Glass polyalkenoate cements (GPCs) are important dental materials that chemically bond to teeth. This study investigated modifying GPCs by adding montmorillonite clay (MMT) to improve their compressive strength and altering their glass composition to change their setting reaction kinetics. FTIR analysis showed MMT addition increased COO-M+ peak intensity over time, indicating improved crosslinking. Compressive strength testing found MMT increased strengths for both glass compositions. The glass with sodium showed slower setting than the sodium-free glass based on weaker COO-M+ peaks and shoulder peaks over time. This study demonstrated methods to optimize GPC properties through additive reinforcement and glass composition tuning.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Effect of Nanoclay on the Structure and Properties of High Density Polyethyle...iosrjce
In this study we prepared high density polyethylene (HDPE)/ clay nanocomposites by melt
compounding in a twin screw extruder with rotational speed of 50rpm and the temperatures of the zones are set
to 180-210°C.Different screw configuration have been used to study the effect of screw elements on the
properties of nanocomposites. screw configuration changed from dispersive to distributive type. Cloisite 15A
was used as the filler and weight percent of clay was fixed to 3wt%. Maleated polyethylene grafted polyolefins
supplied from Reliance ltd. A new combination of maleic anhydride grafted polyethylene prepared in our lab
through grafting also taken as compatibilizer.the samples were then characterized by XRD,FTIR and DSC. The
results showed that PE/clay nanocomposites provide better exfoliation with high dispersive screw
configuration. The addition of clay also increased the dispersion and crystallinity of the composite. The clay
particles helped the nanocomposites to develop toruos path that prevent the leakage of gas through it.
Rheological results indicated an increase in the viscosity with the addition of nano clay to PE. wide angle x-ray
diffraction shows the better exfoliation of nano particle clays in the polymer matrix. The mechanical, thermal
and rheological characteristics were measured by using differential scanning calorimetry (DSC), X-ray
diffraction (XRD). XRD indicates that Compatibilizer –nanoclay ratio plays an important role in the exfoliation
of clay in the polyethylene.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Effect of Nanoclay on the Structure and Properties of High Density Polyethyle...iosrjce
In this study we prepared high density polyethylene (HDPE)/ clay nanocomposites by melt
compounding in a twin screw extruder with rotational speed of 50rpm and the temperatures of the zones are set
to 180-210°C.Different screw configuration have been used to study the effect of screw elements on the
properties of nanocomposites. screw configuration changed from dispersive to distributive type. Cloisite 15A
was used as the filler and weight percent of clay was fixed to 3wt%. Maleated polyethylene grafted polyolefins
supplied from Reliance ltd. A new combination of maleic anhydride grafted polyethylene prepared in our lab
through grafting also taken as compatibilizer.the samples were then characterized by XRD,FTIR and DSC. The
results showed that PE/clay nanocomposites provide better exfoliation with high dispersive screw
configuration. The addition of clay also increased the dispersion and crystallinity of the composite. The clay
particles helped the nanocomposites to develop toruos path that prevent the leakage of gas through it.
Rheological results indicated an increase in the viscosity with the addition of nano clay to PE. wide angle x-ray
diffraction shows the better exfoliation of nano particle clays in the polymer matrix. The mechanical, thermal
and rheological characteristics were measured by using differential scanning calorimetry (DSC), X-ray
diffraction (XRD). XRD indicates that Compatibilizer –nanoclay ratio plays an important role in the exfoliation
of clay in the polyethylene.
Evaluation of Compressive Strength and Water Absorption of Styrene Butadiene...IJMER
In this research, effect of Styrene-Butadiene Rubber (SBR) latex on water absorption and
compressive strength of concrete has been studied. A locally available “RIPSTAR-148” is used as SBR
Latex.
