylate (PMMA) pore formers on the porosity of porous diamond blocks was investigated. The Vickers hardness and bending strength of the porous blocks with and without diamonds were tested. Wear tests were performed on the porous diamond blocks. The results show that an increase in the PMMA content (1.75–9.45 wt%) caused an increase in the porosity (2.8 %–22.9 %) and a decrease in the bending strength (8.6 %–71.9 %) and Vickers hardness (22.1 %–54.3 %), compared to those of the blocks without PMMA. An increase of PMMA size (20–40 μm diameter) caused an increase in the porosity (2 %–11.6 %), and a decrease in the bending strength (34.1 %–42.7 %) and Vickers hardness (23.7 %, 40.5 %), compared to those of the blocks without PMMA. However, excessively large PMMA particles (50–70 μm diameter) caused a decrease in the porosity and an increase in the bending strength and Vickers hardness. Increasing the porosity of the diamond blocks appropriately can reduce the need for frequent dressing and enhance the SiC removal rate. However, excessive porosity tends to accelerate diamond wear, leading to a decrease in the SiC removal rate.

Study on mechanical properties of vacuum‐infused glass fiber reinforced thermoplastic methacrylic resin composites

AbstractIn recent years, the growing environmental awareness has prompted increased attention towards the substitution of nonrecyclable thermosetting epoxy resin composite materials with recyclable thermoplastic composite materials. The objective of this study is to utilize a laboratory‐made polymethyl methacrylate (PMMA)/methyl methacrylate (MMA) binary liquid resin (PMBLR) to prepare thermoplastic resin/glass fiber (GF) composite materials using the vacuum‐assisted perfusion method. These composites are then compared with GF‐reinforced thermosetting epoxy resin composites. The investigation reveals a significant influence of benzoyl peroxide (BPO) content on the mechanical properties of pure MMA and PMBLR casting resins, which also incorporate N‐methyl‐N‐((1‐methyl‐1H‐indol‐3‐yl) methyl) aniline (DMA) as redox composite initiators. The optimal mechanical properties for both types of casting resins are achieved at a DMA:BPO:MMA ratio of 0.5:1.2:100. Additionally, at a PMMA concentration of 24 wt% in PMBLR under this specific initiator ratio, the composites demonstrate the most desirable properties. Furthermore, a comparative analysis of PMBLR/GF composites and epoxy/GF composites indicates that the former exhibit superior 90° tensile strength, bending strength, and short beam shear strength. The fracture morphology analysis highlights discernible micro‐ductile fracture characteristics in PMBLR/GF composites, distinguishing them from epoxy/GF composites. Dynamic thermomechanical analysis (DMA) results further reveal a higher storage modulus and loss factor in PMBLR/GF composites when compared to epoxy/GF composites.Highlights Glass fiber‐reinforced composites were fabricated at ambient temperature. A degradable PMMA/MMA binary thermoplastic resin (PMBLR) was developed as a replacement for non‐degradable epoxy. PMBLR composites exhibit enhanced strength compared to epoxy: tensile (+18.8%), bending (+27.4%), and short beam shear (+34.3%).

Investigation on electric properties of 0.57(Bi0.8La0.2)FeO3‐0.43PbTiO3 porous ceramics prepared by burnable plastic sphere method

AbstractIn this study, 0.57(Bi0.8La0.2)FeO3‐0.43PbTiO3 (BLF‐PT) porous ceramics were fabricated by the burnable plastic sphere method using polymethyl methacrylate (PMMA) as a pore forming agent. X‐ray diffraction results reveal that BLF‐PT porous ceramics mixed with tetragonal and rhombohedral phases display the single perovskite structure, changing little for different porosities. Scanning electron microscope images show that porosity of BLF‐PT ceramics increases with the increase of PMMA content with average grain size of 3.2–3.5 μm. Different from the continuous decrease of dielectric constant εr and remnant polarization Pr, piezoelectric constant d33 of BLF‐PT porous ceramics increases initially but then drops with the increase of porosity that reaches to the maximum of 230 pC/N at porosity of 8.5 vol.%. The abnormal enhancement of piezoelectric property is attributed to the unique three‐dimensional grid porous ceramic skeleton and uniformly distributed grain size. Moreover, acoustic impedance Z of BLF‐PT porous ceramic is 11.2 MRayls at porosity of 24.3 vol.% comparing with that of 17.7 MRayls for bulk ceramics, which reduces by 58%. BLF‐PT porous ceramics at lower porosity with enhanced piezoelectric and acoustic matching performances have a great potential in the fields of underwater acoustic transducers and medical ultrasonic diagnosis.