It has been observed that SBR latex improves the internal structure of the latex modified
concrete resulting in considerable reduction in the water absorption value at 28 days of age. However,
at early age, the effect of SBR latex on water absorption is adverse. Same trend is noticed for the
compressive strength; at 7 days of age, SBR latex has negative effect while at 28 days, the addition of
SBR latex in concrete results in enhancement of compressive strength. Based on the results of this
study, latex modified concrete made using “RIPSTAR-148” may be recommended to be used in RC
structures in INDIA. However, for the mixes rich in cement, the dosage of “RIPSTAR-148” needs to be
adjusted to maintain required workability of concrete.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
call for paper 2012, hard copy of journal, research paper publishing, where to publish research paper,
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal,
Effect of Relative Proportion of Pozzolana on Compressive Strength of Concret...CSCJournals
In this experimental and analytic research, the effect of curing regime on various combinations of silica fume and fly ash was investigated in terms of development of compressive strength. Over 24 mixes were prepared with the water-to-binder ratios of 0.45, 0.35 and 0.25 and with differing percentage of additives used as a combination of 2 or 3 binders. The specimens were subjected to five different curing regimes ranging from continuously water cured to continuously air cured. Results show that it is economical to use a combination of silica fume and fly ash rather than using only silica fume for attaining the same strength level. Poor curing condition adversely affect the strength characteristics of pozzolanic concrete than that of OPC concrete. For silica fume concrete, it is necessary to apply water curing for the initial 7 days to explore pozzolainc activity but it is imperative to cure the fly ash concrete for an extended period to utilize its full potential.
Influence of GGBS on Mechanical Properties of Low Traffic Concrete Paver BlocksAbdulRazakBH
Abstract: Supplementary cementitious materials (SCM) are the integral part of modern concrete with significant enhancement
in concrete performance. Low cost of production, low heat of hydration along with improved mechanical properties encourage
the replacement of ordinary Portland cement (OPC) with SCMs to a greater extent. The study focusses on influence of Ground
granulated blast furnace slag (GGBS) as SCM in production of concrete paver blocks. Compressive strength, split tensile
strength, and flexural strength are the properties under consideration. Improved compressive strength and flexural strength was
observed in blended concrete with 20% and 40% GGBS replacement levels.
Keywords: GGBS, M-Sand, Paver Blocks, Split tensile strength, Flexural strength
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Lets together concern about our health and live. Are you one of dental cement consumer?Are you know the composition of the cement itself? Here my thesis/report serve you analytical chemistry description and may answer your curiousness. Check it out in my dental research of GPC.
Evaluation of Compressive Strength and Water Absorption of Styrene Butadiene...IJMER
In this research, effect of Styrene-Butadiene Rubber (SBR) latex on water absorption and
compressive strength of concrete has been studied. A locally available “RIPSTAR-148” is used as SBR
Latex.
It has been observed that SBR latex improves the internal structure of the latex modified
concrete resulting in considerable reduction in the water absorption value at 28 days of age. However,
at early age, the effect of SBR latex on water absorption is adverse. Same trend is noticed for the
compressive strength; at 7 days of age, SBR latex has negative effect while at 28 days, the addition of
SBR latex in concrete results in enhancement of compressive strength. Based on the results of this
study, latex modified concrete made using “RIPSTAR-148” may be recommended to be used in RC
structures in INDIA. However, for the mixes rich in cement, the dosage of “RIPSTAR-148” needs to be
adjusted to maintain required workability of concrete.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
call for paper 2012, hard copy of journal, research paper publishing, where to publish research paper,
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal,
Effect of Relative Proportion of Pozzolana on Compressive Strength of Concret...CSCJournals
In this experimental and analytic research, the effect of curing regime on various combinations of silica fume and fly ash was investigated in terms of development of compressive strength. Over 24 mixes were prepared with the water-to-binder ratios of 0.45, 0.35 and 0.25 and with differing percentage of additives used as a combination of 2 or 3 binders. The specimens were subjected to five different curing regimes ranging from continuously water cured to continuously air cured. Results show that it is economical to use a combination of silica fume and fly ash rather than using only silica fume for attaining the same strength level. Poor curing condition adversely affect the strength characteristics of pozzolanic concrete than that of OPC concrete. For silica fume concrete, it is necessary to apply water curing for the initial 7 days to explore pozzolainc activity but it is imperative to cure the fly ash concrete for an extended period to utilize its full potential.
Influence of GGBS on Mechanical Properties of Low Traffic Concrete Paver BlocksAbdulRazakBH
Abstract: Supplementary cementitious materials (SCM) are the integral part of modern concrete with significant enhancement
in concrete performance. Low cost of production, low heat of hydration along with improved mechanical properties encourage
the replacement of ordinary Portland cement (OPC) with SCMs to a greater extent. The study focusses on influence of Ground
granulated blast furnace slag (GGBS) as SCM in production of concrete paver blocks. Compressive strength, split tensile
strength, and flexural strength are the properties under consideration. Improved compressive strength and flexural strength was
observed in blended concrete with 20% and 40% GGBS replacement levels.
Keywords: GGBS, M-Sand, Paver Blocks, Split tensile strength, Flexural strength
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
Lets together concern about our health and live. Are you one of dental cement consumer?Are you know the composition of the cement itself? Here my thesis/report serve you analytical chemistry description and may answer your curiousness. Check it out in my dental research of GPC.
Comparison of rebound numbers for m20 concrete with silica fumeeSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
An Experimental Study on Durability of Concrete Using Fly Ash & GGBS for M30 ...IJERD Editor
Concrete when subjected to severe environments its durability can significantly decline due to
degradation. Degradation of concrete structures by corrosion is a serious problem and has major economic
implications. In this study, an attempt has been made to study the durability of concrete using the mineral
admixtures like Fly Ash & Ground Granulated Blast Furnace Slag (GGBS) for M30 grade concrete.Cube
Specimens were casted and are immersed in normal water, sea water, H2SO4 of various concentrations and were
tested after 7 days, 28 days & 60 days.
The roles of process parameters on structures and mechanical properties of po...Bambang Afrinaldi
Process parameters are crucial to produce targeted qualities in polypropylene (PP)/clay nanocomposites, due to their roles on the generation of shear and diffusion. Thus, this research aims to observe their effects on structures and properties of PP/clay nanocomposites. Samples were produced by mixing PP, PP grafting maleic anhydride (PP-gMA), and Cloisite 20A at fixed compositions, 88/9/3 wt%, respectively, in an internal mixer with variations on temperatures (210, 220, 230 °C) and speeds (60, 80, 100 rpm). Effect of mixing parameters on nanocomposite structures and properties were investigated from XRD, SEM and flexural properties. The results showed that all samples had intercalated as well as agglomerated structures. Further analysis on XRD and SEM showed that samples produced at
high conditions (230C or 100 rpm) had similar structures. In contrast, low setting sample (210C and 60 rpm), despite its similarity on dispersion level, had longer agglomerates than that of mixed at high settings. Correlated both increase of d-spacing and agglomerates length to flexural properties suggested that modulus was more influenced by dispersion level, while strength
was affected by agglomerates. However, it was worth to note that improvement on dspacing, with availability of long agglomerates might not guarantee modulus and strength improvement due to low interfacial bonding.
An Experimental Study on Short Term Durability and Hardened Properties of Bag...Dr. Amarjeet Singh
This project reports the comparison of bagasse ash and fly ash-bagasse ash based on geopolymer concrete. In which cement is fully replaced by pozzolanic material that is rich in silicon and aluminium like fly ash and bagasse ash referred to as “Geopolymer concrete” which is a contemporary material. Geopolymer concrete was actually manufactured by reusing and recycling of industrial solid wastes and by products. Fly Ash, a by-product of coal obtained from the thermal power plant is plenty available worldwide. Fly ash is used as ingredients in concrete which enhance the properties of concrete and utilization of fly ash is helpful for consumption. Bagasse ash is a final waste product of sugar obtained from the sugar mills. The base material, viz. fly ash and Bagasse ash, is activated by alkaline solution that is sodium hydroxide and sodium silicate to produce a binder which is rich in silica and aluminium. Sample 1 is cement. It is replaced by 100% fly ash geopolymer concrete and trial 2 is 10%, 30% & 50% replaced by Bagasse ash in Geopolymer concrete . The project presents the strength and durability of Bagasse ash based Geopolymer concrete and fly ash and Bagasse ash based Geopolymer concrete.
The addition of small, closely spaced and uniformly dispersed fibers in concrete would act as crack arrester and would substantially improve its static and dynamic properties. The test result shows that the increase in compressive strength of concrete with LIWF for 7 days and 28 days for various percentage of fibers ranges from 3 to 15%.There is increase in flexural strength of concrete as the % of steel increases and decrease in flex. Strength is observed for grater w/c ratio.