Fabrication of poly(vinylidene fluoride)‐based composite powder coating with enhanced adhesion performance

AbstractGiven the environmental benefits, poly(vinylidene fluoride) (PVDF)‐based composite powder coating was developed without using any harmful solvent. However, it still remains poor adhesion to substrates and low compatibility to acrylic resin issues. To address these challenges, PVDF was grafted with glycidyl methacrylate (GMA) through a facile and scalable reactive extrusion method. The resulting product, PVDF‐g‐GMA, was then mixed with different contents of polymethyl methacrylate (PMMA), and the mixing was sprayed onto aluminum substrates. The PVDF‐g‐GMA/PMMA powder coating shows the excellent adhesion and corrosion resistance, particularly when the PMMA content is 30 wt%, owning to the good compatibility of PVDF‐g‐GMA and PMMA. This work opens up a new possibilities for the development of advanced composite powder coatings with improved performance characteristics.

Tungsten-based polymer composite, a new lead-free material for efficient shielding of coupled neutron-gamma radiation fields: A FLUKA simulation study

Abstract Metal-based polymer composites, a new category of advanced materials, are advantageous for effective protection of radiation field. Recent report of fabrication of tungsten (W)-Poly methyl methacrylate (PMMA) composite microcellular foams with enhanced mechanical strength properties opens up the possibility of its use in radiation attenuation. Objective of this theoretical study is to assess the efficacy of W-based polymer composite, a new lead-free shielding material for attenuating coupled neutron-gamma radiations. Current paper utilizes open-source Monte Carlo code FLUKA to evaluate shielding efficiency of PMMA composites reinforced with varying concentration W particles. Study shows that, adding even 20 vol% of W particles can significantly improve radiation shielding ability of PMMA. Performance of analogous composition Pb-based polymer composite is also examined to demonstrate its inadequacy in radiation protection compared to W-based composite. Study reveals an interesting fact that for any shield dimension, total radiation dose follows an initial descending trend with increase in heavy metal (W/Pb) proportion up to certain optimum value where dose becomes minimum, beyond that dose increases. Optimum heavy metal concentrations are found to be 70 vol% and 30 vol% for W and Pb respectively, with minimum dose for Pb shield being two orders of higher magnitude. Study is further extended to investigate shielding efficiency of conventional double-layer laminates employing W and PMMA in both high-Z/low-Z and low-Z/high-Z configurations as well as optimum concentration of W-PMMA composite and PMMA. It is shown that among all the potential designs, newly introduced composite-based double-layer shield performs best in terms of volumetric dose while single-layer optimized composite shield offers least specific dose.

Influence of the content of polymethyl methacrylate on the properties of porous Si3N4 ceramics fabricated by digital light processing

Porous Si3N4 ceramics are highly regarded as ideal materials for radomes due to their unique characteristics. However, the slurry used for the preparation of porous Si3N4 ceramics suffers from a low cure depth, making it challenging to fabricate ceramic components using DLP technology. In this study, porous Si3N4 ceramics were prepared by combining DLP technology with pore-forming agent method. The addition of polymethyl methacrylate (PMMA) powders with lower refractive index than that of Si3N4 powders can improve the penetration depth of ultraviolet light in the Si3N4 slurry. A systematic study was conducted to investigate the influence of the addition of PMMA powders on the properties of Si3N4 slurries and porous Si3N4 ceramics. When PMMA powders were added at 10 wt%, the slurry with a lowest viscosity of 0.13 Pa s (the shear rate is 30 s−1) and cure depth of 40.0 μm (the exposure energy is 600 mJ/cm2) was obtained. With the increase of PMMA content, porous Si3N4 ceramics experienced a gradual decrease in both the flexural strength and bulk density, while the porosity increased from 14.41% to 27.62%. Specifically, when 20 wt% PMMA was added, the resulting porous Si3N4 ceramics had a lowest bulk density (2.41 g/cm3), a maximum porosity (27.62%), and a flexural strength (435.87 MPa). The study is of great significance in establishing an experimental foundation for fabricating porous Si3N4 ceramics by using DLP technology.