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
Builder.ai Founder Sachin Dev Duggal's Strategic Approach to Create an Innova...Ramesh Iyer
In today's fast-changing business world, Companies that adapt and embrace new ideas often need help to keep up with the competition. However, fostering a culture of innovation takes much work. It takes vision, leadership and willingness to take risks in the right proportion. Sachin Dev Duggal, co-founder of Builder.ai, has perfected the art of this balance, creating a company culture where creativity and growth are nurtured at each stage.
Accelerate your Kubernetes clusters with Varnish CachingThijs Feryn
A presentation about the usage and availability of Varnish on Kubernetes. This talk explores the capabilities of Varnish caching and shows how to use the Varnish Helm chart to deploy it to Kubernetes.
This presentation was delivered at K8SUG Singapore. See https://feryn.eu/presentations/accelerate-your-kubernetes-clusters-with-varnish-caching-k8sug-singapore-28-2024 for more details.
Encryption in Microsoft 365 - ExpertsLive Netherlands 2024Albert Hoitingh
In this session I delve into the encryption technology used in Microsoft 365 and Microsoft Purview. Including the concepts of Customer Key and Double Key Encryption.
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
Neuro-symbolic is not enough, we need neuro-*semantic*Frank van Harmelen
Neuro-symbolic (NeSy) AI is on the rise. However, simply machine learning on just any symbolic structure is not sufficient to really harvest the gains of NeSy. These will only be gained when the symbolic structures have an actual semantics. I give an operational definition of semantics as “predictable inference”.
All of this illustrated with link prediction over knowledge graphs, but the argument is general.
2. Glass polyalkenoate cements (GPCs)
are important material for the modern
clinical dentistry
Advantages:
-chemically bond to the apatite mineral
of teeth
-avoid secondary carries
- inherently good adhesion
- have potential to replace amalgam
Limitation
-brittleness
-poor inferior fracture toughness and
wear resistance
3. Due to limitation of GPCs, this study lead to set of
fundamental to investigate alternative in the way
to optimize the application of GPCs in term of
Focused on the optimization of GPCs in term of:
-Compressive strength
-Setting reaction
4. Objectives
1. To follow the setting reaction of GPCs
2. To study influence of MMT on compressive strength of GPC
3. To investigate the influence of Na on the setting reaction of cement
5. GPCs composed of glass powder alumino-silicate and
aqueous solution of polyacrylic acid.
Formation: acid degrade network structure of glass and
releasing metal cations (Ca2+, Na+, or Al3+) [1].
Fig 1:Schematic depiction of the setting reaction of GPCs formation[2]
[1]De Barra, Hill R.G., Influence of alkali metal ions on the fracture properties of glass polyalkenoate (ionomer) cements. Journal of Biomaterial
1998, 19, 495-502.
[2] Technical Product Profile: 3M ESPE Ketac Chem Glass Ionomer Cement. 3M ESPE AG: Seefeld,Germany . Pg:6.
5
6. The COO− groups and the released Al3+ and Ca2+ ions
enables cross linking of these chains, giving a solid network
around the glass particles. The binding of the COO− groups
with Ca2+ ions from the enamel occur and form a chemical
bond between the cement and the tooth structure [3].
Reaction involved is acid-base reaction where glass being a
base , accepts protons from acid even though it is not soluble
in water. The number and type of anions and cations
released from the glass particle will determine the extent of
cross linking in polysalt matrix [4].
[3] Tjalling J., Algera, Cornelis J., Kleverlaan, Birte P.A., Albert J.F., The influence of environmental conditions on the material properties of setting
glass-ionomer cements. Dental materials 2005, 22, 852–856.
[4] De Barra E., Composition structure property relationship in glass ionomer cements. In material science and technology. University of Limerick,
2008.
7. Setting reaction of GPC
- The primary step is hardening step after glass and aqueous
polyacid mix each other about 3-5 minutes.
-Through FTIR study, Crisp and Wilson [5] assigned that a
calcium salt was formed leading to gelation at initial step.