Polymer-mixed Sb2Te3/Te nanocomposites exhibiting p-type to n-type conduction reversal and thermal conductivity reduction

Sb2Te3-based materials are potential room-temperature thermoelectric materials. In the present work, we choose polycrystalline Sb2Te3/Te nanocomposites and utilize Poly Methyl Methacrylate (PMMA) to reduce the thermal conductivity of Sb2Te3 samples. PMMA and polycrystalline Sb2Te3/Te were well mixed using ball milling. Pellets have been made by the cold press method. Thermoelectric transport properties of Sb2Te3/Te nanocomposites: composition, microstructure, and analysis are found to be influenced by PMMA. With increasing PMMA concentration a p-type to n-type transition has been observed because there are fewer charge carriers or the composites have a higher resistance. It is also observed that the thermal conductivity of Sb2Te3/Te nanocomposites decreases as the PMMA increases. This research paves the way for making the best thermoelectric materials by reducing thermal conductivity through the use of polymers.

A composite of polymethylmethacrylate, hydroxyapatite, and β-tricalcium phosphate for bone regeneration in an osteoporotic rat model.

The purpose of this study was to test several modifications of the polymethylmethacrylate (PMMA) bone cement by incorporating osteoconductive and biodegradable materials for enhancing bone regeneration capacity in an osteoporotic rat model. Three bio-composites (PHT-1 [80% PMMA, 16% HA, 4% β-TCP], PHT-2 [70% PMMA, 24% HA, 6% β-TCP], and PHT-3 [30% PMMA, 56% HA, 14% β-TCP]) were prepared using different concentrations of PMMA, hydroxyapatite (HA), and β-tricalcium phosphate (β-TCP). Their morphological structure was then examined using a scanning electron microscope (SEM) and mechanical properties were determined using a MTS 858 Bionics test machine (MTS, Minneapolis, MN, USA). For in vivo studies, 35 female Wister rats (250 g, 12 weeks of age) were prepared and divided into five groups including a sham group (control), an ovariectomy-induced osteoporosis group (OVX), an OVX with pure PMMA group (PMMA), an OVX with PHT-2 group (PHT-2), and an OVX with PHT-3 group (PHT-3). In vivo bone regeneration efficacy was assessed using micro-CT and histological analysis after injecting the prepared bone cement into the tibial defects of osteoporotic rats. SEM investigation showed that the PHT-3 sample had the highest porosity and roughness among all samples. In comparison to other samples, the PHT-3 exhibited favorable mechanical properties for use in vertebroplasty procedures. Micro-CT and histological analysis of OVX-induced osteoporotic rats revealed that PHT-3 was more effective in regenerating bone and restoring bone density than other samples. This study suggests that the PHT-3 bio-composite can be a promising candidate for treating osteoporosis-related vertebral fractures.

Three-dimensional printing of a high-impact resistant polylactic acid-based ternary polymer blend

Three-dimensional printing of polylactic acid (PLA)-based polymer blends has several benefits, including low cost, dimensional accuracy and tunability of mechanical properties. Although the addition of Polybutylene adipate terephthalate (PBAT) into PLA improves the ductility of the blend, the two polymers are immiscible. This work introduced polymethyl methacrylate (PMMA) into PLA/PBAT blends as a compatibiliser to improve the interfacial interaction between PLA and PBAT phases. PLA/PBAT/PMMA blends were prepared with varying concentrations of PLA, PBAT (10–20 wt%) and PMMA (0–6 wt%) for 3D printing applications. The mechanical and thermal behaviours of the PLA/PBAT/PMMA ternary blends and their suitability for 3D printing were investigated. The thermal properties of the blends were used to determine the 3D printing nozzle temperature and bed temperature. Three-dimensional printing of the polymer blends was carried out using a Bowden extruder 3D printer. Additionally, the compatibilisation effects of PMMA and interfacial interaction of the polymer phases were investigated using SEM analysis.