- The secondary mechanism is post-hardening steps. This step
is involves the formation aluminum salt species and contribute
to the improvement of mechanical properties that measured
relative with time
Composition of glass influence setting reaction of GPCs
- Al in the glass structure is important to create negative sites to
be attacked by polyacid.
- Na result the cementlikely to have disportionate influence on
its properties [1]
[1]De Barra, Hill R.G., Influence of alkali metal ions on the fracture properties of glass polyalkenoate (ionomer) cements.
Journal of Biomaterial 1998, 19, 495-502.
[5] Crisp S., Pringuer M.A., Wardleworth D., Wilson A.D., Reaction in glass ionomer cements: II. An infrared spectroscopic
study.J Dent Res 1974, 53, 1414-1419.
8. FTIR technique used : to determine setting reaction by
assigning particular peaks that develop due to acid-base
reaction.
- the absorption of original glass powder is totally different with glasses
that have been produced.
Compressive strength increase with the addition of MMT.
- ADA-MMT addition increase the mean compressive of GPCs [6]
[6] Dowling A.H., Stamboulis A., Fleming J.P., The influence of montmorillonite clay reinforcement on the performance of a glass
ionomer restorative. Journal of dentistry 2006, 34, 802-810.
9. GLASS COMPOSITION
• high temperature (1400 C) melt quench route
Code SiO2 Al2O3 P2O5 CaO CaF2 Na2O
LG3 33.3 22.2 11.1 22.2 11.1 -
LG66 33.3 22.2 11.1 17.8 11.1 4.4
Table 1: Glass composition in mole percentage
10. PREPARATION OF GPC
GPC with MMT GPC without MMT
Glass powder + Glass powder + PAA
PAA + water + water + MMT clay
Ratio : 2 : 1 : 1 Ratio : 2 : 1 : 1 :
2.5wt%
Homogenously mixed and placed
into test mold
- GPCs were kept in test mold at 37 C for 1 hour.
- quenched into liquid nitrogen ( for less 1 hour GPCs)
and dehydrated with ethanol.
- GPCs were stored in water at 37 C
- ageing time: 5 minutes to 28 days
11. CHARACTERIZATION
Compressive strength: Instron compressive machine (5kN load cell at a
loading rate of 1 mm/min)
Setting reaction :Fourier Transform Infrared spectroscopy (range 200-4000 cm-1)
13. Compressive Strength
- due to the maturing and hardening reaction.
- invariant strengths are very dependent on the aging time.
P= 4F
D²
- unit: MPa.
- F : load at fracture force in Newton (N)
- D : average diameter of the specimen in millimeters (mm).
14. 80
80
70
60
70
50
60
40
50 30
20
40
10
30 0
0 5 10 15 20 25 30 0 5 10 15 20 25 30
Figure 2: Compressive strength of LG3 cement Figure 3: Compressive strength of LG66 cement
without and with addition of MMT without and with addition of MMT
• increased slowly between 1 to 7
• increased rapidly in 14 days period days
•Without MMT=53.55 MPa • increased rapidly after 7 days and
•With MMT =74.21 MPa continued even after 28 days
•Without MMT =53.24 MPa
•With MMT =66.16 MPa.
15. increased the compressive value
property of MMT : able to act as filler by intercalation reaction and fill in the
layer within GPCs.
The hydrogen bond that formed between acid and MMT layer also may
influence the increase of strength of the GPCs.
According to Drowling et al. (2006), the formation of hydrogen bond
occurred between carboxylic acid group and amine group of ADA-MMT
have a greater reinforcing effect on the mechanical properties of the
material system to which they have been added.
The amount of MMT used that is 2.5 wt% also suitable for both glasses in
cements formation. Drowling et al. (2006) highlighted that MMT addition with
excess of 2.5 wt% cause in difficulty to mix with the glass.
16. 4.4 mole% of Na2O might cause the differences interaction in
the LG66 cements.
When comparing the trends of compressive strength for both
cements, it was found that LG3 cements showed rapid
increase within 14 days. After 14 days, the compressive
strength became slightly lower.
For LG66 cements, the compressive strength continually
increases even after 28 days.
It shows that the setting reaction of LG3 cements were faster
than LG66 cements. This situation most likely related to the
alkali metal anions leaching process.
Na+ in LG66 ions have tendency to slower the setting reaction
by competes calcium and Ca2+ and Al3+ to bind with
carboxylate group of PAA.
17. At initial aging time, Na+ may disrupt the crosslinking . However, this situation
only temporary and take place at early stage of reaction. Na+ has mobile
properties to move freely and will leave the carboxylate group [7]
(Akinmade and Hill, 1991). Therefore, after Na+ released from carboxylate
group, Ca2+ and Al3+ will replace to form crosslink.
Similar finding was obtained by De Barra and Hill (1998). In their study, they
found that the influence of Na+ content glasses give significant reduction in
compressive strength at early stage of reaction and became considerably
reduced as aging time increase.
[7]Akinmade A.O., Hill R.G., The influence of cement layer thickness on the adhesive bond strength of polyalkenoate
cements. Biomaterials 1991, 13, 931
[1]De Barra, Hill R.G., Influence of alkali metal ions on the fracture properties of glass polyalkenoate (ionomer)
cements. Journal of Biomaterial 1998, 19, 495-502.
18. Before formation
- FTIR spectrum of LG3 glass
- FTIR spectrum of LG66 glass
- FTIR spectrum of PAA
After formation
- FTIR spectra of LG3 cement with/without MMT at various aging time
- FTIR spectra of LG66 cement with/without MMT at various aging time
19. 100 100
80 80
% Intensity
% Intensity
60 60
Si-O (Si) Si-O (Si)
40
Stretch 40
Stretch
20 20
0 0
4000 3500 3000 2500 2000 1500 1000 500 4000 3500 3000 2500 2000 1500 1000 500
Wavenumber, cm-1 Wavenumber, cm-1
Figure 4: Infrared spectrum for LG3 glass Figure 5: Infrared spectrum for LG66 glass
•1050 – 980 cm-1 is the asymmetric Si-O(Si) stretch vibration in the glass
• band intensity near 730 cm-1 are may related to the Al, Ca and/or ions
from the silica network.
• 850 – 500 cm-1 due to extraneous ion such Ca2+ and Na+ that
incorporated in glass phase[8].
[8] Farmer V.C., The infrared spectra of mineral. Mineralogical Soc., London.p 469, 1974.
20. 100
80
% Intensity
60
40
COOH
20
O-H
Stretch
0
4000 3500 3000 2500 2000 1500 1000 500
Wavenumber, cm-1
Figure 6: Infrared spectrum for PAA
1700 – 1660 cm-1 is C=O stretching
3200 cm-1 to 2400 cm-1 gives information of acidity character.
21. For original glass, there was only one
absorption peak between 1050 – 980 cm-
1.
After 5 minutes aging time, two new
peaks already developed
1)1710 – 1390 cm-1: formation of COO-M+
2) 900 cm-1 : hydrated silica gel (Si-OH).
The change of absorption pattern
between 1200 – 900 cm-1 were related to
the evaluation of band as cement
formed.
The stretching vibration observed at 1650
cm-1 due to the binding vibration water
that appeared after the leaching (Davis
and Tomozawa, 1996). Peak at region
3700 to 2400 cm-1 came from O-H
stretch.
22. For original glass, there was only one
absorption peak between 1050 – 980
cm-1.
Generally, the absorption peaks of
LG66 cements were similar with LG3
cements.
Two new peaks developed after 5
minutes set of cements.
1) 1710 – 1400 cm-1 : COO-M+
2) 900 : hydrated silica gel (Si-OH).
The change of absorption pattern
observed between 1200 – 900 cm-1
and the stretching vibration at 1650
cm-1 were also same with LG3
cements. Peak at region 3700 to
2400 cm-1 came from O-H stretch.
23. • As time elapsed, the shoulder peaks at 1570 cm-1 and 1550 cm-1
increase in intensity (Figure 8 & 9) due to formation COO-M+ as metal
ions (Al3+ and Ca2+) crosslink with the carboxyl group in the acid [9].
• In contrast, the intensity of shoulder peak at 1710 cm-1 decreases in
intensity due to uptake of H+ from acid by silica network to form silica
gel layer during the cross linking of metal ions and COO- in cements
formation.