Preparation of three-dimensionally linked pore-like porous atomized ceramics with high oil and water absorption rates

Ceramic atomization cores are a new application of porous ceramics; however, the challenging regulation of the pore structures of porous ceramics has limited their application. To improve the low liquid absorption rates and low liquid storage capacity of porous ceramics in the field of atomization, this study used three substances, polymethyl methacrylate (PMMA), starch, and diatomaceous earth, to produce porous ceramics with a three-dimensional interconnected triple-porous structure by sacrificial templating. In the porous ceramics, large pores resulting from PMMA increase liquid storing capacity, medium pores resulting from the starch facilitate the transport of liquid, and small pores resulting from diatomaceous earth enhance capillary action, significantly increasing the rate of liquid absorption. By varying the PMMA contents and type of starch in the preform, water and oil storage capacities of up to 123% and 143%, respectively, can be achieved. We found that an optimized porous ceramic with dimensions of 15 mm × 15 mm × 15 mm absorbs water rapidly (reaching saturation in only 1.67 s), demonstrates good solid–liquid properties and shape stability, and is recyclable (requires drying before reuse). The proposed porous ceramics have promising atomization core and oil–water separation applications.

Characterization and Solution Properties of Poly(Methyl Metha-Acrylate) – Poly(Ethylene Glycol) Blends

Measurements of viscosity of poly methyl methacrylate (PMMA)/poly ethylene glycol (PEG) blends in tetra hydro furan (THF) as a common solvent, were carried out for different blend compositions at 30, 40 and 50°C. Using the viscosity data, interaction parameters µ were computed to determine miscibility. These values revealed that the blend was miscible when the PMMA content was more than 30% of the blend. Further, the results revealed that the change in temperature has significant effect on the miscibility of PMMA/PEG polymer blends. The simple of (PMMA/PEG) blends were characterized by using (FTIR).

Tissue Remodeling After Implantation with Polymethylmethacrylate: An Experimental Study in Mice.

Polymethylmethacrylate (PMMA) is a filler used for aesthetic and/or repair purposes. The response to the implantation of biomaterials varies according to factors related to the patient, the professional responsible for the application and the material used. In vitro and in vivo experimental models have been used to study aspects such as the organism/biomaterial interface and the role of macrophages, dendritic cells and neutrophils. This study aimed to characterize the inflammatory reactions related to polymer concentration, implantation depth and exposure time. Different concentrations of PMMA were implanted in different anatomical planes in mice. The consequences of contact with PMMA, from structural changes to the inflammatory characteristic of tissue damage, were histologically evaluated. The implantation interfered in the morphological structure of the region where it was implanted, expanding it and due to the inflammatory reaction generated, by the presence of the vehicle in the initial phase and by the collagen produced in the chronic phase. The 30% concentration of PMMA induced a greater presence of foreign body giant cells both subcutaneously, at 7, 30 and 90 days after implantation (DAI), and intramuscular at 30DAI. Tissue remodeling was more expressive in the subcutaneous region with significant density of the extracellular matrix at 90DAI. In conclusion, the foreign body reaction resulting from the implantation process acquires different characteristics depending on the anatomical plane and the concentration of implanted product, where the more superficial the implantation plane, the greater the inflammatory reaction. Moreover, PMMA concentration and the depth of implantation did not influence the collagen production.No Level Assigned This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors https://www.springer.com/00266.

Characterization of various acrylate based artificial teeth for denture fabrication

Acrylic resins-based artificial teeth are frequently used for the fabrication of dentures has and contribute a very strong share in the global market. However, the scientific literature reporting the comparative analysis data of various artificial teeth is scarce. Focusing on that, the present study investigated various types of commercially available artificial teeth, composed of polymethyl methacrylate (PMMA). Artificial teeth are characterized for chemical analysis, morphological features, thermal analysis, and mechanical properties (surface hardness, compressive strength). Different types of artificial teeth showed distinct mechanical (compression strength, Vickers hardness) and thermal properties (thermal gravimetric analysis) which may be attributed to the difference in the content of PMMA and type and quantity of different fillers in their composition. Thermogravimetric analysis (TGA) results exhibited that vinyl end groups of PMMA degraded above 200 °C, whereas 340–400 °C maximum degradation temperature was measured by differential thermal analysis (DTA) for all samples. Crisma brand showed the highest compressive strength and young modulus (88.6 MPa and 1654 MPa) while the lowest value of Vickers hardness was demonstrated by Pigeon and Vital brands. Scanning electron microscope (SEM) photographs showed that Crisma, Pigeon, and Vital exhibited characteristics of a brittle fracture; however, Artis and Well bite brands contained elongated voids on their surfaces. According to the mechanical analysis and SEM data, Well bite teeth showed a significantly higher mechanical strength compared to other groups. However, no considerable difference was observed in Vickers hardness of all groups.Graphical abstract

Tuning the Sensitivity and Dynamic Range of Optical Oxygen Sensing Films by Blending Various Polymer Matrices.

In this work, eight different types of optical oxygen sensing films were prepared by impregnating indicator and matrix solution on the surface of a polypropylene microporous filter membrane. The polymer matrix of the sensing films was ethyl cellulose (EC), polymethyl methacrylate (PMMA), and their blends with different mixing ratios. Scanning electron microscopy (SEM), laser confocal microscopy, and fluorescence spectrometer were used to investigate the morphologies and optical properties of the sensing films. Phase delay measurements under different oxygen partial pressures (PO2) and temperatures were applied to investigate the analytical performances of the sensing film for gaseous O2 monitoring. Results show that the response time of all the sensing films was extremely fast. The sensitivities and dynamic ranges of the sensing films with the blended polymer matrix were separately decreased and increased as the EC/PMMA ratio decreased, and the S-V curve of the sensing films blended with equal content of EC and PMMA exhibited good linearity under different temperatures, showing a promising prospect in practical application.

Cytocompatibility of Polymethyl Methacrylate Honeycomb-like Pattern on Perfluorinated Polymer.

In this study, we present a simple approach for developing a biocompatible polymer scaffold with a honeycomb-like micropattern. We aimed to combine a plasma treatment of fluorinated ethylene propylene (FEP) substrate with an improved phase separation technique. The plasma exposure served for modification of the polymer surface properties, such as roughness, surface chemistry, and wettability. The treated FEP substrate was applied for the growth of a honeycomb-like pattern from a solution of polymethyl methacrylate (PMMA). The properties of the pattern were strongly dependent on the conditions of plasma exposure of the FEP substrate. The physico-chemical properties of the prepared pattern, such as changes in wettability, aging, morphology, and surface chemistry, were determined. Further, we have examined the cellular response of human osteoblasts (U-2 OS) on the modified substrates. The micropattern prepared with a selected combination of surface activation and amount of PMMA for honeycomb construction showed a positive effect on U-2 OS cell adhesion and proliferation. Samples with higher PMMA content (3 and 4 g) formed more periodic hexagonal structures on the surface compared to its lower amount (1 and 2 g), which led to a significant increase in the pattern cytocompatibility compared to pristine or plasma-treated FEP.

Fabrication of porous PZT ceramics using micro-stereolithography technology

Based on micro-stereolithography (μSL) additive manufacturing (AM) followed by the use of the burnable plastic sphere (BURPS) technique, we present the fabrication of porous lead zirconate titanate (PZT) ceramics. A printing slurry was prepared by mixing photocurable ceramic suspensions with various contents of polymethylmethacrylate (PMMA) as a pore-forming agent (PFA). We found that the cure depth increased gradually with increasing PMMA content. The sintered PZT ceramics exhibited a porous microstructure of predominantly spherical pores formed by PMMA, with sizes ranging from ~15 to 35 μm. The porosity of the PZT ceramics increased from 11.3% to 21.9%, corresponding to a decrease in the density from 6.92 to 6.09 g/cm3 due to the increasing PMMA content. As the porosity increased, the acoustic impedance decreased from 24.4 to 12.6 MRayls (106 kg/m2 s). The porous PZT ceramic with 5 wt% PMMA exhibited superior dielectric and piezoelectric properties (d33 = 525 pC/N, εr = 2417, tanδ = 0.04) that were comparable to those of ceramics fabricated by conventional methods. These results suggest that μSL technology is a viable alternative for fabricating porous PZT ceramic components, especially pieces with complex geometric structures.

A novel fabrication procedure for producing high strength hydroxyapatite ceramic scaffolds with high porosity

Hydroxyapatite (HA) scaffolds were fabricated using the space holder method with a pressureless sintering process in a systematically developed manner at different fabrication stages to increase the strength of the scaffold at high porosity. Polyvinyl alcohol (PVA) and Polymethyl methacrylate (PMMA) were used as binders and space holder agents, respectively. The physical properties of the HA scaffolds were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), linear shrinkage test, and porosity measurements. The mechanical properties of the HA scaffolds were analyzed using compressive strength measurements. The results revealed that the HA scaffold met the expected quality requirements with a compressive strength of 2.2 MPa at a porosity of 65.6% with pore sizes distributed in the range of 126–385 μm. The shrinkage of the scaffold diameter occurred by 20.27%, this diameter shrinkage predominantly to the shrinkage of the HA scaffold caused by sintering. Besides, suspect that a higher PMMA concentration causes pore size shrinkage upon sintering. The formation of pore interconnections was evidenced by SEM observations and the ‘translucent light method’ developed in this study. The results of the scaffold phase test using XRD showed that the final scaffold consisted only of the HA phase, as the PVA and PMMA phases burned out during the sintering process.