• Setting reaction of LG66 cement is slower than LG3 cement. Na+ in
LG66 cement have tendency to compete with Al3+ and Ca2+ and
delay the crosslinking process [1].
[9] Crisp S., Wilson A.D., Reaction in glass-ionomer cements . The precipitate reaction. J.Dent Res 1974, 53, 1420-1424.
[1] De Barra, Hill R.G., Influence of alkali metal ions on the fracture properties of glass polyalkenoate (ionomer) cements.
Journal of Biomaterial 1998, 19, 495-502.
24. LG66 cement: peak of COO-M+ is
weak - delay reaction of cross
linking due to the presence of
sodium.
LG3
This is also the main reason why
COO-M+
the working time in this stage is
Si-O(Si) too slow and GPCs formed have
LG66 low compressive strength.
shoulder peak Si-O(Si) stretch is
also still very weak. The setting
reaction of LG66 cement
seemed slower than LG3
cement.
Figure 9: Comparison of FTIR spectra of LG3 cement and LG66 Sodium ions have tendency to
cement without MMT at 5 minutes aging time
compete with other ion like
calcium and aluminium cations
and may inhibit the crosslinking
process.
25. Si-O(H)
Si-O(H)
% Intensity
% Intensity
Si-O(Si)
Si-O(Si)
2000 1800 1600 1400 1200 1000 800 2000 1800 1600 1400 1200 1000 800
Wavelength, cm-1 Wavelength, cm-1
Figure 10: Infrared spectra of LG3 glass with and Figure 11: Infrared spectra of LG66 glass with and
without addition of MMT at 5 minutes without addition of MMT at 5 minutes
A slight difference between spectrum at 920 cm-1 that corresponded to hydrated
silica gel.
With addition of MMT, this peak is seemed hardly to observe.
The intensity of this peak was very small compared with glass without MMT. This may
have been because of hardening reaction that took place.
Cements with MMT easily to form hard surface and less working time compare than
cements without MMT.
26. The compressive strength for both GPCs were improved with the
addition of MMT.
LG3 cement achieved 74 Mpa (with MMT) and 53 Mpa (without
MMT).
LG66 cement achieved 66 MPa (with MMT) and 53.24 Mpa (without
MMT).
It proves that MMT able to act as filler by intercalation reaction
within GPCs. The formation of hydrogen bonding also provides the
great effect on the compressive strength.
27. For both GPCs, the peak at1700 cm-1 (COOH) decreased in
intensity.
While peak at1540 cm-1 (COO-M+ ) peak increased in intensity.
The peak at 900cm-1 corresponded silica gel (Si-OH).
Setting reaction of GPCs from LG3 glass was faster than GPCs
from LG66 glass.
28. [1]De Barra, Hill R.G., Influence of alkali metal ions on the fracture properties of glass
polyalkenoate (ionomer) cements. Journal of Biomaterial 1998, 19, 495-502.
[2] Technical Product Profile: 3M ESPE Ketac Chem Glass Ionomer Cement. 3M ESPE AG: Seefeld,Germany .
Pg:6.
[3] Tjalling J., Algera, Cornelis J., Kleverlaan, Birte P.A., Albert J.F., The influence of environmental conditions on
the material properties of setting glass-ionomer cements. Dental materials 2005, 22, 852–856.
[4] De Barra E., Composition structure property relationship in glass ionomer cements. In material science and
technology. University of Limerick, 2008.
[5] Crisp S., Pringuer M.A., Wardleworth D., Wilson A.D., Reaction in glass ionomer cements: II. An infrared
spectroscopic study.J Dent Res 1974, 53, 1414-1419.
[6] Dowling A.H., Stamboulis A., Fleming J.P., The influence of montmorillonite clay reinforcement on the
performance of a glass ionomer restorative. Journal of dentistry 2006, 34, 802-810.
[7]Akinmade A.O., Hill R.G., The influence of cement layer thickness on the adhesive bond strength of
polyalkenoate cements. Biomaterials 1991, 13, 931
[8] Farmer V.C., The infrared spectra of mineral. Mineralogical Soc., London.p 469, 1974.
[9] Crisp S., Wilson A.D., Reaction in glass-ionomer cements . The precipitate reaction. J.Dent Res 1974, 53, 1420-
1424.