Reaction zone structure and detonation parameters of nitromethane/polymethylmethacrylate and its mixture with microballoons

In the present work, the detonation wave structure and detonation parameters for nitromethane (NM) and its mixtures with polymethylmethacrylate (PMMA) and glass microballoons (GMB) were studied by a velocity interferometer system for any reflector laser interferometer. The PMMA concentration varied from 2% to 4%. It is shown that PMMA additives lead to a change in the reaction zone structure, which can be observed as an appearance of a cellular instability of the detonation front. The detonation parameters of the mixture up to 3% PMMA are close to those of pure nitromethane and reduced when 4% PMMA is added. The addition of 2% GMB to the NM/PMMA mixture leads to the formation of a detonation front with a characteristic size of heterogeneities on the order of GMB diameter. In this case, the detonation parameters are reduced, and the values of the detonation velocity decrease by about 10% compared to NM/PMMA mixtures.

Photophysics behind luminescence phenomenon in conducting conjugate polymer blends for application as an emissive layer in PLEDs

Luminescence quenching by polarons is an important loss mechanism in polymer light-emitting diodes (PLEDs). Steady-state and time-resolved photoluminescence spectroscopy of polyaniline (PAni) thin films with varying polaron doping has helped us to realize polaron density-dependent photoluminescence quenching mechanisms inside the thin films. A sharp reduction in photoluminescence emission spectra has been observed at doping densities between 1017 and 1019 cm−3. This doping concentration-dependent photoluminescence phenomenon in PAni is modeled quantitatively using quenching of excitons by polarons through long-range Förster resonance energy transfer (FRET) and short-range charge transfer (CT) mechanisms. The results match well with the experimental findings that demonstrate that both models need to be considered to explain the mechanisms of luminescence quenching. FRET and CT phenomena inside an emissive layer of PLEDs have been demonstrated to play a pivotal role in the quantum efficiency roll-off phenomenon at high current density using experimentally obtained and theoretically calculated kinetic quenching parameters. To get rid of low luminescence in PAni, it has been blended with poly(methyl) methacrylate (PMMA) that enhances its luminescence manifold. The blending of PMMA leads to the introduction of a new photophysical phenomenon—donor PMMA concentration-dependent FRET contrary to original FRET theory proposed by Förster. Concentration-dependent FRET leads to a sharp drop in luminescence from the polymer blend after reaching a critical concentration of PMMA. Therefore, the present study explores the reason behind low luminescence in conducting polymers and demonstrates ways to mitigate it along with providing an account of the photo-physics of the conducting polymer as an emissive layer in PLEDs.

Hydrothermal growth of overlapping ZnO nanorod arrays on the porous substrate and their H2 gas sensing

ZnO nanorod arrays (ZNAs) were prepared on a metakaolin (MK)-based porous substrate via a seeding-hydrothermal method. The spherical poly methyl methacrylate (PMMA) microspheres were employed as the pore former to obtain homogeneous porous structure on the MK-based substrates. Various characterization methods were used to investigate the effects of the porous structure on the morphological and structural properties of the ZNAs. The results indicated that the alignment degree of the ZNAs decreased significantly with the enhancement of the apparent porosity of the substrate. The ZNAs prepared on the MK-based substrate with the PMMA content of 30 wt% exhibited an overlapping morphology with an average diameter and length of 88 nm and 570 nm, respectively. Gas sensing measurements revealed that the response value of the overlapping ZNAs to 1000 ppm H2 at the operating temperature of 225 °C was 9.2, which is four times higher than that of the vertical ZNAs grown on the MK-based non-porous substrate. It confirms that the porous structure of the as-prepared substrates favors for the growth of the overlapping ZNAs, and the enhanced H2 gas sensing performance might be primarily related to the more effective adsorption sites and the modulation of the potential barrier at the junctions of the overlapping morphology.